Home > Products > State Listing > Wyoming Data
Latest:
 AFDCYS |  AFDRIW |  AFDUNR |
  [top]

000
FXUS65 KRIW 260548
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1048 PM MST TUE NOV 25 2014

.UPDATE...ALL OTHER ADVISORIES AND WARNING REMAIN AS IS FOR NOW.

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

MODERATE TO HEAVY SNOW CONTINUES MUCH OF THE WEST AND NORTH THIS
AFTERNOON. WARMER TEMPERATURES HAVE NOT MATERIALIZED...ESPECIALLY
IN THE LOWER ELEVATIONS AND HAS SERIOUSLY IMPACTED THE SNOW FORECAST.
STILL HANGING IN AT 32 AT AFO WITH SNOW.  MID DAY REPORT OF 7 INCHES
AT ALPINE. ALSO IN THE NORTH IN BIGHORN COUNTY 4-6 INCHES OF SNOW
WITH TEMPS 32 TO 31 POWELL...GREYBULL...WORLAND...COWLEY AND CODY.
HIGH WINDS DEVELOPED AND HAVE BEEN SUSTAINING AT KEMMERER AIRPORT
FRO THE PAST FEW HOURS. OTHER AREAS ALONG I 80 HAVE OCCASIONALLY HIT
HIGH WIND. UPGRADED ALL THE MOUNTAINS TO WINTER STORM WARNING WITH
MANY AREAS ALREADY IN THE 8 TO 11 INCH RANGE. ISSUED WINTER STORM
WARNING FOR BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE
REST OF THE BIGHORN BASIN AND EASTERN JOHNSON COUNTY. UPGRADED
JACKSON HOLE AND STAR VALLEY TO WINTER STORM WARNING. STAR VALLEY
UNTIL 07Z WITH 12Z TERMINATION IN JACKSON HOLE. WINTER WEATHER
ADVISORY FOR UPPER GREEN RIVER BASIN. HIGH WIND WARNING FOR THE
SOUTHWEST AND DUBOIS ZONES GO THROUGH 06Z. NATRONA COUNTY AND WIND
RIVER BASIN WILL SEE SOME SNOW BUT ARE EXPECTED TO BE BELOW ADVISORY
AMOUNTS AND NOT WINDY ENOUGH FOR HIGH WIND. CONDITIONS ARE EXPECTED
TO IMPROVE SLOWLY THROUGH LATE MORNING THEN IMPROVEMENT SHOULD
ACCELERATE. COOLED TEMPERATURES MOST AREAS TONIGHT AND WEDNESDAY.
THE SOUTHWEST WILL HAVE THE LEAST CHANGE IN TEMPERATURES AND WILL BE
VERY WELL MIXED.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

ON WEDNESDAY NIGHT THE AREA OF LINGERING SNOWFALL IN NORTHWEST WY
WILL BE PERPETUATED BY THE CONTINUED STREAM OF PACIFIC MOISTURE FROM
THE NORTHWEST BUT WILL CONTINUE TO DIMINISH AS THE DYNAMICS MOVE OFF
TO THE EAST WITH THE EXITING WEATHER SYSTEM AS THE FLATTENING HIGH
PRESSURE RIDGE...NOW A STRONG RIDGE JUST OFF THE PACIFIC
COAST...BUILDS INTO WYOMING FROM THE WEST. THE STRONG FLOW FROM THE
NORTHWEST WHICH WILL BACK TO THE WEST BY FRIDAY WILL CONTINUE WITHIN
THE FLATTENING RIDGE KEEPING THE WINDS BLOWING IN THE MTNS WITHOUT A
LET UP WED NT THROUGH SATURDAY WITH THE SOUTHWEST WINDS INCREASING
IN SPEED ALONG THE SOUTHERN WIND CORRIDOR KICKING IN BY FRIDAY. AS
THIS RIDGE BUILDS IN...ALMOST ALL AREAS WILL MIX OUT WITH HIGHS IN
THE LOW TO MID 50S EXPECTED IN THE WIND RIVER BASIN...THE LOWER
ELEVATIONS OF JOHNSON AND NATRONA COUNTIES...THE WESTERN PORTION OF
THE BIG HORN BASIN AS WELL AS ACROSS PORTIONS OF SWEETWATER COUNTY
THURSDAY AND FRIDAY MAKING FOR A PLEASANT THANKSGIVING DAY MOST
AREAS. OTHER LOWER ELEVATIONS WILL HAVE HIGHS IN THE 40S WITH 30S TO
LOW 40S IN THE FAR WEST VALLEYS. HIGHS WILL ONLY BE IN THE 40S
ACROSS THE EASTERN BIG HORN BASIN THU/FRI WITH FRESH SNOW COVER IN
PLACE THERE. ONLY ISOLATED SHOWERS ARE EXPECTED IN THE NW MTNS WITH
THE CONTINUED NW TO WEST FLOW DURING THIS TIME FRAME. THEN BY
SATURDAY...SNOWFALL IN THE WEST WITH SOME RAIN MIXED IN WITH THE
SNOW IN THE WESTERN VALLEYS...IS EXPECTED AS THE NEXT NORTHERN
PACIFIC TROUGH BEING DRIVEN BY THE SPINNING POLAR VORTEX SWINGS BY
JUST TO OUR NORTH WITH NORTHERN WY BEING CONSIDERABLY COLDER THEN
CENTRAL AND SOUTHERN WY ON SUNDAY. THE SNOW WILL CONTINUE ON
SATURDAY NIGHT IN THE WEST. DRYING IS EXPECTED SUNDAY. TEMPS WILL
WARM UP MONDAY BEFORE COOLING EVERYWHERE TUE BUT NOT TO THE EXTENT
THAT IS DOES SUNDAY IN THE NORTH AS THE NEXT SPLITTING PACIFIC
TROUGH APPROACHES FROM THE WEST AND WE CAPTURE THE NORTHERN STREAM
ENERGY. THE GFS AND THE EURO ARE IN FAIRLY GOOD AGREEMENT WITH THIS.
KEPT MORE SNOW IN THE FORECAST FOR WESTERN WY MONDAY NIGHT AND
TUESDAY WITH THIS NEXT TROUGH.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

AREAS OF SNOW WILL END BY 15Z IN CENTRAL WY WITH SOME LIGHT SNOW
LINGERING UNTIL 18Z IN NORTHERN WY. AREAS OF MVFR/IFR CONDITIONS
WILL OCCUR. AFTER 18Z VFR CONDITIONS WILL PREVAIL AT THE TERMINAL
SITES. IN THE BIGHORN MOUNTAINS SNOW WILL OCCUR THROUGH LATE
THURSDAY AFTERNOON WITH SNOW SHOWERS LINGERING UNTIL 03Z THURSDAY.
PLEASE SEE INDIVIDUAL TERMINAL FORECASTS FOR MORE DETAILS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

SNOW SHOWERS WILL CONTINUE IN THE MOUNTAIN THROUGH 18Z...THEN
DECREASE IN COVERAGE THROUGH 00Z. EXPECT LOW CLOUDS IN PARTS OF THE
WEST THROUGH 18Z WITH MVFR TO IFR CONDITIONS. IMPROVEMENT WILL OCCUR
AFTER 18Z WITH VFR CONDITIONS PREVAILING AT THE TERMINAL SITES.
EXPECT WINDY CONDITIONS AT KRKS THROUGH 02Z. PLEASE SEE INDIVIDUAL
TERMINAL FORECASTS FOR MORE DETAILS.

&&

.FIRE WEATHER...

COLD SNOWY WINTER WEATHER WITH STRONG WINDS AND LOW MIXING HEIGHTS
WILL PERSIST. VARIOUS WARNINGS AND ADVISORIES ARE IN EFFECT TONIGHT
FOR WIND AND SNOW. HEAVY SNOW ACCUMULATION IS POSSIBLE IN THE
NORTHERN AND WESTERN MOUNTAINS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

UPDATE...HATTINGS
SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER












  [top]

000
FXUS65 KCYS 260529
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1029 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 1016 PM MST TUE NOV 25 2014

WYDOT SENSORS OVER THE SOUTH LARAMIE RANGE LATE THIS EVENING ARE
REPORTING WIND SPEEDS IN THE 30 MPH RANGE OVER THE SUMMIT. LATEST
WRKHGT PRODUCT EASING CRAIG TO CASPER 850 AND 700MB HEIGHT
GRADIENTS OVERNIGHT BEFORE PICKING THEM UP AGAIN TOMORROW
AFTERNOON. WENT AHEAD AND CANCELLED THE HGH WIND WARNING FOR THE
SOUTH LARAMIE RANGE EARLY WITH THIS UPDATE. DID KEEP THE ARLINGTON
ZONE GOING AS FORECAST AS THEIR WINDS OUT THERE ARE GUSTING TO THE
LOW 40S. UPDATES HAVE BEEN SENT.

UPDATE ISSUED AT 805 PM MST TUE NOV 25 2014

SEEING RAPIDLY COOLING CLOUD TOPS ON IR IMAGERY ACROSS NORTH
CENTRAL WYOMING THIS EVENING JUST NORTH OF CONVERSE COUNTY.
WEBCAMS NEAR NATURAL BRIDGE SHOWING I-25 SNOW COVERED WITH REDUCED
VISIBILITIES. GOT A REPORT OUT OF DOUGLAS OF 3 INCHES OF SNOW...SO
WENT AHEAD AND ADDED CONVERSE COUNTY TO THE WINTER WEATHER
ADVISORY. LOOKING AT WIND REPORTS FURTHER SOUTH...FRONT ALREADY
HAS MADE IT THROUGH BORDEAUX AND WINDS OUT WEST IN CARBON AND
NORTHERN ALBANY COUNTIES CONTINUE TO DECREASE. WENT AHEAD AND
CANCELLED THE HIGH WIND WARNING FOR THESE AREAS EARLY. UPDATES
HAVE BEEN SENT.

UPDATE ISSUED AT 700 PM MST TUE NOV 25 2014

LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1016 PM MST TUE NOV 25 2014

LATEST HRRR GUIDANCE USED FOR THIS TAF PACKAGE. FRONT CONTINUES TO
PUSH SOUTHWEST OVERNIGHT WITH SNOW DEVELOPING WEST OF THE LARAMIE
RANGE. LARAMIE ALREADY DOWN TO LESS THAN 2 MILES IN SNOW AND WOULD
EXPECT THIS TO CONTINUE THROUGH 12Z BEFORE IMPROVING. HRRR SHOWING
KRWL STAYING DOWN...THOUGH MOST LIFR/IFR SOUTH OF THE AIRPORT.
ANOTHER WINDY DAY FOR WEDNESDAY.

&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ101-103-
     106-107-116>119.

NE...NONE.
&&

$$

UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 260529
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1029 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 1016 PM MST TUE NOV 25 2014

WYDOT SENSORS OVER THE SOUTH LARAMIE RANGE LATE THIS EVENING ARE
REPORTING WIND SPEEDS IN THE 30 MPH RANGE OVER THE SUMMIT. LATEST
WRKHGT PRODUCT EASING CRAIG TO CASPER 850 AND 700MB HEIGHT
GRADIENTS OVERNIGHT BEFORE PICKING THEM UP AGAIN TOMORROW
AFTERNOON. WENT AHEAD AND CANCELLED THE HGH WIND WARNING FOR THE
SOUTH LARAMIE RANGE EARLY WITH THIS UPDATE. DID KEEP THE ARLINGTON
ZONE GOING AS FORECAST AS THEIR WINDS OUT THERE ARE GUSTING TO THE
LOW 40S. UPDATES HAVE BEEN SENT.

UPDATE ISSUED AT 805 PM MST TUE NOV 25 2014

SEEING RAPIDLY COOLING CLOUD TOPS ON IR IMAGERY ACROSS NORTH
CENTRAL WYOMING THIS EVENING JUST NORTH OF CONVERSE COUNTY.
WEBCAMS NEAR NATURAL BRIDGE SHOWING I-25 SNOW COVERED WITH REDUCED
VISIBILITIES. GOT A REPORT OUT OF DOUGLAS OF 3 INCHES OF SNOW...SO
WENT AHEAD AND ADDED CONVERSE COUNTY TO THE WINTER WEATHER
ADVISORY. LOOKING AT WIND REPORTS FURTHER SOUTH...FRONT ALREADY
HAS MADE IT THROUGH BORDEAUX AND WINDS OUT WEST IN CARBON AND
NORTHERN ALBANY COUNTIES CONTINUE TO DECREASE. WENT AHEAD AND
CANCELLED THE HIGH WIND WARNING FOR THESE AREAS EARLY. UPDATES
HAVE BEEN SENT.

UPDATE ISSUED AT 700 PM MST TUE NOV 25 2014

LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1016 PM MST TUE NOV 25 2014

LATEST HRRR GUIDANCE USED FOR THIS TAF PACKAGE. FRONT CONTINUES TO
PUSH SOUTHWEST OVERNIGHT WITH SNOW DEVELOPING WEST OF THE LARAMIE
RANGE. LARAMIE ALREADY DOWN TO LESS THAN 2 MILES IN SNOW AND WOULD
EXPECT THIS TO CONTINUE THROUGH 12Z BEFORE IMPROVING. HRRR SHOWING
KRWL STAYING DOWN...THOUGH MOST LIFR/IFR SOUTH OF THE AIRPORT.
ANOTHER WINDY DAY FOR WEDNESDAY.

&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ101-103-
     106-107-116>119.

NE...NONE.
&&

$$

UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RJM



  [top]

000
FXUS63 KUNR 260421
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
921 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 916 PM MST TUE NOV 25 2014

SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014

WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON






000
FXUS63 KUNR 260421
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
921 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 916 PM MST TUE NOV 25 2014

SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014

WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON






000
FXUS63 KUNR 260421
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
921 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 916 PM MST TUE NOV 25 2014

SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014

WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON






000
FXUS63 KUNR 260421
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
921 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 916 PM MST TUE NOV 25 2014

SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014

WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON






000
FXUS65 KCYS 260308
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
808 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 805 PM MST TUE NOV 25 2014

SEEING RAPIDLY COOLING CLOUD TOPS ON IR IMAGERY ACROSS NORTH
CENTRAL WYOMING THIS EVENING JUST NORTH OF CONVERSE COUNTY.
WEBCAMS NEAR NATURAL BRIDGE SHOWING I-25 SNOW COVERED WITH REDUCED
VISIBILITIES. GOT A REPORT OUT OF DOUGLAS OF 3 INCHES OF SNOW...SO
WENT AHEAD AND ADDED CONVERSE COUNTY TO THE WINTER WEATHER
ADVISORY. LOOKING AT WIND REPORTS FURTHER SOUTH...FRONT ALREADY
HAS MADE IT THROUGH BORDEAUX AND WINDS OUT WEST IN CARBON AND
NORTHERN ALBANY COUNTIES CONTINUE TO DECREASE. WENT AHEAD AND
CANCELLED THE HIGH WIND WARNING FOR THESE AREAS EARLY. UPDATES
HAVE BEEN SENT.

UPDATE ISSUED AT 700 PM MST TUE NOV 25 2014

LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDS REMAIN VERY STRONG ACROSS SOUTHEAST WYOMING WITH AN OCCASIONAL
GUST TO 45 KTS POSSIBLE THROUGH 01Z. A COLD FRONT WILL MOVE THROUGH
THE AREA THIS EVENING...PROVIDING SOME TEMPORARY RELIEF TO HIGH WIND
FOR MOST AREAS. RAIN AND SNOW SHOWERS ARE ALREADY STARTING TO BECOME
MORE WIDESPREAD LATE THIS AFTERNOON. A BAND OF MODERATE SNOW SHOULD
TAKE SHAPE BETWEEN 03-09Z ALONG AND SOUTHWEST OF A LINE FROM DGW TO
SNY WITH SEVERAL INCHES OF ACCUMULATION POSSIBLE. VSBYS WILL LIKELY
BE IFR TO LIFR BENEATH THIS BAND. SNOW SHOWERS MAY SPREAD FURTHER
INTO THE NEBRASKA PANHANDLE ON WED MORNING. WINDS ARE EXPECTED TO
INCREASE AGAIN OVER THE WYOMING TERMINALS ON WED AFTERNOON ALONG
WITH THE POSSIBILITY OF MOUNTAIN WAVE TURBULENCE.


&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ101-103-
     106-107-116>119.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ116-117.

NE...NONE.
&&

$$

UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...RJM




000
FXUS65 KRIW 260215
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
715 PM MST TUE NOV 25 2014

.UPDATE...WITH THE WINDS DECREASING IN THE SOUTH WE HAVE CANCELLED
THE HIGH WIND WARNING. WE ALSO CANCELLED IN DUBOIS SINCE THE HIGH
WINDS HAVE NOT MATERIALIZED. ALL OTHER ADVSIORIES AND WARNING REMAIN
AS IS.

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

MODERATE TO HEAVY SNOW CONTINUES MUCH OF THE WEST AND NORTH THIS
AFTERNOON. WARMER TEMPERATURES HAVE NOT MATERIALIZED...ESPECIALLY
IN THE LOWER ELEVATIONS AND HAS SERIOUSLY IMPACTED THE SNOW FORECAST.
STILL HANGING IN AT 32 AT AFO WITH SNOW.  MID DAY REPORT OF 7 INCHES
AT ALPINE. ALSO IN THE NORTH IN BIGHORN COUNTY 4-6 INCHES OF SNOW
WITH TEMPS 32 TO 31 POWELL...GREYBULL...WORLAND...COWLEY AND CODY.
HIGH WINDS DEVELOPED AND HAVE BEEN SUSTAINING AT KEMMERER AIRPORT
FRO THE PAST FEW HOURS. OTHER AREAS ALONG I 80 HAVE OCCASIONALLY HIT
HIGH WIND. UPGRADED ALL THE MOUNTAINS TO WINTER STORM WARNING WITH
MANY AREAS ALREADY IN THE 8 TO 11 INCH RANGE. ISSUED WINTER STORM
WARNING FOR BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE
REST OF THE BIGHORN BASIN AND EASTERN JOHNSON COUNTY. UPGRADED
JACKSON HOLE AND STAR VALLEY TO WINTER STORM WARNING. STAR VALLEY
UNTIL 07Z WITH 12Z TERMINATION IN JACKSON HOLE. WINTER WEATHER
ADVISORY FOR UPPER GREEN RIVER BASIN. HIGH WIND WARNING FOR THE
SOUTHWEST AND DUBOIS ZONES GO THROUGH 06Z. NATRONA COUNTY AND WIND
RIVER BASIN WILL SEE SOME SNOW BUT ARE EXPECTED TO BE BELOW ADVISORY
AMOUNTS AND NOT WINDY ENOUGH FOR HIGH WIND. CONDITIONS ARE EXPECTED
TO IMPROVE SLOWLY THROUGH LATE MORNING THEN IMPROVEMENT SHOULD
ACCELERATE. COOLED TEMPERATURES MOST AREAS TONIGHT AND WEDNESDAY.
THE SOUTHWEST WILL HAVE THE LEAST CHANGE IN TEMPERATURES AND WILL BE
VERY WELL MIXED.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

ON WEDNESDAY NIGHT THE AREA OF LINGERING SNOWFALL IN NORTHWEST WY
WILL BE PERPETUATED BY THE CONTINUED STREAM OF PACIFIC MOISTURE FROM
THE NORTHWEST BUT WILL CONTINUE TO DIMINISH AS THE DYNAMICS MOVE OFF
TO THE EAST WITH THE EXITING WEATHER SYSTEM AS THE FLATTENING HIGH
PRESSURE RIDGE...NOW A STRONG RIDGE JUST OFF THE PACIFIC
COAST...BUILDS INTO WYOMING FROM THE WEST. THE STRONG FLOW FROM THE
NORTHWEST WHICH WILL BACK TO THE WEST BY FRIDAY WILL CONTINUE WITHIN
THE FLATTENING RIDGE KEEPING THE WINDS BLOWING IN THE MTNS WITHOUT A
LET UP WED NT THROUGH SATURDAY WITH THE SOUTHWEST WINDS INCREASING
IN SPEED ALONG THE SOUTHERN WIND CORRIDOR KICKING IN BY FRIDAY. AS
THIS RIDGE BUILDS IN...ALMOST ALL AREAS WILL MIX OUT WITH HIGHS IN
THE LOW TO MID 50S EXPECTED IN THE WIND RIVER BASIN...THE LOWER
ELEVATIONS OF JOHNSON AND NATRONA COUNTIES...THE WESTERN PORTION OF
THE BIG HORN BASIN AS WELL AS ACROSS PORTIONS OF SWEETWATER COUNTY
THURSDAY AND FRIDAY MAKING FOR A PLEASANT THANKSGIVING DAY MOST
AREAS. OTHER LOWER ELEVATIONS WILL HAVE HIGHS IN THE 40S WITH 30S TO
LOW 40S IN THE FAR WEST VALLEYS. HIGHS WILL ONLY BE IN THE 40S
ACROSS THE EASTERN BIG HORN BASIN THU/FRI WITH FRESH SNOW COVER IN
PLACE THERE. ONLY ISOLATED SHOWERS ARE EXPECTED IN THE NW MTNS WITH
THE CONTINUED NW TO WEST FLOW DURING THIS TIME FRAME. THEN BY
SATURDAY...SNOWFALL IN THE WEST WITH SOME RAIN MIXED IN WITH THE
SNOW IN THE WESTERN VALLEYS...IS EXPECTED AS THE NEXT NORTHERN
PACIFIC TROUGH BEING DRIVEN BY THE SPINNING POLAR VORTEX SWINGS BY
JUST TO OUR NORTH WITH NORTHERN WY BEING CONSIDERABLY COLDER THEN
CENTRAL AND SOUTHERN WY ON SUNDAY. THE SNOW WILL CONTINUE ON
SATURDAY NIGHT IN THE WEST. DRYING IS EXPECTED SUNDAY. TEMPS WILL
WARM UP MONDAY BEFORE COOLING EVERYWHERE TUE BUT NOT TO THE EXTENT
THAT IS DOES SUNDAY IN THE NORTH AS THE NEXT SPLITTING PACIFIC
TROUGH APPROACHES FROM THE WEST AND WE CAPTURE THE NORTHERN STREAM
ENERGY. THE GFS AND THE EURO ARE IN FAIRLY GOOD AGREEMENT WITH THIS.
KEPT MORE SNOW IN THE FORECAST FOR WESTERN WY MONDAY NIGHT AND
TUESDAY WITH THIS NEXT TROUGH.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE THROUGH 00Z THURSDAY.  TO THE SOUTH VFR
CONDITIONS ARE EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN
NATRONA COUNTIES UNTIL 02Z THEN IFR/MVFR CONDITIONS WILL SPREAD
SOUTH BEHIND THE COLD FRONT UP TO THE CONTINENTAL DIVIDE BY 05Z.
STRONG WEST WINDS 30 TO 40 KTS WITH GUSTS TO 60KTS ARE EXPECTED
ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS
WILL SHIFT TO THE NORTH AS A COLD FRONT MOVES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 15Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 15Z TO 18Z. STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z THEN WILL GRADUALLY DIMINISH.

&&

.FIRE WEATHER...

COLD SNOWY WINTER WEATHER WITH STRONG WINDS AND LOW MIXING HEIGHTS
WILL PERSIST. VARIOUS WARNINGS AND ADVISORIES ARE IN EFFECT TONIGHT
FOR WIND AND SNOW. HEAVY SNOW ACCUMULATION IS POSSIBLE IN THE
NORTHERN AND WESTERN MOUNTAINS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

UPDATE...HATTINGS
SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER











000
FXUS65 KRIW 260215
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
715 PM MST TUE NOV 25 2014

.UPDATE...WITH THE WINDS DECREASING IN THE SOUTH WE HAVE CANCELLED
THE HIGH WIND WARNING. WE ALSO CANCELLED IN DUBOIS SINCE THE HIGH
WINDS HAVE NOT MATERIALIZED. ALL OTHER ADVSIORIES AND WARNING REMAIN
AS IS.

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

MODERATE TO HEAVY SNOW CONTINUES MUCH OF THE WEST AND NORTH THIS
AFTERNOON. WARMER TEMPERATURES HAVE NOT MATERIALIZED...ESPECIALLY
IN THE LOWER ELEVATIONS AND HAS SERIOUSLY IMPACTED THE SNOW FORECAST.
STILL HANGING IN AT 32 AT AFO WITH SNOW.  MID DAY REPORT OF 7 INCHES
AT ALPINE. ALSO IN THE NORTH IN BIGHORN COUNTY 4-6 INCHES OF SNOW
WITH TEMPS 32 TO 31 POWELL...GREYBULL...WORLAND...COWLEY AND CODY.
HIGH WINDS DEVELOPED AND HAVE BEEN SUSTAINING AT KEMMERER AIRPORT
FRO THE PAST FEW HOURS. OTHER AREAS ALONG I 80 HAVE OCCASIONALLY HIT
HIGH WIND. UPGRADED ALL THE MOUNTAINS TO WINTER STORM WARNING WITH
MANY AREAS ALREADY IN THE 8 TO 11 INCH RANGE. ISSUED WINTER STORM
WARNING FOR BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE
REST OF THE BIGHORN BASIN AND EASTERN JOHNSON COUNTY. UPGRADED
JACKSON HOLE AND STAR VALLEY TO WINTER STORM WARNING. STAR VALLEY
UNTIL 07Z WITH 12Z TERMINATION IN JACKSON HOLE. WINTER WEATHER
ADVISORY FOR UPPER GREEN RIVER BASIN. HIGH WIND WARNING FOR THE
SOUTHWEST AND DUBOIS ZONES GO THROUGH 06Z. NATRONA COUNTY AND WIND
RIVER BASIN WILL SEE SOME SNOW BUT ARE EXPECTED TO BE BELOW ADVISORY
AMOUNTS AND NOT WINDY ENOUGH FOR HIGH WIND. CONDITIONS ARE EXPECTED
TO IMPROVE SLOWLY THROUGH LATE MORNING THEN IMPROVEMENT SHOULD
ACCELERATE. COOLED TEMPERATURES MOST AREAS TONIGHT AND WEDNESDAY.
THE SOUTHWEST WILL HAVE THE LEAST CHANGE IN TEMPERATURES AND WILL BE
VERY WELL MIXED.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

ON WEDNESDAY NIGHT THE AREA OF LINGERING SNOWFALL IN NORTHWEST WY
WILL BE PERPETUATED BY THE CONTINUED STREAM OF PACIFIC MOISTURE FROM
THE NORTHWEST BUT WILL CONTINUE TO DIMINISH AS THE DYNAMICS MOVE OFF
TO THE EAST WITH THE EXITING WEATHER SYSTEM AS THE FLATTENING HIGH
PRESSURE RIDGE...NOW A STRONG RIDGE JUST OFF THE PACIFIC
COAST...BUILDS INTO WYOMING FROM THE WEST. THE STRONG FLOW FROM THE
NORTHWEST WHICH WILL BACK TO THE WEST BY FRIDAY WILL CONTINUE WITHIN
THE FLATTENING RIDGE KEEPING THE WINDS BLOWING IN THE MTNS WITHOUT A
LET UP WED NT THROUGH SATURDAY WITH THE SOUTHWEST WINDS INCREASING
IN SPEED ALONG THE SOUTHERN WIND CORRIDOR KICKING IN BY FRIDAY. AS
THIS RIDGE BUILDS IN...ALMOST ALL AREAS WILL MIX OUT WITH HIGHS IN
THE LOW TO MID 50S EXPECTED IN THE WIND RIVER BASIN...THE LOWER
ELEVATIONS OF JOHNSON AND NATRONA COUNTIES...THE WESTERN PORTION OF
THE BIG HORN BASIN AS WELL AS ACROSS PORTIONS OF SWEETWATER COUNTY
THURSDAY AND FRIDAY MAKING FOR A PLEASANT THANKSGIVING DAY MOST
AREAS. OTHER LOWER ELEVATIONS WILL HAVE HIGHS IN THE 40S WITH 30S TO
LOW 40S IN THE FAR WEST VALLEYS. HIGHS WILL ONLY BE IN THE 40S
ACROSS THE EASTERN BIG HORN BASIN THU/FRI WITH FRESH SNOW COVER IN
PLACE THERE. ONLY ISOLATED SHOWERS ARE EXPECTED IN THE NW MTNS WITH
THE CONTINUED NW TO WEST FLOW DURING THIS TIME FRAME. THEN BY
SATURDAY...SNOWFALL IN THE WEST WITH SOME RAIN MIXED IN WITH THE
SNOW IN THE WESTERN VALLEYS...IS EXPECTED AS THE NEXT NORTHERN
PACIFIC TROUGH BEING DRIVEN BY THE SPINNING POLAR VORTEX SWINGS BY
JUST TO OUR NORTH WITH NORTHERN WY BEING CONSIDERABLY COLDER THEN
CENTRAL AND SOUTHERN WY ON SUNDAY. THE SNOW WILL CONTINUE ON
SATURDAY NIGHT IN THE WEST. DRYING IS EXPECTED SUNDAY. TEMPS WILL
WARM UP MONDAY BEFORE COOLING EVERYWHERE TUE BUT NOT TO THE EXTENT
THAT IS DOES SUNDAY IN THE NORTH AS THE NEXT SPLITTING PACIFIC
TROUGH APPROACHES FROM THE WEST AND WE CAPTURE THE NORTHERN STREAM
ENERGY. THE GFS AND THE EURO ARE IN FAIRLY GOOD AGREEMENT WITH THIS.
KEPT MORE SNOW IN THE FORECAST FOR WESTERN WY MONDAY NIGHT AND
TUESDAY WITH THIS NEXT TROUGH.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE THROUGH 00Z THURSDAY.  TO THE SOUTH VFR
CONDITIONS ARE EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN
NATRONA COUNTIES UNTIL 02Z THEN IFR/MVFR CONDITIONS WILL SPREAD
SOUTH BEHIND THE COLD FRONT UP TO THE CONTINENTAL DIVIDE BY 05Z.
STRONG WEST WINDS 30 TO 40 KTS WITH GUSTS TO 60KTS ARE EXPECTED
ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS
WILL SHIFT TO THE NORTH AS A COLD FRONT MOVES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 15Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 15Z TO 18Z. STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z THEN WILL GRADUALLY DIMINISH.

&&

.FIRE WEATHER...

COLD SNOWY WINTER WEATHER WITH STRONG WINDS AND LOW MIXING HEIGHTS
WILL PERSIST. VARIOUS WARNINGS AND ADVISORIES ARE IN EFFECT TONIGHT
FOR WIND AND SNOW. HEAVY SNOW ACCUMULATION IS POSSIBLE IN THE
NORTHERN AND WESTERN MOUNTAINS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

UPDATE...HATTINGS
SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER










000
FXUS65 KCYS 260203
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
703 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 700 PM MST TUE NOV 25 2014

LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDS REMAIN VERY STRONG ACROSS SOUTHEAST WYOMING WITH AN OCCASIONAL
GUST TO 45 KTS POSSIBLE THROUGH 01Z. A COLD FRONT WILL MOVE THROUGH
THE AREA THIS EVENING...PROVIDING SOME TEMPORARY RELIEF TO HIGH WIND
FOR MOST AREAS. RAIN AND SNOW SHOWERS ARE ALREADY STARTING TO BECOME
MORE WIDESPREAD LATE THIS AFTERNOON. A BAND OF MODERATE SNOW SHOULD
TAKE SHAPE BETWEEN 03-09Z ALONG AND SOUTHWEST OF A LINE FROM DGW TO
SNY WITH SEVERAL INCHES OF ACCUMULATION POSSIBLE. VSBYS WILL LIKELY
BE IFR TO LIFR BENEATH THIS BAND. SNOW SHOWERS MAY SPREAD FURTHER
INTO THE NEBRASKA PANHANDLE ON WED MORNING. WINDS ARE EXPECTED TO
INCREASE AGAIN OVER THE WYOMING TERMINALS ON WED AFTERNOON ALONG
WITH THE POSSIBILITY OF MOUNTAIN WAVE TURBULENCE.


&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-116-117.

     WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ106-107-
     116>119.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

NE...NONE.
&&

$$

UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...RJM



000
FXUS65 KCYS 260203
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
703 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 700 PM MST TUE NOV 25 2014

LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDS REMAIN VERY STRONG ACROSS SOUTHEAST WYOMING WITH AN OCCASIONAL
GUST TO 45 KTS POSSIBLE THROUGH 01Z. A COLD FRONT WILL MOVE THROUGH
THE AREA THIS EVENING...PROVIDING SOME TEMPORARY RELIEF TO HIGH WIND
FOR MOST AREAS. RAIN AND SNOW SHOWERS ARE ALREADY STARTING TO BECOME
MORE WIDESPREAD LATE THIS AFTERNOON. A BAND OF MODERATE SNOW SHOULD
TAKE SHAPE BETWEEN 03-09Z ALONG AND SOUTHWEST OF A LINE FROM DGW TO
SNY WITH SEVERAL INCHES OF ACCUMULATION POSSIBLE. VSBYS WILL LIKELY
BE IFR TO LIFR BENEATH THIS BAND. SNOW SHOWERS MAY SPREAD FURTHER
INTO THE NEBRASKA PANHANDLE ON WED MORNING. WINDS ARE EXPECTED TO
INCREASE AGAIN OVER THE WYOMING TERMINALS ON WED AFTERNOON ALONG
WITH THE POSSIBILITY OF MOUNTAIN WAVE TURBULENCE.


&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-116-117.

     WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ106-107-
     116>119.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

NE...NONE.
&&

$$

UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...RJM




000
FXUS65 KCYS 252332
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
432 PM MST TUE NOV 25 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014

FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.

MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014

MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDS REMAIN VERY STRONG ACROSS SOUTHEAST WYOMING WITH AN OCCASIONAL
GUST TO 45 KTS POSSIBLE THROUGH 01Z. A COLD FRONT WILL MOVE THROUGH
THE AREA THIS EVENING...PROVIDING SOME TEMPORARY RELIEF TO HIGH WIND
FOR MOST AREAS. RAIN AND SNOW SHOWERS ARE ALREADY STARTING TO BECOME
MORE WIDESPREAD LATE THIS AFTERNOON. A BAND OF MODERATE SNOW SHOULD
TAKE SHAPE BETWEEN 03-09Z ALONG AND SOUTHWEST OF A LINE FROM DGW TO
SNY WITH SEVERAL INCHES OF ACCUMULATION POSSIBLE. VSBYS WILL LIKELY
BE IFR TO LIFR BENEATH THIS BAND. SNOW SHOWERS MAY SPREAD FURTHER
INTO THE NEBRASKA PANHANDLE ON WED MORNING. WINDS ARE EXPECTED TO
INCREASE AGAIN OVER THE WYOMING TERMINALS ON WED AFTERNOON ALONG
WITH THE POSSIBILITY OF MOUNTAIN WAVE TURBULENCE.

&&

.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014

WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-116-117.

     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 2 PM MST
     WEDNESDAY FOR WYZ106-107-116>119.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR WYZ107-113-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...RJM



000
FXUS63 KUNR 252311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
411 PM MST TUE NOV 25 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 406 PM MST TUE NOV 25 2014

NW WINDS WILL INCREASE FURTHER THIS EVENING...GUSTING OVER 40KTS
AT TIMES ESPECIALLY OVER NWRN SD...AS A COLD FRONT MOVES THROUGH.
-SN WILL CONTINUE THROUGH TONIGHT INTO WED...ESPECIALLY OVER NERN
WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD ACRS
THE REGION TONIGHT AND CONTINUE THROUGH THE DAY ON WED...WITH SOME
LIFR CONDITIONS POSSIBLE ACRS NERN WY INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON







000
FXUS63 KUNR 252311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
411 PM MST TUE NOV 25 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 406 PM MST TUE NOV 25 2014

NW WINDS WILL INCREASE FURTHER THIS EVENING...GUSTING OVER 40KTS
AT TIMES ESPECIALLY OVER NWRN SD...AS A COLD FRONT MOVES THROUGH.
-SN WILL CONTINUE THROUGH TONIGHT INTO WED...ESPECIALLY OVER NERN
WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD ACRS
THE REGION TONIGHT AND CONTINUE THROUGH THE DAY ON WED...WITH SOME
LIFR CONDITIONS POSSIBLE ACRS NERN WY INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON







000
FXUS63 KUNR 252311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
411 PM MST TUE NOV 25 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 406 PM MST TUE NOV 25 2014

NW WINDS WILL INCREASE FURTHER THIS EVENING...GUSTING OVER 40KTS
AT TIMES ESPECIALLY OVER NWRN SD...AS A COLD FRONT MOVES THROUGH.
-SN WILL CONTINUE THROUGH TONIGHT INTO WED...ESPECIALLY OVER NERN
WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD ACRS
THE REGION TONIGHT AND CONTINUE THROUGH THE DAY ON WED...WITH SOME
LIFR CONDITIONS POSSIBLE ACRS NERN WY INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON







000
FXUS63 KUNR 252311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
411 PM MST TUE NOV 25 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 406 PM MST TUE NOV 25 2014

NW WINDS WILL INCREASE FURTHER THIS EVENING...GUSTING OVER 40KTS
AT TIMES ESPECIALLY OVER NWRN SD...AS A COLD FRONT MOVES THROUGH.
-SN WILL CONTINUE THROUGH TONIGHT INTO WED...ESPECIALLY OVER NERN
WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD ACRS
THE REGION TONIGHT AND CONTINUE THROUGH THE DAY ON WED...WITH SOME
LIFR CONDITIONS POSSIBLE ACRS NERN WY INTO THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
     032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON







000
FXUS65 KRIW 252200
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MST TUE NOV 25 2014

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

MODERATE TO HEAVY SNOW CONTINUES MUCH OF THE WEST AND NORTH THIS
AFTERNOON. WARMER TEMPERATURES HAVE NOT MATERIALIZED...ESPECIALLY
IN THE LOWER ELEVATIONS AND HAS SERIOUSLY IMPACTED THE SNOW FORECAST.
STILL HANGING IN AT 32 AT AFO WITH SNOW.  MID DAY REPORT OF 7 INCHES
AT ALPINE. ALSO IN THE NORTH IN BIGHORN COUNTY 4-6 INCHES OF SNOW WITH
TEMPS 32 TO 31 POWELL...GREYBULL...WORLAND...COWLEY AND CODY. HIGH WINDS
DEVELOPED AND HAVE BEEN SUSTAINING AT KEMMERER AIRPORT FRO THE
PAST FEW HOURS. OTHER AREAS ALONG I 80 HAVE OCCASIONALLY HIT HIGH
WIND. UPGRADED ALL THE MOUNTAINS TO WINTER STORM WARNING WITH MANY
AREAS ALREADY IN THE 8 TO 11 INCH RANGE. ISSUED WINTER STORM
WARNING FOR BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE
REST OF THE BIGHORN BASIN AND EASTERN JOHNSON COUNTY. UPGRADED
JACKSON HOLE AND STAR VALLEY TO WINTER STORM WARNING. STAR VALLEY
UNTIL 07Z WITH 12Z TERMINATION IN JACKSON HOLE. WINTER WEATHER
ADVISORY FOR UPPER GREEN RIVER BASIN. HIGH WIND WARNING FOR THE
SOUTHWEST AND DUBOIS ZONES GO THROUGH 06Z. NATRONA COUNTY AND WIND
RIVER BASIN WILL SEE SOME SNOW BUT ARE EXPECTED TO BE BELOW
ADVISORY AMOUNTS AND NOT WINDY ENOUGH FOR HIGH WIND. CONDITIONS ARE
EXPECTED TO IMPROVE SLOWLY THROUGH LATE MORNING THEN IMPROVEMENT
SHOULD ACCELERATE. COOLED TEMPERATURES MOST AREAS TONIGHT AND WEDNESDAY.
THE SOUTHWEST WILL HAVE THE LEAST CHANGE IN TEMPERATURES AND WILL
BE VERY WELL MIXED.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

ON WEDNESDAY NIGHT THE AREA OF LINGERING SNOWFALL IN NORTHWEST WY
WILL BE PERPETUATED BY THE CONTINUED STREAM OF PACIFIC MOISTURE FROM
THE NORTHWEST BUT WILL CONTINUE TO DIMINISH AS THE DYNAMICS MOVE OFF
TO THE EAST WITH THE EXITING WEATHER SYSTEM AS THE FLATTENING HIGH
PRESSURE RIDGE...NOW A STRONG RIDGE JUST OFF THE PACIFIC
COAST...BUILDS INTO WYOMING FROM THE WEST. THE STRONG FLOW FROM THE
NORTHWEST WHICH WILL BACK TO THE WEST BY FRIDAY WILL CONTINUE WITHIN
THE FLATTENING RIDGE KEEPING THE WINDS BLOWING IN THE MTNS WITHOUT A
LET UP WED NT THROUGH SATURDAY WITH THE SOUTHWEST WINDS INCREASING
IN SPEED ALONG THE SOUTHERN WIND CORRIDOR KICKING IN BY FRIDAY. AS
THIS RIDGE BUILDS IN...ALMOST ALL AREAS WILL MIX OUT WITH HIGHS IN
THE LOW TO MID 50S EXPECTED IN THE WIND RIVER BASIN...THE LOWER
ELEVATIONS OF JOHNSON AND NATRONA COUNTIES...THE WESTERN PORTION OF
THE BIG HORN BASIN AS WELL AS ACROSS PORTIONS OF SWEETWATER COUNTY
THURSDAY AND FRIDAY MAKING FOR A PLEASANT THANKSGIVING DAY MOST
AREAS. OTHER LOWER ELEVATIONS WILL HAVE HIGHS IN THE 40S WITH 30S TO
LOW 40S IN THE FAR WEST VALLEYS. HIGHS WILL ONLY BE IN THE 40S
ACROSS THE EASTERN BIG HORN BASIN THU/FRI WITH FRESH SNOW COVER IN
PLACE THERE. ONLY ISOLATED SHOWERS ARE EXPECTED IN THE NW MTNS WITH
THE CONTINUED NW TO WEST FLOW DURING THIS TIME FRAME. THEN BY
SATURDAY...SNOWFALL IN THE WEST WITH SOME RAIN MIXED IN WITH THE
SNOW IN THE WESTERN VALLEYS...IS EXPECTED AS THE NEXT NORTHERN
PACIFIC TROUGH BEING DRIVEN BY THE SPINNING POLAR VORTEX SWINGS BY
JUST TO OUR NORTH WITH NORTHERN WY BEING CONSIDERABLY COLDER THEN
CENTRAL AND SOUTHERN WY ON SUNDAY. THE SNOW WILL CONTINUE ON
SATURDAY NIGHT IN THE WEST. DRYING IS EXPECTED SUNDAY. TEMPS WILL
WARM UP MONDAY BEFORE COOLING EVERYWHERE TUE BUT NOT TO THE EXTENT
THAT IS DOES SUNDAY IN THE NORTH AS THE NEXT SPLITTING PACIFIC TROUGH
APPROACHES FROM THE WEST AND WE CAPTURE THE NORTHERN STREAM ENERGY.
THE GFS AND THE EURO ARE IN FAIRLY GOOD AGREEMENT WITH THIS. KEPT
MORE SNOW IN THE FORECAST FOR WESTERN WY MONDAY NIGHT AND TUESDAY
WITH THIS NEXT TROUGH.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE THROUGH 00Z THURSDAY.  TO THE SOUTH VFR
CONDITIONS ARE EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN
NATRONA COUNTIES UNTIL 02Z THEN IFR/MVFR CONDITIONS WILL SPREAD
SOUTH BEHIND THE COLD FRONT UP TO THE CONTINENTAL DIVIDE BY 05Z.
STRONG WEST WINDS 30 TO 40 KTS WITH GUSTS TO 60KTS ARE EXPECTED
ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS
WILL SHIFT TO THE NORTH AS A COLD FRONT MOVES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 15Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 15Z TO 18Z. STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z THEN WILL GRADUALLY DIMINISH.

&&

.FIRE WEATHER...

COLD SNOWY WINTER WEATHER WITH STRONG WINDS AND LOW MIXING HEIGHTS
WILL PERSIST. VARIOUS WARNINGS AND ADVISORIES ARE IN EFFECT TONIGHT
FOR WIND AND SNOW. HEAVY SNOW ACCUMULATION IS POSSIBLE IN THE NORTHERN
AND WESTERN MOUNTAINS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER








000
FXUS63 KUNR 252108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
208 PM MST TUE NOV 25 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014

THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.

THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.

ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.

THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.

THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.

WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014

SNOW AND A RAIN/SNOW MIX WILL CONTINUE ACROSS MUCH OF THE
REGION...BRINGING WIDESPREAD MVFR/IFR CONDITIONS INTO TONIGHT.
SOME LIFR CONDITIONS EXPECTED AROUND THE NRN BLKHLS. LOW CLOUDS
WILL HANG AROUND THROUGH WEDNESDAY MORNING. NORTHWEST WINDS WILL
BE GUSTY THIS AFTERNOON AND INTO TONIGHT...GRADUALLY DIMINISHING
AFTER MIDNIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
     SDZ014-025-026-031-032-043-072-073.

     WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...POJORLIE






000
FXUS65 KRIW 252018
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
118 PM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

UPGRADED WINTER WEATHER ADVISORIES TO WINTER STORM WARNINGS ACROSS
THE MOUNTAINS AND WESTERN VALLEYS. ISSUED WINTER STORM WARING FOR
BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE REST OF THE
BIGHORN BASIN AND JOHNSON COUNTY. ALSO ISSUED WINTER WEATHER ADVISORY
FOR THE UPPER GREEN RIVER BASIN. REPORTS OF 6 TO 7 INCHES IN STAR
VALLEY AND 4 TO 6 INCHES IN BIGHORN COUNTY TODAY.

ISSUED HIGH WIND WARNING FOR UPPER WIND RIVER CANYON...SOUTHERN
LINCOLN...AND SWEETWATER COUNTIES FROM 11 AM MST THROUGH 11 PM MST THIS
EVENING FOR 35 TO 45 MPH WINDS GUSTING TO 60 MPH.

INCREASED SNOWFALL AND CHANCE OF PRECIPITATION ACROSS THE
MOUNTAINS AND NORTH. SNOWFALL OF 1 TO 3 INCHES IN THE LOWER
ELEVATIONS OF THE NORTH. COLD FRONT COMING SOUTH AND WINDS HAVE
DECREASED ACROSS THE NORTH.

UPDATE... UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER
ADVISORY MIX THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW
AND WITH TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN
SNOW FOR QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS
AFTERNOON ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9
HOURS OF MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE
LOWER ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SNOWFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE.  TO THE SOUTH VFR CONDITIONS ARE
EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN NATRONA COUNTIES
UNTIL 00Z THEN IFR/MVFR CONDITIONS WILL SPREAD SOUTH BEHIND THE
COLD FRONT UP TO THE CONTINENTAL DIVIDE.  STRONG WEST WINDS 30 TO
40 KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS WILL SHIFT TO THE NORTH
AS A COLD FRONT MOVES SOUTH FROM MONTANA.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 12Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 12Z TO 18Z.  STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z.

FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS







000
FXUS65 KRIW 252018
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
118 PM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

UPGRADED WINTER WEATHER ADVISORIES TO WINTER STORM WARNINGS ACROSS
THE MOUNTAINS AND WESTERN VALLEYS. ISSUED WINTER STORM WARING FOR
BIGHORN COUNTY WITH WINTER WEATHER ADVISORIES FOR THE REST OF THE
BIGHORN BASIN AND JOHNSON COUNTY. ALSO ISSUED WINTER WEATHER ADVISORY
FOR THE UPPER GREEN RIVER BASIN. REPORTS OF 6 TO 7 INCHES IN STAR
VALLEY AND 4 TO 6 INCHES IN BIGHORN COUNTY TODAY.

ISSUED HIGH WIND WARNING FOR UPPER WIND RIVER CANYON...SOUTHERN
LINCOLN...AND SWEETWATER COUNTIES FROM 11 AM MST THROUGH 11 PM MST THIS
EVENING FOR 35 TO 45 MPH WINDS GUSTING TO 60 MPH.

INCREASED SNOWFALL AND CHANCE OF PRECIPITATION ACROSS THE
MOUNTAINS AND NORTH. SNOWFALL OF 1 TO 3 INCHES IN THE LOWER
ELEVATIONS OF THE NORTH. COLD FRONT COMING SOUTH AND WINDS HAVE
DECREASED ACROSS THE NORTH.

UPDATE... UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER
ADVISORY MIX THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW
AND WITH TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN
SNOW FOR QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS
AFTERNOON ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9
HOURS OF MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE
LOWER ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SNOWFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE.  TO THE SOUTH VFR CONDITIONS ARE
EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN NATRONA COUNTIES
UNTIL 00Z THEN IFR/MVFR CONDITIONS WILL SPREAD SOUTH BEHIND THE
COLD FRONT UP TO THE CONTINENTAL DIVIDE.  STRONG WEST WINDS 30 TO
40 KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS WILL SHIFT TO THE NORTH
AS A COLD FRONT MOVES SOUTH FROM MONTANA.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 12Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 12Z TO 18Z.  STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z.

FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ003-005>007-010-011-025.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY
WYZ001-002-004-008-009-012>015-024.

WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT WYZ023.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS








000
FXUS65 KCYS 251944
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1244 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 1244 PM MST TUE NOV 25 2014

STRONG WINDS HAVE DEVELOPED THIS MORNING AS EXPECTED ACROSS
PORTIONS OF SOUTHEAST WYOMING. HIGHEST WINDS RECORDED SO FAR
OCCURRED IN THE ARLINGTON AREA BETWEEN 4 AND 8 AM...WITH GUSTS
RANGING FROM 65 TO 80 MPH. 55 TO 65 MPH GUSTS WERE COMMON
ELSEWHERE WITHIN THE WARNING. ALSO NOTICED KSAA APPROACHING HIGH
WIND CRITERIA...SO ADDED IN THE UPPER NORTH PLATTE RIVER VALLEY TO
THE HIGH WIND WARNING. WINDS HAVE SETTLED A BIT SINCE EARLIER
ON WITH SPEEDS AVERAGING MORE 55 TO 65 MPH. SHOULD SEE THESE
SPEEDS CONTINUE THROUGH THE EVENING AS FULL MIXING POTENTIAL IS
REALIZED...WITH PERHAPS A SLIGHT BUMP UP IN SPEEDS EARLY THIS
EVENING AS THE COLD FRONT APPROACHES FROM THE NORTH. THE COLD
FRONT WILL PASS SOUTH THROUGH THE PLAINS BY 03Z AND WILL STALL
ALONG THE LARAMIE RANGE...RELAXING THE GRADIENT SUFFICIENTLY TO
DIMINISH WINDS ACROSS THE AREA. HOWEVER...THINK THE LULL IN SPEEDS
WILL BE BRIEF OUT AT ARLINGTON AND EXPECT SPEEDS TO INCREASE ONCE
AGAIN AS SUNRISE APPROACHES. IN ADDITION...THE FRONT WILL SHIFT
EAST THROUGH THE MORNING AND WILL RESTRENGTHEN THE LLVL PRESSURE
GRADIENT...WHICH IS FAVORABLE FOR GAP WINDS TO REDEVELOP IN THIS
AREA. SO WENT AHEAD AND EXTENDED THE HIGH WIND WARNING FOR THE
ARLINGTON AREA THROUGH TOMORROW AFTERNOON. MAY HAVE TO REVISIT
WIND HIGHLIGHTS FOR THE SOUTHERN LARAMIE RANGE AND BORDEAUX AS
WELL...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT HIGH WINDS WILL BE
REALIZED AT THIS TIME.

SURFACE AND RADAR TRENDS OVER THE PAST FEW HOURS OVER NORTHERN
WYOMING SYNC UP FAIRLY WELL WITH GUIDANCE REGARDING SNOW
POTENTIAL FOR THIS EVENING AND OVERNIGHT PERIOD ACROSS THE EASTERN
PLAINS. BASED ON CONSISTENT PROGS FOR FRONTOGENESIS AND NEGATIVE
EPV ABOVE THE FRONTOGENESIS BAND...UPSLOPE FLOW BEHIND THE
FRONT...AND SUFFICIENT MOISTURE LINING UP NW-SE FROM THE SOUTHERN
LARAMIE RANGE TO EASTERN LARAMIE COUNTY...FEEL CONFIDENT IN THE
POTENTIAL FOR NW-SE ORIENTED SNOW BANDS TO DEVELOP AFTER AROUND
02Z THIS EVENING AND PERSISTING OVERNIGHT IN THIS AREA. INITIAL
DEEP OMEGA AS THE FRONTOGENESIS BAND INTENSIFIES WILL WANE
OVERNIGHT AS SUBSIDENCE IN THE RFQ OF THE UPPER JET MOVES
OVERHEAD...SO WILL LIMIT SNOW ACCUMULATIONS TO 2 TO 5 INCHES ON
AVERAGE WITH LOCALLY HIGHER AMOUNTS DEPENDING ON WHERE EXACTLY THE
BAND SETTLES. THUS...WENT AHEAD WITH A WINTER WEATHER ADVISORY FOR
SOUTHERN PLATTE COUNTY...CENTRAL AND EASTERN LARAMIE COUNTIES.
CURRENT PROGS EVENTUALLY SETTLE THE SNOW BAND SOUTH OF GOSHEN
COUNTY SO WILL KEEP IT OUT OF THE ADVISORY FOR NOW.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1029 AM MST TUE NOV 25 2014

STRONG WEST WINDS WILL CONTINUE TO BE THE MAIN AVIATION HAZARD
ACROSS SOUTHEAST WYOMING THROUGH THE AFTERNOON. WINDS COULD GUST
AS HIGH AS 55 KTS OVER THE NEXT SEVERAL HOURS WITH MOUNTAIN WAVE
ACTIVITY RESULTING IN POTENTIALLY SEVERE LOW-LEVEL TURBULENCE. A
HIGH WIND WARNING IS IN EFFECT. AREAS OF BLOWING SNOW WILL ALSO BE
POSSIBLE THROUGH THE DAY. SNOW WILL DEVELOP AFTER 23Z AND CONTINUE
THROUGH THE NIGHT...MAINLY ALONG AND SOUTHWEST OF A LINE FROM DGW
TO BFF. IFR VSBYS CAN BE EXPECTED IN -SN AND BLSN.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-116-117.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM MST
     WEDNESDAY FOR WYZ106-107-117>119.

     HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR WYZ107-113-115-
     118-119.

NE...NONE.
&&

$$

UPDATE...RJM
SHORT TERM...CAH
LONG TERM...ZF
AVIATION...CLH
FIRE WEATHER...CAH



000
FXUS65 KCYS 251944
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1244 PM MST TUE NOV 25 2014

.UPDATE...
ISSUED AT 1244 PM MST TUE NOV 25 2014

STRONG WINDS HAVE DEVELOPED THIS MORNING AS EXPECTED ACROSS
PORTIONS OF SOUTHEAST WYOMING. HIGHEST WINDS RECORDED SO FAR
OCCURRED IN THE ARLINGTON AREA BETWEEN 4 AND 8 AM...WITH GUSTS
RANGING FROM 65 TO 80 MPH. 55 TO 65 MPH GUSTS WERE COMMON
ELSEWHERE WITHIN THE WARNING. ALSO NOTICED KSAA APPROACHING HIGH
WIND CRITERIA...SO ADDED IN THE UPPER NORTH PLATTE RIVER VALLEY TO
THE HIGH WIND WARNING. WINDS HAVE SETTLED A BIT SINCE EARLIER
ON WITH SPEEDS AVERAGING MORE 55 TO 65 MPH. SHOULD SEE THESE
SPEEDS CONTINUE THROUGH THE EVENING AS FULL MIXING POTENTIAL IS
REALIZED...WITH PERHAPS A SLIGHT BUMP UP IN SPEEDS EARLY THIS
EVENING AS THE COLD FRONT APPROACHES FROM THE NORTH. THE COLD
FRONT WILL PASS SOUTH THROUGH THE PLAINS BY 03Z AND WILL STALL
ALONG THE LARAMIE RANGE...RELAXING THE GRADIENT SUFFICIENTLY TO
DIMINISH WINDS ACROSS THE AREA. HOWEVER...THINK THE LULL IN SPEEDS
WILL BE BRIEF OUT AT ARLINGTON AND EXPECT SPEEDS TO INCREASE ONCE
AGAIN AS SUNRISE APPROACHES. IN ADDITION...THE FRONT WILL SHIFT
EAST THROUGH THE MORNING AND WILL RESTRENGTHEN THE LLVL PRESSURE
GRADIENT...WHICH IS FAVORABLE FOR GAP WINDS TO REDEVELOP IN THIS
AREA. SO WENT AHEAD AND EXTENDED THE HIGH WIND WARNING FOR THE
ARLINGTON AREA THROUGH TOMORROW AFTERNOON. MAY HAVE TO REVISIT
WIND HIGHLIGHTS FOR THE SOUTHERN LARAMIE RANGE AND BORDEAUX AS
WELL...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT HIGH WINDS WILL BE
REALIZED AT THIS TIME.

SURFACE AND RADAR TRENDS OVER THE PAST FEW HOURS OVER NORTHERN
WYOMING SYNC UP FAIRLY WELL WITH GUIDANCE REGARDING SNOW
POTENTIAL FOR THIS EVENING AND OVERNIGHT PERIOD ACROSS THE EASTERN
PLAINS. BASED ON CONSISTENT PROGS FOR FRONTOGENESIS AND NEGATIVE
EPV ABOVE THE FRONTOGENESIS BAND...UPSLOPE FLOW BEHIND THE
FRONT...AND SUFFICIENT MOISTURE LINING UP NW-SE FROM THE SOUTHERN
LARAMIE RANGE TO EASTERN LARAMIE COUNTY...FEEL CONFIDENT IN THE
POTENTIAL FOR NW-SE ORIENTED SNOW BANDS TO DEVELOP AFTER AROUND
02Z THIS EVENING AND PERSISTING OVERNIGHT IN THIS AREA. INITIAL
DEEP OMEGA AS THE FRONTOGENESIS BAND INTENSIFIES WILL WANE
OVERNIGHT AS SUBSIDENCE IN THE RFQ OF THE UPPER JET MOVES
OVERHEAD...SO WILL LIMIT SNOW ACCUMULATIONS TO 2 TO 5 INCHES ON
AVERAGE WITH LOCALLY HIGHER AMOUNTS DEPENDING ON WHERE EXACTLY THE
BAND SETTLES. THUS...WENT AHEAD WITH A WINTER WEATHER ADVISORY FOR
SOUTHERN PLATTE COUNTY...CENTRAL AND EASTERN LARAMIE COUNTIES.
CURRENT PROGS EVENTUALLY SETTLE THE SNOW BAND SOUTH OF GOSHEN
COUNTY SO WILL KEEP IT OUT OF THE ADVISORY FOR NOW.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1029 AM MST TUE NOV 25 2014

STRONG WEST WINDS WILL CONTINUE TO BE THE MAIN AVIATION HAZARD
ACROSS SOUTHEAST WYOMING THROUGH THE AFTERNOON. WINDS COULD GUST
AS HIGH AS 55 KTS OVER THE NEXT SEVERAL HOURS WITH MOUNTAIN WAVE
ACTIVITY RESULTING IN POTENTIALLY SEVERE LOW-LEVEL TURBULENCE. A
HIGH WIND WARNING IS IN EFFECT. AREAS OF BLOWING SNOW WILL ALSO BE
POSSIBLE THROUGH THE DAY. SNOW WILL DEVELOP AFTER 23Z AND CONTINUE
THROUGH THE NIGHT...MAINLY ALONG AND SOUTHWEST OF A LINE FROM DGW
TO BFF. IFR VSBYS CAN BE EXPECTED IN -SN AND BLSN.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-116-117.

     HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.

     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM MST
     WEDNESDAY FOR WYZ106-107-117>119.

     HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR WYZ107-113-115-
     118-119.

NE...NONE.
&&

$$

UPDATE...RJM
SHORT TERM...CAH
LONG TERM...ZF
AVIATION...CLH
FIRE WEATHER...CAH




000
FXUS65 KRIW 251756
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1056 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

ISSUED HIGH WIND WARNING FOR UPPER WIND RIVER CANYON...SOUTHERN
LINCOLN...AND SWEETWATER COUNTIES FROM 11 AM MST THROUGH 11 PM MST THIS
EVENING FOR 35 TO 45 MPH WINDS GUSTING TO 60 MPH.

INCREASED SNOWFALL AND CHANCE OF PRECIPITATION ACROSS THE
MOUNTAINS AND NORTH. SNOWFALL OF 1 TO 3 INCHES IN THE LOWER
ELEVATIONS OF THE NORTH. COLD FRONT COMING SOUTH AND WINDS HAVE
DECREASED ACROSS THE NORTH.

UPDATE... UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER
ADVISORY MIX THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW
AND WITH TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN
SNOW FOR QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS
AFTERNOON ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9
HOURS OF MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE
LOWER ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SNOWFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE.  TO THE SOUTH VFR CONDITIONS ARE
EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN NATRONA COUNTIES
UNTIL 00Z THEN IFR/MVFR CONDITIONS WILL SPREAD SOUTH BEHIND THE
COLD FRONT UP TO THE CONTINENTAL DIVIDE.  STRONG WEST WINDS 30 TO
40 KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS WILL SHIFT TO THE NORTH
AS A COLD FRONT MOVES SOUTH FROM MONTANA.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 12Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 12Z TO 18Z.  STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z.

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ023.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS






000
FXUS65 KRIW 251756
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1056 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

ISSUED HIGH WIND WARNING FOR UPPER WIND RIVER CANYON...SOUTHERN
LINCOLN...AND SWEETWATER COUNTIES FROM 11 AM MST THROUGH 11 PM MST THIS
EVENING FOR 35 TO 45 MPH WINDS GUSTING TO 60 MPH.

INCREASED SNOWFALL AND CHANCE OF PRECIPITATION ACROSS THE
MOUNTAINS AND NORTH. SNOWFALL OF 1 TO 3 INCHES IN THE LOWER
ELEVATIONS OF THE NORTH. COLD FRONT COMING SOUTH AND WINDS HAVE
DECREASED ACROSS THE NORTH.

UPDATE... UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER
ADVISORY MIX THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW
AND WITH TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN
SNOW FOR QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS
AFTERNOON ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9
HOURS OF MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE
LOWER ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SNOWFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE.  TO THE SOUTH VFR CONDITIONS ARE
EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN NATRONA COUNTIES
UNTIL 00Z THEN IFR/MVFR CONDITIONS WILL SPREAD SOUTH BEHIND THE
COLD FRONT UP TO THE CONTINENTAL DIVIDE.  STRONG WEST WINDS 30 TO
40 KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z. WINDS WILL SHIFT TO THE NORTH
AS A COLD FRONT MOVES SOUTH FROM MONTANA.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 12Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 12Z TO 18Z.  STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z.

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ023.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS







000
FXUS63 KUNR 251716
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1016 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 254 AM MST TUE NOV 25 2014

MORNING UPPER ANALYSIS SHOWED A TROUGH OVER THE EASTERN HALF OF THE
CONUS WITH A RIDGE OFF THE WEST COAST. A SHORTWAVE TROUGH
CURRENTLY LOCATED OVER MONTANA WILL CROSS THE DAKOTAS TODAY INTO
TONIGHT. A SFC LOW WAS LOCATED OVER ALBERTA WITH DEEPENING LEE
SIDE SFC TROUGH EAST OF THE NRN ROCKIES.

MID-HIGH LEVEL WAA AND MOISTURE WILL INCREASE AHEAD OF THE SHORTWAVE
TROUGH THIS MORNING...SPREADING WIDESPREAD CLOUDS AND PRECIPITATION ACROSS
THE AREA. MAINLY SNOW IS EXPECTED THIS MORNING AS THE PRECIP MOVES
IN FROM THE NORTHWEST BUT GIVEN THE WARMING PROFILES THERE MAY BE
A MIX OF RAIN AND SNOW ACROSS MUCH OF THE PLAINS THIS AFTN. UP TO
A COUPLE OF INCHES OF SNOW IS EXPECTED TO FALL ACROSS PARTS OF
NORTHEASTERN WYOMING...BUT WITH SFC TEMPS RISING ABOVE THE
FREEZING MARK LATER THIS MORNING...SNOW ACCUMULATIONS ON THE ROADS
THERE MAY BE LIMITED. UP TO 3 INCHES OF SNOW IS EXPECTED ACROSS
THE NORTHWESTERN PARTS OF THE BLACK HILLS TODAY WITH LOCALLY
HIGHER AMOUNTS POSSIBLE OVER THE HIGHEST ELEVATIONS.

THE SFC LOW WILL DROP SOUTHEASTWARD FROM WESTERN NORTH DAKOTA AROUND
MID-DAY INTO EASTERN SOUTH DAKOTA THIS EVENING. NORTHWESTERLY WINDS
WILL BECOME VERY WINDY ACROSS NORTHWESTERN SOUTH DAKOTA THIS
AFTERNOON AS THE LOW DROPS SOUTHWARD AND TIGHTENS THE SFC PRESSURE
GRADIENT. THE ARRIVAL OF THE COLDER AIR LOOKS LIKE IT WILL BE
DELAYED UNTIL THIS EVENING BUT THEN GUSTY WINDS WILL SPREAD
SOUTHWARD ACROSS THE AREA AS THE COOLER AIR MOVES INTO THE AREA.
AT THIS TIME IT LOOKS LIKE MOST OF THE SNOW WILL BE OVER BY THE
TIME THE WIND PICKS UP OVER NORTHWESTERN SOUTH DAKOTA THIS AFTN
AND DUE TO THE WARM TEMPS BLOWING SNOW SHOULDN/T BE MUCH OF A
PROBLEM. THEREFORE HAVE DECIDED TO ISSUE A WIND ADVISORY FROM LATE
THIS AFTERNOON INTO TONIGHT. IF THE PRECIPITATION LINGERS LONGER
OR THE SNOW IS A BIT HEAVIER OVER NWRN SD WHEN THE WIND INCREASES
THEN THE WIND ADVISORY THERE MAY NEED TO BE CHANGED TO A WINTER
WEATHER ADVISORY UNTIL THE SNOW TAPERS OFF. 06 NAM SHOWS 850MB
WINDS INCREASING TO 45-50KTS BEHIND THE FRONT THIS AFT/EVE.
HOWEVER THERE ISN/T A VERY STRONG TEMPERATURE CONTRAST ALONG OR
DIRECTLY BEHIND THE FRONTAL BOUNDARY. THIS IS EXPECTED TO LIMIT
MIXING AND THE POTENTIAL MOMENTUM TRANSFER TO THE SFC SO IT LOOKS
LIKE THE WIND ADVISORY WILL BE ADEQUATE FOR THE SITUATION.

THE PRECIPITATION WILL DIMINISH THIS EVENING ALTHOUGH FLURRIES OR
LIGHT SNOW ARE POSSIBLE THROUGH THE NIGHT AS THE COLDER AIR
CONTINUES TO FLOW INTO THE REGION. THERE IS A ANOTHER CHANCE OF
LIGHT SNOW ON WEDNESDAY AS A NE-SW ORIENTED REGION OF MID LEVEL
FRONTOGENESIS WORKS EASTWARD ACROSS THE FORECAST AREA AND RELATIVELY
WARMER AIR ALOFT OVER RIDES THE COLDER AIR AT THE SFC.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 254 AM MST TUE NOV 25 2014

LOW AMPLITUDE RIDGING WILL DEVELOP THANKSGIVING DAY
ACROSS THE ROCKIES INTO THE NORTHERN PLAINS. STRONG WARM AIR
ADVECTION WILL DEVELOP WEDNESDAY NIGHT INTO THURSDAY PUSHING THE
WARM FRONT NE INTO THE CENTRAL DAKOTAS. THE RESULT WILL BE DRY AND
MUCH WARMER WEATHER FOR THANKSGIVING AND FRIDAY. CNTRL SD WILL REACH
THE 30S AS THE FRONTAL BOUNDARY GRADUALLY PUSHES THROUGH DURING THE
DAY. FARTHER WEST INTO THE WARM SECTOR...HIGHS WILL LIKELY REACH
WELL INTO THE 40S TO POSSIBLY LOWER 50S. ON FRIDAY...HIGHS WILL
REACH THE UPPER 40S TO UPPER 50S.

THE NEXT COLD FRONT WILL CROSS THE AREA SATURDAY AS A SHALLOW TROUGH
CROSSES SRN CANADA INTO MT/ND. IF THIS SOLUTION PANS OUT...TEMPS
WILL BE DROPPING THROUGH THE DAY SATURDAY INTO THE TEENS AND
20S...AND THEN SINGLE DIGITS OVERNIGHT. WELL BELOW AVERAGE TEMPS ARE
EXPECTED AGAIN SUNDAY...BUT THEN MODELS SHOW WARMER AIR ADVECTING
BACK IN EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
AT THIS TIME IT APPEARS SOME SNOW WILL ACCOMPANY THE FRONTAL
PASSAGE/CAA SATURDAY AND SUNDAY...BUT IT APPEARS QPF WILL BE MINIMAL.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 1013 AM MST TUE NOV 25 2014

SNOW AND A RAIN/SNOW MIX WILL SPREAD ACROSS THE REGION
TODAY...BRINGING WIDESPREAD MVFR/IFR CONDITIONS. SOME LIFR
CONDITIONS EXPECTED AROUND THE NRN BLKHLS. LOW CLOUDS WILL HANG
AROUND THROUGH WEDNESDAY MORNING. NORTHWEST WINDS WILL BE GUSTY THIS
AFTERNOON AND INTO TONIGHT...GRADUALLY DIMINISHING AFTER MIDNIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
     SDZ014-025-026-031-032-043-072-073.

     WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST WEDNESDAY FOR
     SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE






000
FXUS63 KUNR 251716
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1016 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 254 AM MST TUE NOV 25 2014

MORNING UPPER ANALYSIS SHOWED A TROUGH OVER THE EASTERN HALF OF THE
CONUS WITH A RIDGE OFF THE WEST COAST. A SHORTWAVE TROUGH
CURRENTLY LOCATED OVER MONTANA WILL CROSS THE DAKOTAS TODAY INTO
TONIGHT. A SFC LOW WAS LOCATED OVER ALBERTA WITH DEEPENING LEE
SIDE SFC TROUGH EAST OF THE NRN ROCKIES.

MID-HIGH LEVEL WAA AND MOISTURE WILL INCREASE AHEAD OF THE SHORTWAVE
TROUGH THIS MORNING...SPREADING WIDESPREAD CLOUDS AND PRECIPITATION ACROSS
THE AREA. MAINLY SNOW IS EXPECTED THIS MORNING AS THE PRECIP MOVES
IN FROM THE NORTHWEST BUT GIVEN THE WARMING PROFILES THERE MAY BE
A MIX OF RAIN AND SNOW ACROSS MUCH OF THE PLAINS THIS AFTN. UP TO
A COUPLE OF INCHES OF SNOW IS EXPECTED TO FALL ACROSS PARTS OF
NORTHEASTERN WYOMING...BUT WITH SFC TEMPS RISING ABOVE THE
FREEZING MARK LATER THIS MORNING...SNOW ACCUMULATIONS ON THE ROADS
THERE MAY BE LIMITED. UP TO 3 INCHES OF SNOW IS EXPECTED ACROSS
THE NORTHWESTERN PARTS OF THE BLACK HILLS TODAY WITH LOCALLY
HIGHER AMOUNTS POSSIBLE OVER THE HIGHEST ELEVATIONS.

THE SFC LOW WILL DROP SOUTHEASTWARD FROM WESTERN NORTH DAKOTA AROUND
MID-DAY INTO EASTERN SOUTH DAKOTA THIS EVENING. NORTHWESTERLY WINDS
WILL BECOME VERY WINDY ACROSS NORTHWESTERN SOUTH DAKOTA THIS
AFTERNOON AS THE LOW DROPS SOUTHWARD AND TIGHTENS THE SFC PRESSURE
GRADIENT. THE ARRIVAL OF THE COLDER AIR LOOKS LIKE IT WILL BE
DELAYED UNTIL THIS EVENING BUT THEN GUSTY WINDS WILL SPREAD
SOUTHWARD ACROSS THE AREA AS THE COOLER AIR MOVES INTO THE AREA.
AT THIS TIME IT LOOKS LIKE MOST OF THE SNOW WILL BE OVER BY THE
TIME THE WIND PICKS UP OVER NORTHWESTERN SOUTH DAKOTA THIS AFTN
AND DUE TO THE WARM TEMPS BLOWING SNOW SHOULDN/T BE MUCH OF A
PROBLEM. THEREFORE HAVE DECIDED TO ISSUE A WIND ADVISORY FROM LATE
THIS AFTERNOON INTO TONIGHT. IF THE PRECIPITATION LINGERS LONGER
OR THE SNOW IS A BIT HEAVIER OVER NWRN SD WHEN THE WIND INCREASES
THEN THE WIND ADVISORY THERE MAY NEED TO BE CHANGED TO A WINTER
WEATHER ADVISORY UNTIL THE SNOW TAPERS OFF. 06 NAM SHOWS 850MB
WINDS INCREASING TO 45-50KTS BEHIND THE FRONT THIS AFT/EVE.
HOWEVER THERE ISN/T A VERY STRONG TEMPERATURE CONTRAST ALONG OR
DIRECTLY BEHIND THE FRONTAL BOUNDARY. THIS IS EXPECTED TO LIMIT
MIXING AND THE POTENTIAL MOMENTUM TRANSFER TO THE SFC SO IT LOOKS
LIKE THE WIND ADVISORY WILL BE ADEQUATE FOR THE SITUATION.

THE PRECIPITATION WILL DIMINISH THIS EVENING ALTHOUGH FLURRIES OR
LIGHT SNOW ARE POSSIBLE THROUGH THE NIGHT AS THE COLDER AIR
CONTINUES TO FLOW INTO THE REGION. THERE IS A ANOTHER CHANCE OF
LIGHT SNOW ON WEDNESDAY AS A NE-SW ORIENTED REGION OF MID LEVEL
FRONTOGENESIS WORKS EASTWARD ACROSS THE FORECAST AREA AND RELATIVELY
WARMER AIR ALOFT OVER RIDES THE COLDER AIR AT THE SFC.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 254 AM MST TUE NOV 25 2014

LOW AMPLITUDE RIDGING WILL DEVELOP THANKSGIVING DAY
ACROSS THE ROCKIES INTO THE NORTHERN PLAINS. STRONG WARM AIR
ADVECTION WILL DEVELOP WEDNESDAY NIGHT INTO THURSDAY PUSHING THE
WARM FRONT NE INTO THE CENTRAL DAKOTAS. THE RESULT WILL BE DRY AND
MUCH WARMER WEATHER FOR THANKSGIVING AND FRIDAY. CNTRL SD WILL REACH
THE 30S AS THE FRONTAL BOUNDARY GRADUALLY PUSHES THROUGH DURING THE
DAY. FARTHER WEST INTO THE WARM SECTOR...HIGHS WILL LIKELY REACH
WELL INTO THE 40S TO POSSIBLY LOWER 50S. ON FRIDAY...HIGHS WILL
REACH THE UPPER 40S TO UPPER 50S.

THE NEXT COLD FRONT WILL CROSS THE AREA SATURDAY AS A SHALLOW TROUGH
CROSSES SRN CANADA INTO MT/ND. IF THIS SOLUTION PANS OUT...TEMPS
WILL BE DROPPING THROUGH THE DAY SATURDAY INTO THE TEENS AND
20S...AND THEN SINGLE DIGITS OVERNIGHT. WELL BELOW AVERAGE TEMPS ARE
EXPECTED AGAIN SUNDAY...BUT THEN MODELS SHOW WARMER AIR ADVECTING
BACK IN EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
AT THIS TIME IT APPEARS SOME SNOW WILL ACCOMPANY THE FRONTAL
PASSAGE/CAA SATURDAY AND SUNDAY...BUT IT APPEARS QPF WILL BE MINIMAL.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 1013 AM MST TUE NOV 25 2014

SNOW AND A RAIN/SNOW MIX WILL SPREAD ACROSS THE REGION
TODAY...BRINGING WIDESPREAD MVFR/IFR CONDITIONS. SOME LIFR
CONDITIONS EXPECTED AROUND THE NRN BLKHLS. LOW CLOUDS WILL HANG
AROUND THROUGH WEDNESDAY MORNING. NORTHWEST WINDS WILL BE GUSTY THIS
AFTERNOON AND INTO TONIGHT...GRADUALLY DIMINISHING AFTER MIDNIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
     SDZ014-025-026-031-032-043-072-073.

     WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST WEDNESDAY FOR
     SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE







000
FXUS65 KRIW 251626
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
926 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

ISSUED HIGH WIND WARNING FOR UPPER WIND RIVER CANYON...SOUTHERN
LINCOLN...AND SWEETWATER COUNTIES FROM 11 AM MST THROUGH 11 PM MST THIS
EVENING FOR 35 TO 35 MPH WINDS GUSTING TO 60 MPH.


UPDATE... UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER
ADVISORY MIX THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW
AND WITH TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN
SNOW FOR QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS
AFTERNOON ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9
HOURS OF MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE
LOWER ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SNOWFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

OVER THE MOUNTAINS AND NORTH IFR TO MVFR CEILINGS AND VISIBILITIES
REDUCED IN SNOW AND BLOWING SNOW WILL BE WIDESPREAD THROUGH 12Z
WEDNESDAY...THEN DECREASE...TO THE SOUTH VFR CONDITIONS ARE
EXPECTED IN THE WIND RIVER BASIN AND SOUTHERN NATRONA COUNTIES.
STRONG WEST WINDS 30 TO 40 KTS WITH GUSTS TO 60KTS ARE EXPECTED
ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS UNTIL 06Z.  WINDS
WILL SHIFT TO THE NORTH AS A COLD FRONT MOVES SOUTH FROM MONTANA.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

IFR TO LOCAL MVFR CEILINGS AND VISIBILITIES REDUCED IN SNOW AND
BLOWING SNOW WILL BE ACROSS THE EAST THROUGH 12Z WEDNESDAY WITH
GRADUAL IMPROVEMENT FROM 12Z TO 18Z.  STRONG WEST WINDS 30 TO 40
KTS WITH GUSTS TO 60KTS ARE EXPECTED ALONG AND NEAR THE EAST
SLOPES OF THE MOUNTAINS UNTIL 06Z.

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING WYZ016-027>030.

WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ023.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...C.BAKER
FIRE WEATHER...HATTINGS








000
FXUS65 KCYS 251204
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
504 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 458 AM MST TUE NOV 25 2014

MAIN AVIATION CONCERN THROUGH THE AFTERNOON WILL BE THE STRONG
WESTERLY WINDS ACROSS SOUTHEAST WY. EXPECT WINDS TO INCREASE BY
MID-MORNING WITH GUSTS TO 40-45 KTS THROUGH THE AFTERNOON. WINDS
WILL BE WEAKER OVER THE NEBRASKA PANHANDLE. THE WINDS WILL BEGIN
TO SUBSIDE AFTER 00Z BUT REMAIN BREEZY THROUGH THE REMAINDER OF
THE TAF PERIOD. SNOW WILL BECOME LIKELY BY LATE EVENING AT THE WY
SITES WITH REDUCED VISIBILITIES AND IFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.
&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...CAH



000
FXUS65 KCYS 251204
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
504 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 458 AM MST TUE NOV 25 2014

MAIN AVIATION CONCERN THROUGH THE AFTERNOON WILL BE THE STRONG
WESTERLY WINDS ACROSS SOUTHEAST WY. EXPECT WINDS TO INCREASE BY
MID-MORNING WITH GUSTS TO 40-45 KTS THROUGH THE AFTERNOON. WINDS
WILL BE WEAKER OVER THE NEBRASKA PANHANDLE. THE WINDS WILL BEGIN
TO SUBSIDE AFTER 00Z BUT REMAIN BREEZY THROUGH THE REMAINDER OF
THE TAF PERIOD. SNOW WILL BECOME LIKELY BY LATE EVENING AT THE WY
SITES WITH REDUCED VISIBILITIES AND IFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.
&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...CAH



000
FXUS65 KCYS 251204
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
504 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 458 AM MST TUE NOV 25 2014

MAIN AVIATION CONCERN THROUGH THE AFTERNOON WILL BE THE STRONG
WESTERLY WINDS ACROSS SOUTHEAST WY. EXPECT WINDS TO INCREASE BY
MID-MORNING WITH GUSTS TO 40-45 KTS THROUGH THE AFTERNOON. WINDS
WILL BE WEAKER OVER THE NEBRASKA PANHANDLE. THE WINDS WILL BEGIN
TO SUBSIDE AFTER 00Z BUT REMAIN BREEZY THROUGH THE REMAINDER OF
THE TAF PERIOD. SNOW WILL BECOME LIKELY BY LATE EVENING AT THE WY
SITES WITH REDUCED VISIBILITIES AND IFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.
&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...CAH



000
FXUS65 KCYS 251204
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
504 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTHEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYCLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMIE RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 458 AM MST TUE NOV 25 2014

MAIN AVIATION CONCERN THROUGH THE AFTERNOON WILL BE THE STRONG
WESTERLY WINDS ACROSS SOUTHEAST WY. EXPECT WINDS TO INCREASE BY
MID-MORNING WITH GUSTS TO 40-45 KTS THROUGH THE AFTERNOON. WINDS
WILL BE WEAKER OVER THE NEBRASKA PANHANDLE. THE WINDS WILL BEGIN
TO SUBSIDE AFTER 00Z BUT REMAIN BREEZY THROUGH THE REMAINDER OF
THE TAF PERIOD. SNOW WILL BECOME LIKELY BY LATE EVENING AT THE WY
SITES WITH REDUCED VISIBILITIES AND IFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.
&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...CAH



000
FXUS65 KRIW 251125
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
425 AM MST TUE NOV 25 2014

.UPDATE...
UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER ADVISORY MIX
THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW AND WITH
TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN SNOW FOR
QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS AFTERNOON
ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9 HOURS OF
MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE LOWER
ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SN0WFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

&&

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ023.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

UPDATE...SKRBAC
SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS






000
FXUS65 KRIW 251125
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
425 AM MST TUE NOV 25 2014

.UPDATE...
UPDATE TO ADD THE STAR VALLEY INTO THE WINTER WEATHER ADVISORY MIX
THROUGH 00Z. SNOW COMING DOWN PRETTY HARD RIGHT NOW AND WITH
TEMPERATURES ONLY IN THE LOWER TO MID 20S IT WILL REMAIN SNOW FOR
QUITE A WHILE. COULD TRY AND CHANGE OVER LATER THIS AFTERNOON
ONWARD BUT THEY ARE UNDER A HIGH RISK FOR THE NEXT 6-9 HOURS OF
MORE MODERATE TO HEAVY SNOW. WILL ALSO HAVE TO WATCH THE LOWER
ELEVATIONS UP TO THE JACKSON VALLEY FOR POTENTIAL UPGRADE IF
HEAVIER SNOW PERSISTS AS SN0WFALL RATES AROUND AN INCH PER HOUR
ARE QUITE POSSIBLE FROM NOW THROUGH AT LEAST THE MORNING.

&&

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ023.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

UPDATE...SKRBAC
SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS







000
FXUS65 KCYS 251113
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
413 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMEI RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.

&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...GCC
FIRE WEATHER...CAH




000
FXUS65 KCYS 251113
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
413 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMEI RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.

&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...GCC
FIRE WEATHER...CAH




000
FXUS65 KCYS 251113
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
413 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMEI RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.

&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...GCC
FIRE WEATHER...CAH




000
FXUS65 KCYS 251113
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
413 AM MST TUE NOV 25 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 410 AM MST TUE NOV 25 2014

AN ACTIVE PERIOD TAKING ACROSS THE CWA BEGINNING WITH A PERIOD OF
VERY STRONG WINDS ACROSS SOUTEAST WYOMING TODAY FOLLOWED BY SOME
LIGHT TO MODERATE SNOW TONIGHT. LETS FIRST FOCUS ON HIGH WINDS
TODAY. 10Z SFC ANALYSIS SHOWS LOW 1006MB LOW PRESSURE LOCATED OVR
SW SASKATCHEWAN WITH AN AMPLIFYING PRESSURE TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE. KCAG-KCPR GRADIENT ALREADY AT AROUND 13MB
AT THIS HOUR. WINDS HAVE COME UP IN THE ARLINGTON AREA RIGHT ON
TIME BETWEEN 08-09Z WHERE GUSTS HAVE BEEN HOVERING AROUND 60 MPH.
MEANWHILE AT H3...THE FAVORABLE SUBSIDING RFQ OF 160 KNOT
ANTICYLONIC JET WAS JUST ENTERING WRN ZONES EARLY THIS MORNING.
SUBSIDENCE COMBINED WITH H7 PROGS OF 50-70 KNOTS AND KCAG-KCPR
LLVL HEIGHT GRADIENTS OF 60-90 METERS WILL BE MORE THAN ENOUGH FOR
WIDESPREAD GUSTS OF 60+ MPH GUSTS TODAY. THE ONE LIMITING FACTOR
MAY BE JUST HOW MUCH THICKER CLOUD COVER LESSENS LLVL MIXING.
MORNING SATELLITE PIX SHOWS A THICK SLUG OF MOISTURE DROPPING
SOUTHEAST INTO THE AREA. SUSPECT THAT THE TYPICAL WIND PRONE AREAS
WILL HAVE NO PROBLEM SEEING THESE WINDS. HOWEVER...WOULD NOT BE
SURPRISED IF ERN LARAMIE COUNTY STRUGGLES A BIT TO GET THERE.
ALTHOUGH LLVL GRADIENTS DROP OFF SOMEWHAT TONIGHT...THEY STILL
REMAIN ABOVE 60 METERS THRU MIDDAY WEDNESDAY. WOULD NOT BE
SURPRISED IF THE HIGH WIND WARNING NEEDS TO BE EXTENDED INTO
WEDNESDAY MORNING AT LEAST FOR THE ARLINGTON AREA.

THE OTHER FORECAST FOCUS IS THE POTENTIAL FOR SNOW TODAY MAINLY
WEST OF THE LARAMIE RANGE AND TONIGHT ON THE ERN PLAINS OF SE
WYOMING. THE CULPRIT IS A CLIPPER SYSTEM THAT WAS DIVING SOUTHEAST
OUT OF ALBERTA THIS MORNING AND IS PROGD TO REACH THE DAKOTAS BY
SUNSET. AS IT DOES SO...COLD FRONT WILL DROP SOUTH LATE TODAY AND
BECOME STATIONARY ALONG THE LARAMIE RANGE TONIGHT. AREA OF
NEGATIVE EPV BECOMES CO-LOCATED JUST ABOVE THE LLVL SFC FRONT TO
BECOME FAVORABLE FOR THE DEVELOPMENT OF NW/SE ORIENTED SNOW BAND
TONIGHT. HAVE BOOSTED SNOW CHANCES TO ACCOUNT FOR THE INCREASED
CONFIDENCE IN SNOW BANDING TONIGHT. MOST AREAS OF THE SOUTHEAST
WYOMING PLAINS WILL SEE 1 TO 3 INCHES TONIGHT...WITH LOCALLY UP TO
4 OR 5 INCHES POSSIBLE PENDING WHERE THE SNOW BAND SETS UP...WHICH
MODELS HAVE NOW ACROSS LARAMIE COUNTY. THINK THAT AN ADVISORY WILL
BE NECESSARY WHEREVER THIS BAND SETS UP...BUT WILL LET THE DAY
SHIFT TAKE ONE MORE LOOK AT 12Z DATA BEFORE MAKING THAT CALL.
OTHERWISE...THE HEAVY SNOW WILL CONTINUE INTO THE SNOWY/SIERRA
MADRE RANGES THRU TONIGHT WITH AN ADDL FOOT OF SNOW EXPECTED
THERE. WILL KEEP THE WINTER STORM WARNING GOING AS INHERITED.

A LESS EVENTFUL DAY IN STORE ON WEDNESDAY...THOUGH BREEZY TO LOCALLY
WINDY CONDITIONS WILL CONTINUE WEST OF THE LARAMEI RANGE. COLD
FRONT WILL RETREAT EAST DURING THE DAY...BUT NOT BEFORE AREAS EAST
OF A LUSK TO BRIDGEPORT LINE ONLY REACH THE 30S FOR HIGHS.
ELSEWHERE EXPECT HIGH TEMPERATURES TO REACH THE 40S ON WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 410 AM MST TUE NOV 25 2014

TEMPS WILL BE QUITE WARM FOR LATE NOV FROM THANKSGIVING THROUGH
SATURDAY. A LEE TROUGH WILL PROMOTE GOOD DOWNSLOPE FLOW IN THE
LLVLS AND COMBINE WITH 700MB TEMPS OF 1-3C. MOS GUIDANCE HAS THE
WARMEST TEMPS ON FRI WHEN MANY AREAS TO THE EAST OF THE LARAMIE
RANGE WILL BE IN THE UPPER 50S TO LOW 60S. THE CAG-CPR GRADIENT
WILL REMAIN BETWEEN 50 AND 60 METERS FROM THURS INTO MIDDAY SAT
SO WINDY CONDITIONS WILL PERSIST OVER SOUTHEAST WY AND ESPECIALLY
THE WIND PRONE AREAS. COULD SEE A PROLONGED PERIOD OF TWO DAYS
WHERE PLACES LIKE ARLINGTON WILL BE BOUNCING AROUND HIGH WIND
CRITERIA. SHORTWAVE PUSHES SOUTHWARD TO ALONG THE CANADIAN BORDER
ON SAT WITH A SFC HIGH MOVING INTO MONTANA. HIGHER PRESSURES
ACROSS THE PLAINS WILL EFFECTIVELY END THE HIGH WIND THREAT OVER
SOUTHEAST WY BY LATE SAT.  THE GFS SHOWS A COLD FRONT BACKING
ACROSS THE PLAINS ON SAT NIGHT WHEREAS THE ECMWF IS HAS A STRONGER
FRONTAL PUSH AND ASSOCIATED COLD AIR ADVECTION. WENT WITH ABOUT A
15 DEGREE COOLDOWN FOR SUN...BUT THE COLDER ECMWF WOULD JUSTIFY A
BIGGER DROP. CHANCES FOR PRECIP WILL BE MINIMAL BEHIND THE FRONT
AS UPPER LEVEL SUPPORT IS LACKING. TEMPS WILL LIKELY BEGIN TO
MODERATE ON MON AS A TROUGH AMPLIFIES ALONG THE WEST COAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 410 AM MST TUE NOV 25 2014

MINIMAL FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE. A BREEZY
TO LOCALLY WINDY DAY AHEAD ACROSS THE DISTRICTS TODAY WITH WIND
GUSTS OF 60 TO 70 MPH EXPECTED ACROSS MUCH OF SOUTHEAST WYOMING. A
PERIOD OF SNOW WILL FALL TONIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES EXPECTED ACROSS LOWER ELEVATIONS IN SOUTHEAST WYOMING. THE
SNOWY AND SIERRA MADRE RANGES WILL SEE UP TO ANOTHER FOOT OF SNOW
THROUGH TONIGHT.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM THIS MORNING TO 7 PM MST THIS
     EVENING FOR WYZ107-115-118-119.

NE...NONE.

&&

$$

SHORT TERM...CAH
LONG TERM...ZF
AVIATION...GCC
FIRE WEATHER...CAH




000
FXUS63 KUNR 251031
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
331 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 254 AM MST TUE NOV 25 2014

MORNING UPPER ANALYSIS SHOWED A TROUGH OVER THE EASTERN HALF OF THE
CONUS WITH A RIDGE OFF THE WEST COAST. A SHORTWAVE TROUGH
CURRENTLY LOCATED OVER MONTANA WILL CROSS THE DAKOTAS TODAY INTO
TONIGHT. A SFC LOW WAS LOCATED OVER ALBERTA WITH DEEPENING LEE
SIDE SFC TROUGH EAST OF THE NRN ROCKIES.

MID-HIGH LEVEL WAA AND MOISTURE WILL INCREASE AHEAD OF THE SHORTWAVE
TROUGH THIS MORNING...SPREADING WIDESPREAD CLOUDS AND PRECIPITATION ACROSS
THE AREA. MAINLY SNOW IS EXPECTED THIS MORNING AS THE PRECIP MOVES
IN FROM THE NORTHWEST BUT GIVEN THE WARMING PROFILES THERE MAY BE
A MIX OF RAIN AND SNOW ACROSS MUCH OF THE PLAINS THIS AFTN. UP TO
A COUPLE OF INCHES OF SNOW IS EXPECTED TO FALL ACROSS PARTS OF
NORTHEASTERN WYOMING...BUT WITH SFC TEMPS RISING ABOVE THE
FREEZING MARK LATER THIS MORNING...SNOW ACCUMULATIONS ON THE ROADS
THERE MAY BE LIMITED. UP TO 3 INCHES OF SNOW IS EXPECTED ACROSS
THE NORTHWESTERN PARTS OF THE BLACK HILLS TODAY WITH LOCALLY
HIGHER AMOUNTS POSSIBLE OVER THE HIGHEST ELEVATIONS.

THE SFC LOW WILL DROP SOUTHEASTWARD FROM WESTERN NORTH DAKOTA AROUND
MID-DAY INTO EASTERN SOUTH DAKOTA THIS EVENING. NORTHWESTERLY WINDS
WILL BECOME VERY WINDY ACROSS NORTHWESTERN SOUTH DAKOTA THIS
AFTERNOON AS THE LOW DROPS SOUTHWARD AND TIGHTENS THE SFC PRESSURE
GRADIENT. THE ARRIVAL OF THE COLDER AIR LOOKS LIKE IT WILL BE
DELAYED UNTIL THIS EVENING BUT THEN GUSTY WINDS WILL SPREAD
SOUTHWARD ACROSS THE AREA AS THE COOLER AIR MOVES INTO THE AREA.
AT THIS TIME IT LOOKS LIKE MOST OF THE SNOW WILL BE OVER BY THE
TIME THE WIND PICKS UP OVER NORTHWESTERN SOUTH DAKOTA THIS AFTN
AND DUE TO THE WARM TEMPS BLOWING SNOW SHOULDN/T BE MUCH OF A
PROBLEM. THEREFORE HAVE DECIDED TO ISSUE A WIND ADVISORY FROM LATE
THIS AFTERNOON INTO TONIGHT. IF THE PRECIPITATION LINGERS LONGER
OR THE SNOW IS A BIT HEAVIER OVER NWRN SD WHEN THE WIND INCREASES
THEN THE WIND ADVISORY THERE MAY NEED TO BE CHANGED TO A WINTER
WEATHER ADVISORY UNTIL THE SNOW TAPERS OFF. 06 NAM SHOWS 850MB
WINDS INCREASING TO 45-50KTS BEHIND THE FRONT THIS AFT/EVE.
HOWEVER THERE ISN/T A VERY STRONG TEMPERATURE CONTRAST ALONG OR
DIRECTLY BEHIND THE FRONTAL BOUNDARY. THIS IS EXPECTED TO LIMIT
MIXING AND THE POTENTIAL MOMENTUM TRANSFER TO THE SFC SO IT LOOKS
LIKE THE WIND ADVISORY WILL BE ADEQUATE FOR THE SITUTATION.

THE PRECIPITATION WILL DIMINISH THIS EVENING ALTHOUGH FLURRIES OR
LIGHT SNOW ARE POSSIBLE THROUGH THE NIGHT AS THE COLDER AIR
CONTINUES TO FLOW INTO THE REGION. THERE IS A ANOTHER CHANCE OF
LIGHT SNOW ON WEDNESDAY AS A NE-SW ORIENTED REGION OF MID LEVEL
FRONTOGENESIS WORKS EASTWARD ACROSS THE FORECAST AREA AND RELATIVELY
WARMER AIR ALOFT OVER RIDES THE COLDER AIR AT THE SFC.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 254 AM MST TUE NOV 25 2014

LOW AMPLITUDE RIDGING WILL DEVELOP THANKSGIVING DAY
ACROSS THE ROCKIES INTO THE NORTHERN PLAINS. STRONG WARM AIR
ADVECTION WILL DEVELOP WEDNESDAY NIGHT INTO THURSDAY PUSHING THE
WARM FRONT NE INTO THE CENTRAL DAKOTAS. THE RESULT WILL BE DRY AND
MUCH WARMER WEATHER FOR THANKSGIVING AND FRIDAY. CNTRL SD WILL REACH
THE 30S AS THE FRONTAL BOUNDARY GRADUALLY PUSHES THROUGH DURING THE
DAY. FARTHER WEST INTO THE WARM SECTOR...HIGHS WILL LIKELY REACH
WELL INTO THE 40S TO POSSIBLY LOWER 50S. ON FRIDAY...HIGHS WILL
REACH THE UPPER 40S TO UPPER 50S.

THE NEXT COLD FRONT WILL CROSS THE AREA SATURDAY AS A SHALLOW TROUGH
CROSSES SRN CANADA INTO MT/ND. IF THIS SOLUTION PANS OUT...TEMPS
WILL BE DROPPING THROUGH THE DAY SATURDAY INTO THE TEENS AND
20S...AND THEN SINGLE DIGITS OVERNIGHT. WELL BELOW AVERAGE TEMPS ARE
EXPECTED AGAIN SUNDAY...BUT THEN MODELS SHOW WARMER AIR ADVECTING
BACK IN EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
AT THIS TIME IT APPEARS SOME SNOW WILL ACCOMPANY THE FRONTAL
PASSAGE/CAA SATURDAY AND SUNDAY...BUT IT APPEARS QPF WILL BE MINIMAL.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 254 AM MST TUE NOV 25 2014

SNOW WILL REDEVELOP ACROSS THE REGION FROM THE NW TO SE
THIS MORNING BRINGING WIDESPREAD MVFR/IFR CONDITIONS. SOME LIFR
CONDITIONS EXPECTED AROUND THE NRN BLKHLS. GUSTY W/NW WINDS EXPECTED
TO DEVELOP BY THIS AFTERNOON.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
     SDZ014-025-026-031-032-043-072-073.

     WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST WEDNESDAY FOR
     SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...13







000
FXUS63 KUNR 251031
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
331 AM MST TUE NOV 25 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 254 AM MST TUE NOV 25 2014

MORNING UPPER ANALYSIS SHOWED A TROUGH OVER THE EASTERN HALF OF THE
CONUS WITH A RIDGE OFF THE WEST COAST. A SHORTWAVE TROUGH
CURRENTLY LOCATED OVER MONTANA WILL CROSS THE DAKOTAS TODAY INTO
TONIGHT. A SFC LOW WAS LOCATED OVER ALBERTA WITH DEEPENING LEE
SIDE SFC TROUGH EAST OF THE NRN ROCKIES.

MID-HIGH LEVEL WAA AND MOISTURE WILL INCREASE AHEAD OF THE SHORTWAVE
TROUGH THIS MORNING...SPREADING WIDESPREAD CLOUDS AND PRECIPITATION ACROSS
THE AREA. MAINLY SNOW IS EXPECTED THIS MORNING AS THE PRECIP MOVES
IN FROM THE NORTHWEST BUT GIVEN THE WARMING PROFILES THERE MAY BE
A MIX OF RAIN AND SNOW ACROSS MUCH OF THE PLAINS THIS AFTN. UP TO
A COUPLE OF INCHES OF SNOW IS EXPECTED TO FALL ACROSS PARTS OF
NORTHEASTERN WYOMING...BUT WITH SFC TEMPS RISING ABOVE THE
FREEZING MARK LATER THIS MORNING...SNOW ACCUMULATIONS ON THE ROADS
THERE MAY BE LIMITED. UP TO 3 INCHES OF SNOW IS EXPECTED ACROSS
THE NORTHWESTERN PARTS OF THE BLACK HILLS TODAY WITH LOCALLY
HIGHER AMOUNTS POSSIBLE OVER THE HIGHEST ELEVATIONS.

THE SFC LOW WILL DROP SOUTHEASTWARD FROM WESTERN NORTH DAKOTA AROUND
MID-DAY INTO EASTERN SOUTH DAKOTA THIS EVENING. NORTHWESTERLY WINDS
WILL BECOME VERY WINDY ACROSS NORTHWESTERN SOUTH DAKOTA THIS
AFTERNOON AS THE LOW DROPS SOUTHWARD AND TIGHTENS THE SFC PRESSURE
GRADIENT. THE ARRIVAL OF THE COLDER AIR LOOKS LIKE IT WILL BE
DELAYED UNTIL THIS EVENING BUT THEN GUSTY WINDS WILL SPREAD
SOUTHWARD ACROSS THE AREA AS THE COOLER AIR MOVES INTO THE AREA.
AT THIS TIME IT LOOKS LIKE MOST OF THE SNOW WILL BE OVER BY THE
TIME THE WIND PICKS UP OVER NORTHWESTERN SOUTH DAKOTA THIS AFTN
AND DUE TO THE WARM TEMPS BLOWING SNOW SHOULDN/T BE MUCH OF A
PROBLEM. THEREFORE HAVE DECIDED TO ISSUE A WIND ADVISORY FROM LATE
THIS AFTERNOON INTO TONIGHT. IF THE PRECIPITATION LINGERS LONGER
OR THE SNOW IS A BIT HEAVIER OVER NWRN SD WHEN THE WIND INCREASES
THEN THE WIND ADVISORY THERE MAY NEED TO BE CHANGED TO A WINTER
WEATHER ADVISORY UNTIL THE SNOW TAPERS OFF. 06 NAM SHOWS 850MB
WINDS INCREASING TO 45-50KTS BEHIND THE FRONT THIS AFT/EVE.
HOWEVER THERE ISN/T A VERY STRONG TEMPERATURE CONTRAST ALONG OR
DIRECTLY BEHIND THE FRONTAL BOUNDARY. THIS IS EXPECTED TO LIMIT
MIXING AND THE POTENTIAL MOMENTUM TRANSFER TO THE SFC SO IT LOOKS
LIKE THE WIND ADVISORY WILL BE ADEQUATE FOR THE SITUTATION.

THE PRECIPITATION WILL DIMINISH THIS EVENING ALTHOUGH FLURRIES OR
LIGHT SNOW ARE POSSIBLE THROUGH THE NIGHT AS THE COLDER AIR
CONTINUES TO FLOW INTO THE REGION. THERE IS A ANOTHER CHANCE OF
LIGHT SNOW ON WEDNESDAY AS A NE-SW ORIENTED REGION OF MID LEVEL
FRONTOGENESIS WORKS EASTWARD ACROSS THE FORECAST AREA AND RELATIVELY
WARMER AIR ALOFT OVER RIDES THE COLDER AIR AT THE SFC.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 254 AM MST TUE NOV 25 2014

LOW AMPLITUDE RIDGING WILL DEVELOP THANKSGIVING DAY
ACROSS THE ROCKIES INTO THE NORTHERN PLAINS. STRONG WARM AIR
ADVECTION WILL DEVELOP WEDNESDAY NIGHT INTO THURSDAY PUSHING THE
WARM FRONT NE INTO THE CENTRAL DAKOTAS. THE RESULT WILL BE DRY AND
MUCH WARMER WEATHER FOR THANKSGIVING AND FRIDAY. CNTRL SD WILL REACH
THE 30S AS THE FRONTAL BOUNDARY GRADUALLY PUSHES THROUGH DURING THE
DAY. FARTHER WEST INTO THE WARM SECTOR...HIGHS WILL LIKELY REACH
WELL INTO THE 40S TO POSSIBLY LOWER 50S. ON FRIDAY...HIGHS WILL
REACH THE UPPER 40S TO UPPER 50S.

THE NEXT COLD FRONT WILL CROSS THE AREA SATURDAY AS A SHALLOW TROUGH
CROSSES SRN CANADA INTO MT/ND. IF THIS SOLUTION PANS OUT...TEMPS
WILL BE DROPPING THROUGH THE DAY SATURDAY INTO THE TEENS AND
20S...AND THEN SINGLE DIGITS OVERNIGHT. WELL BELOW AVERAGE TEMPS ARE
EXPECTED AGAIN SUNDAY...BUT THEN MODELS SHOW WARMER AIR ADVECTING
BACK IN EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
AT THIS TIME IT APPEARS SOME SNOW WILL ACCOMPANY THE FRONTAL
PASSAGE/CAA SATURDAY AND SUNDAY...BUT IT APPEARS QPF WILL BE MINIMAL.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 254 AM MST TUE NOV 25 2014

SNOW WILL REDEVELOP ACROSS THE REGION FROM THE NW TO SE
THIS MORNING BRINGING WIDESPREAD MVFR/IFR CONDITIONS. SOME LIFR
CONDITIONS EXPECTED AROUND THE NRN BLKHLS. GUSTY W/NW WINDS EXPECTED
TO DEVELOP BY THIS AFTERNOON.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
     SDZ014-025-026-031-032-043-072-073.

     WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST WEDNESDAY FOR
     SDZ001-002-012-013.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS65 KRIW 250955
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
255 AM MST TUE NOV 25 2014

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.
&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS









000
FXUS65 KRIW 250955
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
255 AM MST TUE NOV 25 2014

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.
&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS









000
FXUS65 KRIW 250955
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
255 AM MST TUE NOV 25 2014

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.
&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS









000
FXUS65 KRIW 250955
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
255 AM MST TUE NOV 25 2014

.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT

ONCE AGAIN WE THE ACTIVE PATTERN WE WILL DIVIDE THE FORECAST UP
BETWEEN WEST AND EAST OF THE DIVIDE.

WEST OF THE DIVIDE...THE POCATELLO RADAR IS FILLING RATHER NICELY AS
THE NEXT SYSTEM MOVES IN FROM THE WEST. WARM ADVECTION SNOW IS NOW
SPREADING INTO THE WESTERN MOUNTAINS. WE STILL ANTICIPATE THE THEN
HEAVIEST SNOW TO BE FROM MID MORNING INTO THE AFTERNOON WITH THE
BEST MOISTURE AND WARM ADVECTION. FOR THE MOST PART...THE CURRENT
HIGHLIGHTS LOOK PRETTY DARN GOOD AND WE WILL LET THEM RIDE FOR
NOW. THERE IS ONE EXCEPTION HOWEVER...THAT IS THE JACKSON VALLEY.
THIS ONE IS A TOUGH CALL. THE PROBLEM IS THE DIFFERENT IN THE
MODELS AND THE 700 MILLIBAR TEMPERATURES THAT WILL BE CRITICAL.
THERE IS A DIFFERENCE WITH THE MODELS THOUGH. THE GFS IS WARMER
WITH 700 MILLIBAR TEMPERATURES RISING TO AROUND -3 TO -3.5 WHICH
WOULD PUSH THE SNOW LEVELS UP TO AROUND 7000 FEET AND BRING SOME
MIXING AND POSSIBLY CHANGING OVER TO RAIN. THE NAM MEANWHILE IS
COLDER WITH TEMPERATURES AROUND MINUS 4 TO 5 WHICH WOULD KEEP MOST
OF THE VALLEY AS ALL SNOW. FOR NOW WE DECIDED TO COMPROMISE...WE
WILL ISSUE A WINTER WEATHER ADVISORY. HOWEVER...THE BEST CHANCE OF
ADVISORY LEVEL SNOW WOULD BE NORTH OF THE JACKSON HOLE AIRPORT
TOWARD MOOSE AND MORAN JUNCTION. WE WILL SPECIFY THAT IN THE
ADVISORY. SNOW WILL BEGIN TO LIGHTEN TONIGHT AND ESPECIALLY
TOMORROW AS RIDGING BEGINS TO BUILD ACROSS THE AREA FROM THE SOUTH
AND WEST AND THE BEST UPPER LEVEL SUPPORT LIFTS OUT. COVERAGE WILL
CONTINUE TO DECREASE THROUGH THE DAY WEDNESDAY BEFORE ENDING FOR
THE MOST PART BY WEDNESDAY EVENING. AT THIS TIME...WE HAVE DRIED
OUT THE WEATHER FOR THURSDAY FOR ALL AREAS WITH THE RIDGE OVER THE
AREA. ANOTHER SYSTEM MAY MOVE IN FOR LATER THURSDAY NIGHT BUT WITH
MODELS DISAGREEMENT WE KEPT THINGS MAINLY DRY FOR NOW.

EAST OF THE DIVIDE...A TRICKY FORECAST HERE AS WELL. FIRST FOR THE
POTENTIAL FOR SNOW. AGAIN...THE MODELS ARE SPLIT. THE NAM IS THE
DRIEST AGAIN WITH THE GFS AND EUROPEAN A BIT WETTER. CONTINUITY FOR
THE BIG HORN RANGE LOOKS PRETTY GOOD AT THIS TIME WITH FAVORABLE
NORTHWEST FLOW BRINGING THE BEST ACCUMULATIONS TO THE WESTERN
SLOPES. SOME AREAS COULD REACH WARNING CRITERIA BUT WE STILL THINK
THIS SHOULD BE FAIRLY ISOLATED. THE BIG QUESTION IS FOR THE
BASINS...ESPECIALLY THE BIG HORN BASIN. SOME OF THE MODELS DO BRING
A DECENT AMOUNT OF QPF IN THAT AREA AS A BACKDOOR COLD FRONT GETS
OVERRUN BY THE MOISTURE COMING IN FROM THE WEST. IT LOOKS LIKE A
FAIRLY GOOD CHANCE OF PRECIPITATION FOR SOME AREAS...ESPECIALLY THE
EASTERN BIG HORN BASIN AND JOHNSON COUNTY SO WE BUMPED THE POPS UP
TO LIKELY. THE NEXT QUESTION IS HOW MUCH SNOW WILL FALL.
TEMPERATURES ARE FAIRLY BORDERLINE HERE AS WELL. AGAIN...AS A
COMPROMISE WE RAISED AMOUNTS OF QPF AND SNOW. WE DID KEEP THE
AMOUNTS UNDER ADVISORY LEVELS HOWEVER. WE GUT FEELING IS THAT THE
BEST CHANCE OF ACCUMULATING SNOW WOULD BE TONIGHT SO THIS COULD BE
RE-EVALUATED BY THE DAY SHIFT. LIKE WEST OF THE DIVIDE...COVERAGE
WILL DECREASE FROM THE SOUTH TO NORTH AS THE BEST SUPPORT MOVES AWAY
AND RIDGING BUILDS ACROSS THE AREA. AT THIS TIME...THE PERIOD FROM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS MAINLY DRY.

NOW FOR ACT TWO...THE HIGH WIND. AS EXPECTED...THE MOST IMPORTANT
CROSSROADS IN AMERICA...CLARK...HAS ALREADY REPORTED WINDS OVER 60
MPH. HOWEVER...STRONG WINDS HAVE MOVED OFF THAT WIND PRONE AREA WITH
A GUST TO 56 MPH REPORTED AT THE CODY AIRPORT. FOR NOW...WE WILL
CONTINUE THE HIGH WIND WARNING. HOWEVER...WINDS WILL BE RATHER GUSTY
ACROSS MUCH OF THE AREA TODAY. AT THIS TIME...NO FURTHER HIGH WIND
WARNINGS ARE ANTICIPATED. THE MAV MOS AT ROCK SPRINGS DOES HAVE HIGH
WIND CRITERIA...BUT THIS IS USUALLY OVERDONE.  FOR NOW...WE WILL
CONTINUE THE SPECIAL WEATHER STATEMENT BUT THIS WILL HAVE TO BE
WATCHED...ESPECIALLY FOR ZONE 30. THE WIND SHOULD DECREASE TONIGHT
AS THE SUPPORTING JET STREAK MOVES AWAY AND THE PRESSURE GRADIENT
LESSENS. GUSTY BREEZES WILL CONTINUE FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT ALTHOUGH NOT AS STRONG AS TODAY.

.LONG TERM...FRIDAY THROUGH TUESDAY

MEDIUM RANGE STARTS OUT WITH A FLAT RIDGE AXIS JUST TO OUR WEST
WHILE A COLD TROUGH MOVES SSEWD INTO SRN B.C. MILD AIR AHEAD OF THIS
WILL LIKELY LEAD TO RATHER MILD LATE NOVEMBER DAY ACROSS MUCH OF THE
AREA...ESPECIALLY EAST OF THE DIVIDE WHERE THERE WILL BE 50S IN MANY
AREAS. WINDS MAY ALSO BE A SIGNIFICANT FACTOR...ESPECIALLY FOR THE
MOUNTAINS...WIND CORRIDOR AND CODY FOOTHILLS AS STRONG WLY FLOW
COMBINES WITH A STRENGTHENING SFC PRESSURE GRADIENT AS A STRONG LOW
FORMS OVER MONTANA. THE COLD TROUGH TO THE NW HAS ITS ORIGINS AROUND
THE NORTH POLE AND WILL LIKELY CONTAIN QUITE A BIT OF COLD AIR.
RIGHT NOW THE MODELS ARE KEEPING THE MAJORITY OF THE ENERGY TO THE
NORTH BUT DO HAVE AT LEAST A SHALLOW...COLD AIRMASS TRYING TO SETTLE
IN EAST OF THE DIVIDE OVER THE WEEKEND. THE EURO IS COLDER
AGAIN...FASTER AND FURTHER SOUTH WITH THE COLD AIR PUSH BRINGING THE
COLD AIR INTO THE NORTH QUICKLY SATURDAY MORNING AND TO ALL AREAS
EAST OF THE DIVIDE BY SATURDAY AFTERNOON. THE GFS IS NOT AS COLD
AND HINTS AT KEEPING THE FRONT JUST NORTH OF THE CENTRAL ZONES.
WILL KEEP THE CENTRAL ZONES ABOVE NORMAL THROUGH SATURDAY WITH
SOME COOLING ON SUNDAY. THE FAR NRN ZONES MAY BE QUITE CHILLY WITH
THIS SYSTEM BUT WITH LIMITED FORCING AND THUS NOT MUCH SNOW FOR
THE LOWER ELEVATIONS. IN THE WEST AND NRN MOUNTAINS...A MOIST WLY
FLOW WILL LIKELY LEAD TO SOME LIGHT TO MODERATE SNOW AT TIMES
THROUGH THE WEEKEND WITH POTENTIAL FOR SOME OVERRUNNING EAST OF
THE DIVIDE IF THE LOW LEVEL COLD AIR BECOMES ENTRENCHED. EARLY
NEXT WEEK...WE GET A NEW SYSTEM MOVING ONTO THE WEST COAST THAT IS
FORECAST TO MOVE ACROSS US ON TUESDAY. THIS SYSTEM IS THE ONE NEAR
KAMCHATKA RIGHT NOW AND EVENTUALLY THERE IS A SPLIT WITH THE SRN
PIECE COMING ON THE CA/OR COAST WITH THE NRN PIECE PROVIDING SOME
COLDER AIR AS IT MOVES INLAND. LOT OF DETAIL ISSUES THIS FOR OUT
SO CONFIDENCE ON TIMING AND PCPN POTENTIAL IS LOW RIGHT NOW. WILL
KEEP MOST OF THE SNOW POTENTIAL CONFINED TO THE WEST A LITTLE IN
SOUTH FOR NOW AS THIS SYSTEM MOVES THROUGH. LATER SHIFTS CAN WATCH
THIS EVOLUTION.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH THIS EVENING. THIS WILL CREATE SOME MOUNTAIN WAVE
ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS TODAY. A GUSTY WIND
WILL  OCCUR AT KCOD AND KCPR TODAY. MOUNTAIN SNOW WILL OCCUR IN THE
NORTHERN BIGHORN MOUNTAINS AND THE ABSAROKA MOUNTAINS AS WELL AS THE
WIND RIVER MOUNTAINS THROUGH TONIGHT. EXPECT MVFR/IFR CONDITIONS
OVER AND NEAR THE MOUNTAINS. THE LOWER ELEVATIONS OF THE NORTH AFTER
00Z WILL SEE MVFR/IFR CONDITIONS DEVELOP ALONG WITH SOME LIGHT SNOW.
THESE CONDITIONS WILL SPREAD SOUTHWARD TOWARD KCPR AIRPORT BY 05Z
AND CONTINUE THROUGH 12Z WED.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 12Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS FROM 18Z
UNTIL 03Z. MVFR TO IFR CONDITIONS WILL BE COMMON OVER THE WEST
THROUGH THE PERIOD. PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE
DETAILS. EXPECT A STRONG GUSTY WIND AT KRKS AIRPORT TODAY AND
TONIGHT.
&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TODAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH THIS AFTERNOON. SNOW SHOWERS WILL DRIFT
OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME...ESPECIALLY
ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY.  HIGH PRESSURE AND
DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS ON
WEDNESDAY AND THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY
WYZ001-002-008-009-013-014-024.

WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY WYZ012.

HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING WYZ003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AR
FIRE WEATHER...HATTINGS









000
FXUS65 KCYS 250514
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1014 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 250514
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1014 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 250514
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1014 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 250514
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1014 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1012 PM MST MON NOV 24 2014

VFR CONDITIONS OVERNIGHT WITH SOUTHWEST WINDS INCREASING EARLY
TUESDAY MORNING AND PERISTING THROUGH EARLY EVENING. EXPECTING
SNOW TO DEVELOP ACROSS CARBON COUNTY LATE MORNING
TUESDAY...SPREADING EAST TO KLAR AND POSSIBLY KCYS BY LATE
AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KRIW 250512
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1012 PM MST MON NOV 24 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT (ISSUED AT 406 PM MST)

A CLOCKWISE FLOW OF SUBTROPICAL PACIFIC MOISTURE WILL FLOW UP AND
OVER THE FLAT RIDGE OFF THE PACIFIC COAST INTO WYOMING LATER
TONIGHT THROUGH 12Z WEDNESDAY AS A TROUGH MAKING LANDFALL ONTO THE
BRITISH COLUMBIA COAST DRAGS THE MOISTURE INTO THE AREA. MAINLY
ADVISORY AMOUNTS ARE EXPECTED BUT DECIDED TO KEEP WARNING AMOUNTS
IN THE TETONS AS THIS NW FLOW IS A FAVORABLE FLOW PATTERN FOR
THOSE MTNS. DECIDED NOT TO ISSUE A WINTER WEATHER ADVISORY FOR
THE FAR WEST VALLEYS SINCE THE SNOW IS EXPECTED TO TURN TO RAIN BY
TUESDAY AFTERNOON WITH SNOW LEVELS EXPECTED TO LIFT TO 7K. VALLEY
RAIN SHOULD TURN BACK INTO SNOW TUESDAY NIGHT. THIS IS ALSO A
FAVORABLE FLOW PATTERN FOR THE BIG HORN MOUNTAINS GIVEN THE NW FLOW
AND THE VORT MAX TRACKING SOUTHEAST ACROSS THE NORTHERN PLAINS. WENT
WITH AN ADVISORY FOR THE BIG HORN MTNS DURING THE SAME TIME FRAME AS
WELL. SOME OF THE HEAVIEST SNOW IN THE HILITED AREAS SHOULD TAKE
PLACE TONIGHT WHEN THE MOST FAVORABLE DENDRITIC GROWTH WILL TAKE
PLACE AND WHEN THE JET STREAM WHICH WILL BE OVERHEAD TONIGHT DRAWING
IN MOISTURE FROM THE NW. ISENTROPIC LIFT WILL HELP GET THE INITIAL
STEADY LIGHT SNOWFALL UNDERWAY IN THE BIG HORN MTNS INITIALLY. Q G
FORCING WILL ALSO HELP ENHANCE THE SNOWFALL FOR THE HILITED AREAS,
THIS EVENT STILL APPEARS THAT IT WILL PERSIST THROUGH 12Z WED.

AS FOR WIND...IT APPEARS THAT THE CODY FOOTHILLS...SPECIFICALLY
CLARK...WILL SEE A LOW END HIGH WIND WARNING BASED ON A 14C H7
TEMP SPREAD BETWEEN YNP AND THE CODY FOOTHILLS INITIATING GAP
FLOW. IN ADDITION...THE JET STREAM WILL BISECT THE CWA FROM SW TO
NE TONIGHT WHICH WILL PLACE THE RIGHT FRONT QUAD OF THE JET OVER
NORTHERN WY SURFACING THE H7 55 KNOT WINDS TO THE SURFACE. THERE
DOES NOT APPEAR TO BE A STRONG MTN WAVE SIGNATURE HOWEVER. CROSS
SECTIONS HAVE 50 KNOT WINDS CLOSE TO THE SURFACE NEAR CLARK.
UPGRADED THE HIGH WIND WATCH TO A WARNING FOR THE CODY FOOTHILLS FOR
LATE TONIGHT AND TUESDAY MORNING. WILL BE ISSUING A SPECIAL WEATHER
STATEMENT FOR STRONG SUB WARNING CRITERIA WINDS ANTICIPATED FROM RKS
TO CPR FOR TUESDAY GIVEN THE 55 KNOT H7 WINDS...RIGHT FRONT QUAD
DYNAMICS...6 DECAMETER H7 HEIGHT LINES SPACED APART EVERY 3
DECAMATERS ACROSS WY AS WELL AS 31 KNOT WINDS ON MOS GUIDANCE FOR
RKS. EXPECTING 30 TO 40 MPH WINDS WITH GUSTS TO 50 MPH ALONG THE
SOUTHERN WIND CORRIDOR TUE.

HIGH TEMPS WILL BE ABOVE FREEZING IN THE WESTERN VALLEYS TUE WITH
HIGHS IN THE LOW 40S EAST.

.LONG TERM...WEDNESDAY THROUGH MONDAY

GLOBAL FORECAST MODELS IN FAIRLY GOOD AGREEMENT THE THE VAST
MAJORITY OF THE EXTENDED PERIOD. NORTHWEST FLOW ALOFT PERSISTS
WEDNESDAY AS RIDGE PUSHES INLAND AND INTO THE GREAT BASIN. JET
ENERGY AND MOISTURE LIFTS SLOWLY NORTHEAST WEDNESDAY AS HEIGHTS
BUILD IN ASSOCIATION WITH WESTERN RIDGE. SNOW WILL LINGER LONGEST
IN THE NORTHWEST AND THE BIGHORN MOUNTAINS. BEST SUNSHINE AND
WARMER TEMPERATURES ARE MOST LIKELY OVER THE SOUTHWEST.
ALSO...GUSTY SOUTHWEST WINDS WILL AID WARMING ACROSS SWEETWATER
COUNTY AND SURROUNDING LOCALES. CONDITIONS ARE MAINLY DRY THEN
FROM WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS FLAT RIDGE
TRAVERSES THE FORECAST AREA. 700MB TEMPERATURES ON THANKSGIVING
ARE LIKELY TO BE 0C TO +2C. FULL MIXING WOULD PUT HIGH
TEMPERATURES AROUND 60F. HAVE AT LEAST NUDGED IN THAT DIRECTION
BUT MOST MODEL GUIDANCE IS TEMPERING THAT AMOUNT OF WARMING.
CAVEAT AT THIS TIME OF YEAR WILL BE THE AMOUNT OF MID- UPPER LEVEL
CLOUD COVER. BOTH MODELS SHOW A BIT OF A BREAK IN THE CLOUD COVER
THANKSGIVING AFTERNOON...BUT TIMING IS DIFFICULT WITHIN THE
PROGRESSIVE WESTERLY FLOW. MUCH THE SAME STORY EXPECTED FOR FRIDAY
AS WESTERLY FLOW STRENGTHENS AND TEMPERATURES CONTINUE TO
WARM...ESPECIALLY EAST OF THE CONTINENTAL DIVIDE. WARMEST HIGH
TEMPERATURES ON FRIDAY WILL BE IN EASTERN FOOTHILL LOCATIONS WHERE
INCREASING DOWNSLOPE WIND IS LIKELY. MOIST FLOW REACHES THE FAR
WEST FRIDAY AFTERNOON AND EVENING WITH PRECIPITATION BEGINNING
BEFORE 00Z/SAT. TEMPERATURES INITIALLY FAVOR RAIN IN THE JACKSON
AND STAR VALLEYS. DYNAMIC COOLING COUPLED WITH GRADUALLY COOLING
700MB TEMPERATURES WILL ALLOW RAIN TO CHANGE OVER TO SNOW EARLY
SATURDAY MORNING. SNOW WILL BE MORE WIDESPREAD WEST OF THE DIVIDE
FRIDAY NIGHT AND SATURDAY AS WITH POTENTIAL HIGHLIGHT SNOW AMOUNTS
BY 00Z/SUN. BEST AREAS FOR NOW WILL BE THE TETONS...TOGWOTEE...AND
THE HIGHER ELEVATIONS OF SOUTHERN YELLOWSTONE NATIONAL PARK.
EARLIER MODEL RUNS WERE TRYING TO DRIVE A COLD FRONT SOUTH ON
SATURDAY EAST OF THE CONTINENTAL DIVIDE. APPEARS THIS FEATURE WILL
NOT PUSH THROUGH UNTIL SATURDAY NIGHT IF AT ALL. UPPER FLOW
PARALLELS THIS FRONT AND MAY HINDER ITS SOUTHWARD PROGRESSION.
ALSO...SHORTWAVE ENERGY ACROSS SOUTHERN CANADA BECOMES ELONGATED
EAST-TO-WEST AND SHOWS LITTLE PUSH TO THE SOUTH. THEREFORE...COULD
EASILY IMAGINE THAT TEMPERATURES EAST OF THE DIVIDE COULD BE
WARMER THAN ADVERTISED AND FORECAST BASED ON THIS SCENARIO. SOME
WARMING ON MONDAY AS SOUTHWEST FLOW INCREASES AHEAD OF THE NEXT
WEATHER SYSTEM PUSHING INTO CALIFORNIA AND THE DESERT SOUTHWEST.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH TUESDAY EVENING. THIS WILL CREATE SOME MOUNTAIN
WAVE ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS. A GUSTY WIND
WILL OCCUR AT KCOD AND KCPR OVERNIGHT THROUGH TUESDAY. MOUNTAIN SNOW
WILL DEVELOP OVERNIGHT IN THE NORTHERN BIGHORN MOUNTAINS AND THE
ABSAROKA MOUNTAINS...CONTINUING THROUGH TUESDAY EVENING. EXPECT
MVFR/IFR CONDITIONS OVER AND NEAR THE MOUNTAINS. THE LOWER
ELEVATIONS OF THE NORTH AFTER 00Z WILL SEE MVFR/IFR CONDITIONS
DEVELOP ALONG WITH SOME LIGHT SNOW. THESE CONDITIONS WILL SPREAD
SOUTHWARD TOWARD KCPR AIRPORT BY 05Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 06Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS. MVFR TO
IFR CONDITIONS WILL BE COMMON OVER THE WEST THROUGH THE PERIOD.
PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE DETAILS. EXPECT A
STRONG GUSTY WIND AT KRKS AIRPORT TUESDAY INTO TUESDAY EVENING.

&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TUESDAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH TUESDAY AFTERNOON. A FEW SNOW SHOWERS
MAY DRIFT OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME. HIGH
PRESSURE AND DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS
ON WEDNESDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ001-002-008-009-014-024.

WINTER STORM WARNING FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ012.

HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY
WYZ003.

&&

$$

SHORT TERM...LIPSON
LONG TERM...CNJ
AVIATION...AR
FIRE WEATHER...LIPSON








000
FXUS65 KRIW 250512
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1012 PM MST MON NOV 24 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT (ISSUED AT 406 PM MST)

A CLOCKWISE FLOW OF SUBTROPICAL PACIFIC MOISTURE WILL FLOW UP AND
OVER THE FLAT RIDGE OFF THE PACIFIC COAST INTO WYOMING LATER
TONIGHT THROUGH 12Z WEDNESDAY AS A TROUGH MAKING LANDFALL ONTO THE
BRITISH COLUMBIA COAST DRAGS THE MOISTURE INTO THE AREA. MAINLY
ADVISORY AMOUNTS ARE EXPECTED BUT DECIDED TO KEEP WARNING AMOUNTS
IN THE TETONS AS THIS NW FLOW IS A FAVORABLE FLOW PATTERN FOR
THOSE MTNS. DECIDED NOT TO ISSUE A WINTER WEATHER ADVISORY FOR
THE FAR WEST VALLEYS SINCE THE SNOW IS EXPECTED TO TURN TO RAIN BY
TUESDAY AFTERNOON WITH SNOW LEVELS EXPECTED TO LIFT TO 7K. VALLEY
RAIN SHOULD TURN BACK INTO SNOW TUESDAY NIGHT. THIS IS ALSO A
FAVORABLE FLOW PATTERN FOR THE BIG HORN MOUNTAINS GIVEN THE NW FLOW
AND THE VORT MAX TRACKING SOUTHEAST ACROSS THE NORTHERN PLAINS. WENT
WITH AN ADVISORY FOR THE BIG HORN MTNS DURING THE SAME TIME FRAME AS
WELL. SOME OF THE HEAVIEST SNOW IN THE HILITED AREAS SHOULD TAKE
PLACE TONIGHT WHEN THE MOST FAVORABLE DENDRITIC GROWTH WILL TAKE
PLACE AND WHEN THE JET STREAM WHICH WILL BE OVERHEAD TONIGHT DRAWING
IN MOISTURE FROM THE NW. ISENTROPIC LIFT WILL HELP GET THE INITIAL
STEADY LIGHT SNOWFALL UNDERWAY IN THE BIG HORN MTNS INITIALLY. Q G
FORCING WILL ALSO HELP ENHANCE THE SNOWFALL FOR THE HILITED AREAS,
THIS EVENT STILL APPEARS THAT IT WILL PERSIST THROUGH 12Z WED.

AS FOR WIND...IT APPEARS THAT THE CODY FOOTHILLS...SPECIFICALLY
CLARK...WILL SEE A LOW END HIGH WIND WARNING BASED ON A 14C H7
TEMP SPREAD BETWEEN YNP AND THE CODY FOOTHILLS INITIATING GAP
FLOW. IN ADDITION...THE JET STREAM WILL BISECT THE CWA FROM SW TO
NE TONIGHT WHICH WILL PLACE THE RIGHT FRONT QUAD OF THE JET OVER
NORTHERN WY SURFACING THE H7 55 KNOT WINDS TO THE SURFACE. THERE
DOES NOT APPEAR TO BE A STRONG MTN WAVE SIGNATURE HOWEVER. CROSS
SECTIONS HAVE 50 KNOT WINDS CLOSE TO THE SURFACE NEAR CLARK.
UPGRADED THE HIGH WIND WATCH TO A WARNING FOR THE CODY FOOTHILLS FOR
LATE TONIGHT AND TUESDAY MORNING. WILL BE ISSUING A SPECIAL WEATHER
STATEMENT FOR STRONG SUB WARNING CRITERIA WINDS ANTICIPATED FROM RKS
TO CPR FOR TUESDAY GIVEN THE 55 KNOT H7 WINDS...RIGHT FRONT QUAD
DYNAMICS...6 DECAMETER H7 HEIGHT LINES SPACED APART EVERY 3
DECAMATERS ACROSS WY AS WELL AS 31 KNOT WINDS ON MOS GUIDANCE FOR
RKS. EXPECTING 30 TO 40 MPH WINDS WITH GUSTS TO 50 MPH ALONG THE
SOUTHERN WIND CORRIDOR TUE.

HIGH TEMPS WILL BE ABOVE FREEZING IN THE WESTERN VALLEYS TUE WITH
HIGHS IN THE LOW 40S EAST.

.LONG TERM...WEDNESDAY THROUGH MONDAY

GLOBAL FORECAST MODELS IN FAIRLY GOOD AGREEMENT THE THE VAST
MAJORITY OF THE EXTENDED PERIOD. NORTHWEST FLOW ALOFT PERSISTS
WEDNESDAY AS RIDGE PUSHES INLAND AND INTO THE GREAT BASIN. JET
ENERGY AND MOISTURE LIFTS SLOWLY NORTHEAST WEDNESDAY AS HEIGHTS
BUILD IN ASSOCIATION WITH WESTERN RIDGE. SNOW WILL LINGER LONGEST
IN THE NORTHWEST AND THE BIGHORN MOUNTAINS. BEST SUNSHINE AND
WARMER TEMPERATURES ARE MOST LIKELY OVER THE SOUTHWEST.
ALSO...GUSTY SOUTHWEST WINDS WILL AID WARMING ACROSS SWEETWATER
COUNTY AND SURROUNDING LOCALES. CONDITIONS ARE MAINLY DRY THEN
FROM WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS FLAT RIDGE
TRAVERSES THE FORECAST AREA. 700MB TEMPERATURES ON THANKSGIVING
ARE LIKELY TO BE 0C TO +2C. FULL MIXING WOULD PUT HIGH
TEMPERATURES AROUND 60F. HAVE AT LEAST NUDGED IN THAT DIRECTION
BUT MOST MODEL GUIDANCE IS TEMPERING THAT AMOUNT OF WARMING.
CAVEAT AT THIS TIME OF YEAR WILL BE THE AMOUNT OF MID- UPPER LEVEL
CLOUD COVER. BOTH MODELS SHOW A BIT OF A BREAK IN THE CLOUD COVER
THANKSGIVING AFTERNOON...BUT TIMING IS DIFFICULT WITHIN THE
PROGRESSIVE WESTERLY FLOW. MUCH THE SAME STORY EXPECTED FOR FRIDAY
AS WESTERLY FLOW STRENGTHENS AND TEMPERATURES CONTINUE TO
WARM...ESPECIALLY EAST OF THE CONTINENTAL DIVIDE. WARMEST HIGH
TEMPERATURES ON FRIDAY WILL BE IN EASTERN FOOTHILL LOCATIONS WHERE
INCREASING DOWNSLOPE WIND IS LIKELY. MOIST FLOW REACHES THE FAR
WEST FRIDAY AFTERNOON AND EVENING WITH PRECIPITATION BEGINNING
BEFORE 00Z/SAT. TEMPERATURES INITIALLY FAVOR RAIN IN THE JACKSON
AND STAR VALLEYS. DYNAMIC COOLING COUPLED WITH GRADUALLY COOLING
700MB TEMPERATURES WILL ALLOW RAIN TO CHANGE OVER TO SNOW EARLY
SATURDAY MORNING. SNOW WILL BE MORE WIDESPREAD WEST OF THE DIVIDE
FRIDAY NIGHT AND SATURDAY AS WITH POTENTIAL HIGHLIGHT SNOW AMOUNTS
BY 00Z/SUN. BEST AREAS FOR NOW WILL BE THE TETONS...TOGWOTEE...AND
THE HIGHER ELEVATIONS OF SOUTHERN YELLOWSTONE NATIONAL PARK.
EARLIER MODEL RUNS WERE TRYING TO DRIVE A COLD FRONT SOUTH ON
SATURDAY EAST OF THE CONTINENTAL DIVIDE. APPEARS THIS FEATURE WILL
NOT PUSH THROUGH UNTIL SATURDAY NIGHT IF AT ALL. UPPER FLOW
PARALLELS THIS FRONT AND MAY HINDER ITS SOUTHWARD PROGRESSION.
ALSO...SHORTWAVE ENERGY ACROSS SOUTHERN CANADA BECOMES ELONGATED
EAST-TO-WEST AND SHOWS LITTLE PUSH TO THE SOUTH. THEREFORE...COULD
EASILY IMAGINE THAT TEMPERATURES EAST OF THE DIVIDE COULD BE
WARMER THAN ADVERTISED AND FORECAST BASED ON THIS SCENARIO. SOME
WARMING ON MONDAY AS SOUTHWEST FLOW INCREASES AHEAD OF THE NEXT
WEATHER SYSTEM PUSHING INTO CALIFORNIA AND THE DESERT SOUTHWEST.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR CONDITIONS WILL PREVAIL THROUGH 00Z WED. STRONG WINDS ALOFT OVER
THE AREA THROUGH TUESDAY EVENING. THIS WILL CREATE SOME MOUNTAIN
WAVE ACTIVITY EAST OF THE MOUNTAINS AND AREAS OF LLWS. A GUSTY WIND
WILL OCCUR AT KCOD AND KCPR OVERNIGHT THROUGH TUESDAY. MOUNTAIN SNOW
WILL DEVELOP OVERNIGHT IN THE NORTHERN BIGHORN MOUNTAINS AND THE
ABSAROKA MOUNTAINS...CONTINUING THROUGH TUESDAY EVENING. EXPECT
MVFR/IFR CONDITIONS OVER AND NEAR THE MOUNTAINS. THE LOWER
ELEVATIONS OF THE NORTH AFTER 00Z WILL SEE MVFR/IFR CONDITIONS
DEVELOP ALONG WITH SOME LIGHT SNOW. THESE CONDITIONS WILL SPREAD
SOUTHWARD TOWARD KCPR AIRPORT BY 05Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

UNSETTLED WEATHER WILL BE THE RULE THROUGH 06Z WED. MOUNTAIN SNOW
WILL OCCUR WITH SNOW IN THE WESTERN VALLEYS THROUGH 18Z. THEN RAIN
OR A MIX OF RAIN AND SNOW WILL OCCUR IN THE WESTERN VALLEYS. MVFR TO
IFR CONDITIONS WILL BE COMMON OVER THE WEST THROUGH THE PERIOD.
PLEASE SEE INDIVIDUAL TERMINAL SITES FOR MORE DETAILS. EXPECT A
STRONG GUSTY WIND AT KRKS AIRPORT TUESDAY INTO TUESDAY EVENING.

&&

.FIRE WEATHER...

A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TUESDAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH TUESDAY AFTERNOON. A FEW SNOW SHOWERS
MAY DRIFT OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME. HIGH
PRESSURE AND DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS
ON WEDNESDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ001-002-008-009-014-024.

WINTER STORM WARNING FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ012.

HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY
WYZ003.

&&

$$

SHORT TERM...LIPSON
LONG TERM...CNJ
AVIATION...AR
FIRE WEATHER...LIPSON









000
FXUS63 KUNR 250500
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1000 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 958 PM MST MON NOV 24 2014

MOSTLY VFR CONDITIONS EXPECTED OVERNIGHT. ANOTHER ROUND OF SNOW
WILL OVERSPREAD THE REGION FROM NORTH TO SOUTH TUESDAY MRNG
BRINGING WDSPRD MVFR/IFR CONDITIONS. SOME LIFR CONDITIONS EXPECTED
ACRS NERN WY AND THE NRN BLKHLS. GUSTY W/NW WINDS EXPECTED TO
DEVELOP BY TUESDAY AFTERNOON.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON










000
FXUS63 KUNR 250500
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1000 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 958 PM MST MON NOV 24 2014

MOSTLY VFR CONDITIONS EXPECTED OVERNIGHT. ANOTHER ROUND OF SNOW
WILL OVERSPREAD THE REGION FROM NORTH TO SOUTH TUESDAY MRNG
BRINGING WDSPRD MVFR/IFR CONDITIONS. SOME LIFR CONDITIONS EXPECTED
ACRS NERN WY AND THE NRN BLKHLS. GUSTY W/NW WINDS EXPECTED TO
DEVELOP BY TUESDAY AFTERNOON.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON









000
FXUS65 KCYS 250027
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
527 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 526 PM MST MON NOV 24 2014

MAIN CONCERN WITH THIS TAF ISSUANCE IS WHEN THE SNOW SHOWERS WILL
DIMINISH AND WHEN WIND SPEEDS WILL PICKUP TOMORROW.

LATEST RADAR LOOP WAS SHOWING THE SNOW SHOWERS GRADUALLY
DISSIPATING. HOWEVER...THERE ARE STILL A FEW ROGUE SNOW SHOWERS
THAT ARE REDUCING THE VISIBILITY TO LESS THAN ONE HALF MILE AT
TIMES. THESE SNOW SHOWERS SHOULD CONTINUE TO DIMINISH THIS EVENING
BEFORE WIND SPEEDS START CRANKING UP OVERNIGHT STARTING AT RWL AND
LAR TAF SITES AFTER 09Z OR SO. THESE STRONG WINDS WILL THEN BEGIN
TO PUSH EAST TOWARDS AREAS EAST OF THE LARAMIE RANGE AFTER
DAYBREAK. NEXT UPPER LEVEL WAVE IS PROGGED TO MOVE INTO THE RWL
TAF SITE DURING THE AFTERNOON AND POSSIBLY BRING A CHANCE OF SNOW.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...RJM




000
FXUS65 KCYS 250027
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
527 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 526 PM MST MON NOV 24 2014

MAIN CONCERN WITH THIS TAF ISSUANCE IS WHEN THE SNOW SHOWERS WILL
DIMINISH AND WHEN WIND SPEEDS WILL PICKUP TOMORROW.

LATEST RADAR LOOP WAS SHOWING THE SNOW SHOWERS GRADUALLY
DISSIPATING. HOWEVER...THERE ARE STILL A FEW ROGUE SNOW SHOWERS
THAT ARE REDUCING THE VISIBILITY TO LESS THAN ONE HALF MILE AT
TIMES. THESE SNOW SHOWERS SHOULD CONTINUE TO DIMINISH THIS EVENING
BEFORE WIND SPEEDS START CRANKING UP OVERNIGHT STARTING AT RWL AND
LAR TAF SITES AFTER 09Z OR SO. THESE STRONG WINDS WILL THEN BEGIN
TO PUSH EAST TOWARDS AREAS EAST OF THE LARAMIE RANGE AFTER
DAYBREAK. NEXT UPPER LEVEL WAVE IS PROGGED TO MOVE INTO THE RWL
TAF SITE DURING THE AFTERNOON AND POSSIBLY BRING A CHANCE OF SNOW.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...RJM




000
FXUS65 KCYS 250027
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
527 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 526 PM MST MON NOV 24 2014

MAIN CONCERN WITH THIS TAF ISSUANCE IS WHEN THE SNOW SHOWERS WILL
DIMINISH AND WHEN WIND SPEEDS WILL PICKUP TOMORROW.

LATEST RADAR LOOP WAS SHOWING THE SNOW SHOWERS GRADUALLY
DISSIPATING. HOWEVER...THERE ARE STILL A FEW ROGUE SNOW SHOWERS
THAT ARE REDUCING THE VISIBILITY TO LESS THAN ONE HALF MILE AT
TIMES. THESE SNOW SHOWERS SHOULD CONTINUE TO DIMINISH THIS EVENING
BEFORE WIND SPEEDS START CRANKING UP OVERNIGHT STARTING AT RWL AND
LAR TAF SITES AFTER 09Z OR SO. THESE STRONG WINDS WILL THEN BEGIN
TO PUSH EAST TOWARDS AREAS EAST OF THE LARAMIE RANGE AFTER
DAYBREAK. NEXT UPPER LEVEL WAVE IS PROGGED TO MOVE INTO THE RWL
TAF SITE DURING THE AFTERNOON AND POSSIBLY BRING A CHANCE OF SNOW.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...RJM




000
FXUS65 KCYS 250027
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
527 PM MST MON NOV 24 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

RATHER VIGOROUS SNOW SHOWERS CONTINUE OVER THE A GOOD PORTION OF
THE CWA EARLY THIS EVENING AS A SHORTWAVE MOVES OVERHEAD IN THE
LFQ OF A STRONG JET. NEAR WHITEOUT CONDITIONS OCCURRED AT TIMES
THIS AFTERNOON IN THE HEAVY SHOWERS AND GUSTY CONVECTIVE
WINDS...WITH THIS ACTIVITY EXPECTED TO CONTINUE TO DIMINISH THIS
EVENING. SLICK AND SNOW COVERED ROADS ARE ANTICIPATED AS TEMPS
DROP TONIGHT AND FREEZE SNOW/ICE TO ROADS...ESPECIALLY I-25 AND
I-80 NEAR CHEYENNE...SO EXTREME CAUTION IS ADVISED IF TRAVELING
THROUGH THESE AREAS TONIGHT.

THE MAIN STORY FOR TUESDAY WILL BE STRONG WINDS AND CONTINUED
CHANCES FOR SNOW. THE 130 KT JET WILL MOVE OVER WYOMING TONIGHT
AND WILL SHIFT EAST INTO THE PANHANDLE THROUGH THE MORNING...ALL
THE WHILE INTENSIFYING ANOTHER 20 TO 30 KTS. STRONG MIDLEVEL
ENERGY COLLOCATED WITH THE JET WILL SLIDE SOUTHEAST ACROSS MONTANA
IN THE MORNING...AND INTO SOUTH DAKOTA/NEBRASKA LATE AFTERNOON AND
EVENING. AHEAD OF THE WAVE AND STRENGTHENING JET...THE LEESIDE
TROUGH WILL RAPIDLY DEEPEN LATE TONIGHT THROUGH TOMORROW
MORNING...WITH 800 - 700 MB WINDS INCREASING TO 50 TO 70 KTS
RESPECTIVELY BY SUNRISE...OR SHORTLY THEREAFTER. THE INVERSION
LOOKS TO SET UP NEAR MOUNTAIN TOP LEVEL IN THE MORNING...WITH
INCREASING SUBSIDENCE ALOFT AS THE RFQ OF THE JET THEN MOVES
OVERHEAD. THEREFORE EXPECT STRONG GRADIENT WINDS AND ACTIVE
MOUNTAIN WAVE GUSTS TO OCCUR FOR MANY AREAS ALONG AND WEST OF I-25
AND FOR EASTERN LARAMIE COUNTY IN THE MORNING AND AFTERNOON...AND
POSSIBLY THROUGH THE EVENING AS WELL. UPGRADED TO A HIGH WIND
WARNING FOR THESE AREAS AND TIMED IT SUCH THAT THE MORE WIND PRONE
AREAS FROM BORDEAUX...SOUTHERN LARAMIE RANGE AND
FOOTHILLS...ARLINGTON AND NORTHERN ALBANY/CARBON COUNTIES START
EARLIER IN THE MORNING AND END LATER TO CAPTURE MOUNTAIN WAVE AND
GAP INFLUENCES...WITH THE REMAINING ZONES EXPECTED TO SEE THE
STRONG WINDS TIED MORE TO DIURNAL MIXING TENDENCIES.

A RATHER STRONG COLD FRONT WILL DROP SOUTH ACROSS THE PLAINS LATE
TUESDAY AFTERNOON AND EVENING. MODELS SHOW SOME DIFFERENCES WITH
TIMING OF THIS FEATURE WITH THE GFS PERHAPS A BIT FASTER WITH THE
FRONT MOVING THROUGH AND STALLING ALONG THE LARAMIE RANGE SHORTLYAFTER
00Z. THIS WILL HAVE IMPLICATIONS FOR WHEN THE WINDS ACROSS THE
PLAINS WILL SHUT OFF...AND WHEN SNOW WILL DEVELOP ACROSS THIS
AREA. FOR NOW...HAVE WINDS DYING OFF IN THE EVENING WHILE
FRONTOGENESIS STRENGTHENS NW-SE ACROSS THE PLAINS AFTER 00Z
WEDNESDAY AND ON THRU THE NIGHT AS THE SFC FRONT STALLS ACROSS
THIS AREA. SO DO NOT FEEL THERE WILL BE A LONG PERIOD OVERLAP OF
WINDS AND SNOW ACROSS THE PLAINS...AND FEEL THE WIND HIGHLIGHT VS
WINTER HIGHLIGHT IS APPROPRIATE FOR NOW. HAVE 1 TO 3 INCHES OF
ACCUMULATION FOR MUCH OF THE PLAINS ALONG THE AXIS OF
FRONTOGENESIS...WITH THE JET SUBSIDENCE POSSIBLY ACTING AS A
LIMITING FACTOR FOR ADDITIONAL SNOW. WILL HAVE TO SEE WHETHER
HEAVY SNOW BANDS DO DEVELOP THO...AND WILL THEN NEED TO ENTERTAIN
HIGHER AMOUNTS AND PERHAPS WINTER HEADLINES FOR TUESDAY NIGHT
ACROSS THE PLAINS. FURTHER WEST...NOT EXPECTING AS MUCH WIDESPREAD
SNOWFALL IN THE HIGH VALLEYS WHERE WINDS WILL BE STRONGEST AS MOST
OF THE FORCING WILL BE TIED TO OROGRAPHICS. AGAIN FELT WIND VS
WINTER HIGHLIGHTS BEST FOR THESE AREAS AS WELL...BUT MENTIONED
BLOWING SNOW IN THE HIGH WIND WARNING STATEMENT FOR NOW.

REGARDING THE WINTER STORM WARNING FOR THE MOUNTAINS...DECIDED TO
JUST EXTEND THIS WARNING THROUGH TUESDAY NIGHT AS THE LULL IN
SNOW/WINDS TONIGHT WILL BE RELATIVELY SHORTLIVED WITH MORE HEAVY
SNOW FOR TOMORROW. LIKELY TO SEE A 12HR PERIOD OF MINIMAL SNOW IN
THE SNOWY AND SIERRA MADRES...BUT WITH WINDS RAPIDLY INCREASING
AROUND SUNRISE NEAR THE PEAKS AND RESTARTING THE SNOW
MACHINE...FELT IT BEST TO JUST KEEP THE WARNING GOING. OROGRAPHIC
SNOW SHOWERS WILL OCCUR THROUGH THE DAY AND MUCH OF THE NIGHT AS
STRONG WEST-SOUTHWEST MOUNTAIN TOP WINDS AND HIGH LLVL MOISTURE
PERSIST...WITH ANOTHER 4 TO 12 INCHES OF SNOW ACCUMULATION
EXPECTED OR PERHAPS HIGHER NEAR THE PEAKS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 526 PM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
POTENTIAL FOR THE LINGERING MORNING SNOWFALL IN AREAS EAST OF THE
LARAMIE RANGE WEDNESDAY MORNING FOLLOWED BY A WARM UP TOWARDS
THANKSGIVING WEEKEND.

WEDNESDAY-THURSDAY:
MODELS ARE ADVERTISING THE BAND OF 800-700MB FRONTOGENESIS
PERSISTING THROUGH MID MORNING IN RESPONSE TO A BAROCLINIC ZONE
SETTING UP BETWEEN CHEYENNE AND DOUGLAS WITH GOOD ISENTROPIC LIFT
BETWEEN 295-300K. BEYOND THAT TIME FRAME...SNOWFALL SHOULD COME TO
AND END BY MIDDAY WITH CONDITIONS IMPROVING AS THE LEE SIDE TROF
DEVELOPS. THIS LEE SIDE TROF WILL ALSO ALLOW FOR SOME SUBSIDENCE
TO KICK IN DURING THE AFTERNOON. AS A RESULT...WE SHOULD SEE WIND
SPEEDS INCREASE TO 40 TO 50 MPH MAINLY ALONG AND WEST OF THE
LARAMIE RANGE WITH HIGHER GUSTS POSSIBLE NEAR THE GAP REGIONS OF
ARLINGTON AND BORDEAUX. IN FACT...THE GFS/NAM ARE SHOWING 800MB
GRADIENTS AROUND 60 TO 65 METERS.

WEDNESDAY NIGHT-THURSDAY:
WIND SPEEDS WILL BE RELUCTANT TO DIMINISH DURING THE WEDNESDAY
NIGHT INTO THURSDAY TIMEFRAME. HOWEVER...THE SUBSIDENCE WILL BE
QUITE A BIT WEAKER WHICH MAY LIMIT MIXING SOMEWHAT THURSDAY. WE
MAY STILL HAVE TO DEAL WITH SOME GUSTY WINDS IN THE GAP
AREAS...BUT OVERALL THERE SHOULD BE A TREND TO SEE LIGHTER WIND
SPEEDS. TEMPERATURES ON THE OTHER HAND WILL CLIMB TO THE 40S AND
50S WITH GOOD DOWNSLOPE FLOW.

FRIDAY-MONDAY:
THE UPPER LEVEL PATTERN WILL CONTINUE TO FAVOR MILD CONDITIONS
INTO THE WEEKEND. HOWEVER...THE ECMWF IS SHOWING A FAIRLY STRONG
COLD FRONT MOVING THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THIS BOUNDARY MAY BRING A BAND OF SNOW ALONG WITH
IT. THE GFS IS NOT ADVERTISING AS COLD OF AIR AS THE ECMWF AT THIS
POINT. FOR NOW...WE WILL HAVE TO WATCH LATER RUNS TO SEE HOW THIS
PATTERN EVOLVES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 526 PM MST MON NOV 24 2014

MAIN CONCERN WITH THIS TAF ISSUANCE IS WHEN THE SNOW SHOWERS WILL
DIMINISH AND WHEN WIND SPEEDS WILL PICKUP TOMORROW.

LATEST RADAR LOOP WAS SHOWING THE SNOW SHOWERS GRADUALLY
DISSIPATING. HOWEVER...THERE ARE STILL A FEW ROGUE SNOW SHOWERS
THAT ARE REDUCING THE VISIBILITY TO LESS THAN ONE HALF MILE AT
TIMES. THESE SNOW SHOWERS SHOULD CONTINUE TO DIMINISH THIS EVENING
BEFORE WIND SPEEDS START CRANKING UP OVERNIGHT STARTING AT RWL AND
LAR TAF SITES AFTER 09Z OR SO. THESE STRONG WINDS WILL THEN BEGIN
TO PUSH EAST TOWARDS AREAS EAST OF THE LARAMIE RANGE AFTER
DAYBREAK. NEXT UPPER LEVEL WAVE IS PROGGED TO MOVE INTO THE RWL
TAF SITE DURING THE AFTERNOON AND POSSIBLY BRING A CHANCE OF SNOW.

&&

.FIRE WEATHER...
ISSUED AT 526 PM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES WILL REMAIN
BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.

     HIGH WIND WARNING FROM 3 AM TO 11 PM MST TUESDAY FOR WYZ104>106-
     109-110-116-117.

     HIGH WIND WARNING FROM 8 AM TO 7 PM MST TUESDAY FOR WYZ107-115-
     118-119.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...RJM




000
FXUS63 KUNR 242339
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
439 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 433 PM MST MON NOV 24 2014

-SHSN WILL CONTINUE TO DISSIPATE EARLY THIS EVENING. AREAS OF MVFR
CIGS AROUND THE BLKHLS WILL ALSO DISSIPATE THIS EVE WITH VFR
CONDITIONS EXPECTED OVERNIGHT. ANOTHER ROUND OF SNOW WILL
OVERSPREAD THE REGION FROM NORTH TO SOUTH TUESDAY MRNG BRINGING
WDSPRD MVFR/IFR CONDITIONS. SOME LIFR CONDITIONS EXPECTED ACRS
NERN WY AND THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON








000
FXUS63 KUNR 242339
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
439 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 433 PM MST MON NOV 24 2014

-SHSN WILL CONTINUE TO DISSIPATE EARLY THIS EVENING. AREAS OF MVFR
CIGS AROUND THE BLKHLS WILL ALSO DISSIPATE THIS EVE WITH VFR
CONDITIONS EXPECTED OVERNIGHT. ANOTHER ROUND OF SNOW WILL
OVERSPREAD THE REGION FROM NORTH TO SOUTH TUESDAY MRNG BRINGING
WDSPRD MVFR/IFR CONDITIONS. SOME LIFR CONDITIONS EXPECTED ACRS
NERN WY AND THE NRN BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON







000
FXUS65 KRIW 242306
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
406 PM MST MON NOV 24 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
A CLOCKWISE FLOW OF SUBTROPICAL PACIFIC MOISTURE WILL FLOW UP AND
OVER THE FLAT RIDGE OFF THE PACIFIC COAST INTO WYOMING LATER
TONIGHT THROUGH 12Z WEDNESDAY AS A TROUGH MAKING LANDFALL ONTO THE
BRITISH COLUMBIA COAST DRAGS THE MOISTURE INTO THE AREA. MAINLY
ADVISORY AMOUNTS ARE EXPECTED BUT DECIDED TO KEEP WARNING AMOUNTS
IN THE TETONS AS THIS NW FLOW IS A FAVORABLE FLOW PATTERN FOR
THOSE MTNS. DECIDED NOT TO ISSUE A WINTER WEATHER ADVISORY FOR
THE FAR WEST VALLEYS SINCE THE SNOW IS EXPECTED TO TURN TO RAIN BY
TUESDAY AFTERNOON WITH SNOW LEVELS EXPECTED TO LIFT TO 7K. VALLEY
RAIN SHOULD TURN BACK INTO SNOW TUESDAY NIGHT. THIS IS ALSO A
FAVORABLE FLOW PATTERN FOR THE BIG HORN MOUNTAINS GIVEN THE NW
FLOW AND THE AS CT VORT MAX TRACKING SOUTHEAST ACROSS THE NORTHERN
PLAINS. WENT WITH AN ADVISORY FOR THE BIG HORN MTNS DURING THE
SAME TIME FRAME AS WELL. SOME OF THE HEAVIEST SNOW IN THE HILITED
AREAS SHOULD TAKE PLACE TONIGHT WHEN THE MOST FAVORABLE DENTRITIC
GROWTH WILL TAKE PLACE AND WHEN THE JET STREAM WHICH WILL BE
OVERHEAD TONIGHT DRAWING IN MOISTURE FROM THE NW. ISENTROPIC LIFT
WILL HELP GET THE INITIAL STEADY LIGHT SNOWFALL UNDERWAY IN THE
BIG HORN MTNS INITIALLY. Q G FORCING WILL ALSO HELP ENHANCE THE
SNOWFALL FOR THE HILITED AREAS, THIS EVENT STILL APPEARS THAT IT
WILL PERSIST THROUGH 12Z WED.

AS FOR WIND...IT APPEARS THAT THE CODY FOOTHILLS...SPECIFICALLY
CLARK...WILL SEE A LOW END HIGH WIND WARNING BASED ON A 14C H7
TEMP SPREAD BETWEEN YNP AND THE CODY FOOTHILLS INITIATING GAP
FLOW. IN ADDITION...THE JET STREAM WILL BISECT THE CWA FROM SW TO
NE TONIGHT WHICH WILL PLACE THE RIGHT FRONT QUAD OF THE JET OVER
NORTHERN WY SURFACING THE H7 55 KNOT WINDS TO THE SURFACE. THERE
DOES NOT APPEAR TO BE A STRONG MTN WAVE SIGNATURE HOWEVER. CROSS SECTIONS
HAVE 50 KNOT WINDS CLOSE TO THE SURFACE NEAR CLARK. UPGRADED THE
HIGH WIND WATCH TO A WARNING FOR THE CODY FOOTHILLS FOR LATE
TONIGHT AND TUESDAY MORNING. WILL BE ISSUING A SPECIAL WEATHER STATEMENT
FOR STRONG SUB WARNING CRITERIA WINDS ANTICIPATED FROM RKS TO CPR
FOR TUESDAY GIVEN THE 55 KNOT H7 WINDS...RIGHT FRONT QUAD
DYNAMICS...6 DECAMETER H7 HEIGHT LINES SPACED APART EVERY 3
DECAMATERS ACROSS WY AS WELL AS 31 KNOT WINDS ON MOS GUIDANCE FOR
RKS. EXPECTING 30 TO 40 MPH WINDS WITH GUSTS TO 50 MPH ALONG THE
SOUTHERN WIND CORRIDOR TUE.

HIGH TEMPS WILL BE ABOVE FREEZING IN THE WESTERN VALLEYS TUE WITH
HIGHS IN THE LOW 40S EAST.

.LONG TERM...WEDNESDAY THROUGH MONDAY
GLOBAL FORECAST MODELS IN FAIRLY GOOD AGREEMENT THE THE VAST
MAJORITY OF THE EXTENDED PERIOD. NORTHWEST FLOW ALOFT PERSISTS
WEDNESDAY AS RIDGE PUSHES INLAND AND INTO THE GREAT BASIN. JET
ENERGY AND MOISTURE LIFTS SLOWLY NORTHEAST WEDNESDAY AS HEIGHTS
BUILD IN ASSOCIATION WITH WESTERN RIDGE. SNOW WILL LINGER LONGEST
IN THE NORTHWEST AND THE BIGHORN MOUNTAINS. BEST SUNSHINE AND
WARMER TEMPERATURES ARE MOST LIKELY OVER THE SOUTHWEST.
ALSO...GUSTY SOUTHWEST WINDS WILL AID WARMING ACROSS SWEETWATER
COUNTY AND SURROUNDING LOCALES. CONDITIONS ARE MAINLY DRY THEN
FROM WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS FLAT RIDGE
TRAVERSES THE FORECAST AREA. 700MB TEMPERATURES ON THANKSGIVING
ARE LIKELY TO BE 0C TO +2C. FULL MIXING WOULD PUT HIGH
TEMPERATURES AROUND 60F. HAVE AT LEAST NUDGED IN THAT DIRECTION
BUT MOST MODEL GUIDANCE IS TEMPERING THAT AMOUNT OF WARMING.
CAVEAT AT THIS TIME OF YEAR WILL BE THE AMOUNT OF MID- UPPER LEVEL
CLOUD COVER. BOTH MODELS SHOW A BIT OF A BREAK IN THE CLOUD COVER
THANKSGIVING AFTERNOON...BUT TIMING IS DIFFICULT WITHIN THE
PROGRESSIVE WESTERLY FLOW. MUCH THE SAME STORY EXPECTED FOR FRIDAY
AS WESTERLY FLOW STRENGTHENS AND TEMPERATURES CONTINUE TO
WARM...ESPECIALLY EAST OF THE CONTINENTAL DIVIDE. WARMEST HIGH
TEMPERATURES ON FRIDAY WILL BE IN EASTERN FOOTHILL LOCATIONS WHERE
INCREASING DOWNSLOPE WIND IS LIKELY. MOIST FLOW REACHES THE FAR
WEST FRIDAY AFTERNOON AND EVENING WITH PRECIPITATION BEGINNING
BEFORE 00Z/SAT. TEMPERATURES INITIALLY FAVOR RAIN IN THE JACKSON
AND STAR VALLEYS. DYNAMIC COOLING COUPLED WITH GRADUALLY COOLING
700MB TEMPERATURES WILL ALLOW RAIN TO CHANGE OVER TO SNOW EARLY
SATURDAY MORNING. SNOW WILL BE MORE WIDESPREAD WEST OF THE DIVIDE
FRIDAY NIGHT AND SATURDAY AS WITH POTENTIAL HIGHLIGHT SNOW AMOUNTS
BY 00Z/SUN. BEST AREAS FOR NOW WILL BE THE TETONS...TOGWOTEE...AND
THE HIGHER ELEVATIONS OF SOUTHERN YELLOWSTONE NATIONAL PARK.
EARLIER MODEL RUNS WERE TRYING TO DRIVE A COLD FRONT SOUTH ON
SATURDAY EAST OF THE CONTINENTAL DIVIDE. APPEARS THIS FEATURE WILL
NOT PUSH THROUGH UNTIL SATURDAY NIGHT IF AT ALL. UPPER FLOW
PARALLELS THIS FRONT AND MAY HINDER ITS SOUTHWARD PROGRESSION.
ALSO...SHORTWAVE ENERGY ACROSS SOUTHERN CANADA BECOMES ELONGATED
EAST-TO-WEST AND SHOWS LITTLE PUSH TO THE SOUTH. THEREFORE...COULD
EASILY IMAGINE THAT TEMPERATURES EAST OF THE DIVIDE COULD BE
WARMER THAN ADVERTISED AND FORECAST BASED ON THIS SCENARIO. SOME
WARMING ON MONDAY AS SOUTHWEST FLOW INCREASES AHEAD OF THE NEXT
WEATHER SYSTEM PUSHING INTO CALIFORNIA AND THE DESERT SOUTHWEST.
&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
THERE WILL BE SOME GENERAL DECREASE IN THE WIND THROUGH 03Z TUE
AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS ALONG THE
EAST SLOPES OF THE DIVIDE WITH SOME MOUNTAIN WAVE ACTIVITY LIKELY
ALONG WITH AREAS OF LLWS VCNTY KCOD- KDUB 3Z- 12Z TUESDAY.
IFR/MVFR CONDITIONS WILL DEVELOP LATER TONIGHT OVER THE BIG HORN MTNS.
WEST SOUTHWEST WINDS OF 25 TO 35 KNOTS WITH GUSTS TO 40 TO 45 KNOTS
ARE EXPECTED FROM THE RED DESERT TO KCPR TUE.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL VCNTY AND
NORTH OF A KPNA-KEMM LINE FROM 08Z THROUGH TUESDAY EVENING WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD. SNOW WILL TURN TO RAIN IN THE WESTERN VALLEYS
INCLUDING KAFO AND KJAC. WEST SOUTHWEST WINDS OF 25 TO 35 NOTS WITH
GUSTS TO 40 TO 45 KNOTS ARE EXPECTED IN SWEETWATER COUNTY
INCLUDING THE VCNTY OF KRKS.

&&

.FIRE WEATHER...
A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TUESDAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH TUESDAY AFTERNOON. A FEW SNOW SHOWERS
MAY DRIFT OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME. HIGH
PRESSURE AND DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS
ON WEDNESDAY.


&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ001-002-008-009-014-024.

WINTER STORM WARNING FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ012.

HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY
WYZ003.

&&

$$

SHORT TERM...LIPSON
LONG TERM...CNJ
AVIATION...LIPSON
FIRE WEATHER...LIPSON





000
FXUS65 KRIW 242306
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
406 PM MST MON NOV 24 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
A CLOCKWISE FLOW OF SUBTROPICAL PACIFIC MOISTURE WILL FLOW UP AND
OVER THE FLAT RIDGE OFF THE PACIFIC COAST INTO WYOMING LATER
TONIGHT THROUGH 12Z WEDNESDAY AS A TROUGH MAKING LANDFALL ONTO THE
BRITISH COLUMBIA COAST DRAGS THE MOISTURE INTO THE AREA. MAINLY
ADVISORY AMOUNTS ARE EXPECTED BUT DECIDED TO KEEP WARNING AMOUNTS
IN THE TETONS AS THIS NW FLOW IS A FAVORABLE FLOW PATTERN FOR
THOSE MTNS. DECIDED NOT TO ISSUE A WINTER WEATHER ADVISORY FOR
THE FAR WEST VALLEYS SINCE THE SNOW IS EXPECTED TO TURN TO RAIN BY
TUESDAY AFTERNOON WITH SNOW LEVELS EXPECTED TO LIFT TO 7K. VALLEY
RAIN SHOULD TURN BACK INTO SNOW TUESDAY NIGHT. THIS IS ALSO A
FAVORABLE FLOW PATTERN FOR THE BIG HORN MOUNTAINS GIVEN THE NW
FLOW AND THE AS CT VORT MAX TRACKING SOUTHEAST ACROSS THE NORTHERN
PLAINS. WENT WITH AN ADVISORY FOR THE BIG HORN MTNS DURING THE
SAME TIME FRAME AS WELL. SOME OF THE HEAVIEST SNOW IN THE HILITED
AREAS SHOULD TAKE PLACE TONIGHT WHEN THE MOST FAVORABLE DENTRITIC
GROWTH WILL TAKE PLACE AND WHEN THE JET STREAM WHICH WILL BE
OVERHEAD TONIGHT DRAWING IN MOISTURE FROM THE NW. ISENTROPIC LIFT
WILL HELP GET THE INITIAL STEADY LIGHT SNOWFALL UNDERWAY IN THE
BIG HORN MTNS INITIALLY. Q G FORCING WILL ALSO HELP ENHANCE THE
SNOWFALL FOR THE HILITED AREAS, THIS EVENT STILL APPEARS THAT IT
WILL PERSIST THROUGH 12Z WED.

AS FOR WIND...IT APPEARS THAT THE CODY FOOTHILLS...SPECIFICALLY
CLARK...WILL SEE A LOW END HIGH WIND WARNING BASED ON A 14C H7
TEMP SPREAD BETWEEN YNP AND THE CODY FOOTHILLS INITIATING GAP
FLOW. IN ADDITION...THE JET STREAM WILL BISECT THE CWA FROM SW TO
NE TONIGHT WHICH WILL PLACE THE RIGHT FRONT QUAD OF THE JET OVER
NORTHERN WY SURFACING THE H7 55 KNOT WINDS TO THE SURFACE. THERE
DOES NOT APPEAR TO BE A STRONG MTN WAVE SIGNATURE HOWEVER. CROSS SECTIONS
HAVE 50 KNOT WINDS CLOSE TO THE SURFACE NEAR CLARK. UPGRADED THE
HIGH WIND WATCH TO A WARNING FOR THE CODY FOOTHILLS FOR LATE
TONIGHT AND TUESDAY MORNING. WILL BE ISSUING A SPECIAL WEATHER STATEMENT
FOR STRONG SUB WARNING CRITERIA WINDS ANTICIPATED FROM RKS TO CPR
FOR TUESDAY GIVEN THE 55 KNOT H7 WINDS...RIGHT FRONT QUAD
DYNAMICS...6 DECAMETER H7 HEIGHT LINES SPACED APART EVERY 3
DECAMATERS ACROSS WY AS WELL AS 31 KNOT WINDS ON MOS GUIDANCE FOR
RKS. EXPECTING 30 TO 40 MPH WINDS WITH GUSTS TO 50 MPH ALONG THE
SOUTHERN WIND CORRIDOR TUE.

HIGH TEMPS WILL BE ABOVE FREEZING IN THE WESTERN VALLEYS TUE WITH
HIGHS IN THE LOW 40S EAST.

.LONG TERM...WEDNESDAY THROUGH MONDAY
GLOBAL FORECAST MODELS IN FAIRLY GOOD AGREEMENT THE THE VAST
MAJORITY OF THE EXTENDED PERIOD. NORTHWEST FLOW ALOFT PERSISTS
WEDNESDAY AS RIDGE PUSHES INLAND AND INTO THE GREAT BASIN. JET
ENERGY AND MOISTURE LIFTS SLOWLY NORTHEAST WEDNESDAY AS HEIGHTS
BUILD IN ASSOCIATION WITH WESTERN RIDGE. SNOW WILL LINGER LONGEST
IN THE NORTHWEST AND THE BIGHORN MOUNTAINS. BEST SUNSHINE AND
WARMER TEMPERATURES ARE MOST LIKELY OVER THE SOUTHWEST.
ALSO...GUSTY SOUTHWEST WINDS WILL AID WARMING ACROSS SWEETWATER
COUNTY AND SURROUNDING LOCALES. CONDITIONS ARE MAINLY DRY THEN
FROM WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS FLAT RIDGE
TRAVERSES THE FORECAST AREA. 700MB TEMPERATURES ON THANKSGIVING
ARE LIKELY TO BE 0C TO +2C. FULL MIXING WOULD PUT HIGH
TEMPERATURES AROUND 60F. HAVE AT LEAST NUDGED IN THAT DIRECTION
BUT MOST MODEL GUIDANCE IS TEMPERING THAT AMOUNT OF WARMING.
CAVEAT AT THIS TIME OF YEAR WILL BE THE AMOUNT OF MID- UPPER LEVEL
CLOUD COVER. BOTH MODELS SHOW A BIT OF A BREAK IN THE CLOUD COVER
THANKSGIVING AFTERNOON...BUT TIMING IS DIFFICULT WITHIN THE
PROGRESSIVE WESTERLY FLOW. MUCH THE SAME STORY EXPECTED FOR FRIDAY
AS WESTERLY FLOW STRENGTHENS AND TEMPERATURES CONTINUE TO
WARM...ESPECIALLY EAST OF THE CONTINENTAL DIVIDE. WARMEST HIGH
TEMPERATURES ON FRIDAY WILL BE IN EASTERN FOOTHILL LOCATIONS WHERE
INCREASING DOWNSLOPE WIND IS LIKELY. MOIST FLOW REACHES THE FAR
WEST FRIDAY AFTERNOON AND EVENING WITH PRECIPITATION BEGINNING
BEFORE 00Z/SAT. TEMPERATURES INITIALLY FAVOR RAIN IN THE JACKSON
AND STAR VALLEYS. DYNAMIC COOLING COUPLED WITH GRADUALLY COOLING
700MB TEMPERATURES WILL ALLOW RAIN TO CHANGE OVER TO SNOW EARLY
SATURDAY MORNING. SNOW WILL BE MORE WIDESPREAD WEST OF THE DIVIDE
FRIDAY NIGHT AND SATURDAY AS WITH POTENTIAL HIGHLIGHT SNOW AMOUNTS
BY 00Z/SUN. BEST AREAS FOR NOW WILL BE THE TETONS...TOGWOTEE...AND
THE HIGHER ELEVATIONS OF SOUTHERN YELLOWSTONE NATIONAL PARK.
EARLIER MODEL RUNS WERE TRYING TO DRIVE A COLD FRONT SOUTH ON
SATURDAY EAST OF THE CONTINENTAL DIVIDE. APPEARS THIS FEATURE WILL
NOT PUSH THROUGH UNTIL SATURDAY NIGHT IF AT ALL. UPPER FLOW
PARALLELS THIS FRONT AND MAY HINDER ITS SOUTHWARD PROGRESSION.
ALSO...SHORTWAVE ENERGY ACROSS SOUTHERN CANADA BECOMES ELONGATED
EAST-TO-WEST AND SHOWS LITTLE PUSH TO THE SOUTH. THEREFORE...COULD
EASILY IMAGINE THAT TEMPERATURES EAST OF THE DIVIDE COULD BE
WARMER THAN ADVERTISED AND FORECAST BASED ON THIS SCENARIO. SOME
WARMING ON MONDAY AS SOUTHWEST FLOW INCREASES AHEAD OF THE NEXT
WEATHER SYSTEM PUSHING INTO CALIFORNIA AND THE DESERT SOUTHWEST.
&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
THERE WILL BE SOME GENERAL DECREASE IN THE WIND THROUGH 03Z TUE
AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS ALONG THE
EAST SLOPES OF THE DIVIDE WITH SOME MOUNTAIN WAVE ACTIVITY LIKELY
ALONG WITH AREAS OF LLWS VCNTY KCOD- KDUB 3Z- 12Z TUESDAY.
IFR/MVFR CONDITIONS WILL DEVELOP LATER TONIGHT OVER THE BIG HORN MTNS.
WEST SOUTHWEST WINDS OF 25 TO 35 KNOTS WITH GUSTS TO 40 TO 45 KNOTS
ARE EXPECTED FROM THE RED DESERT TO KCPR TUE.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL VCNTY AND
NORTH OF A KPNA-KEMM LINE FROM 08Z THROUGH TUESDAY EVENING WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD. SNOW WILL TURN TO RAIN IN THE WESTERN VALLEYS
INCLUDING KAFO AND KJAC. WEST SOUTHWEST WINDS OF 25 TO 35 NOTS WITH
GUSTS TO 40 TO 45 KNOTS ARE EXPECTED IN SWEETWATER COUNTY
INCLUDING THE VCNTY OF KRKS.

&&

.FIRE WEATHER...
A MOIST NORTHWEST FLOW WILL RESULT IN SNOW AND STRONG WIND FOR MOST
MOUNTAIN RANGES THROUGH TUESDAY. THESE CONDITIONS WILL KEEP FIRE
WEATHER IMPACTS TO A MINIMUM. THE SAME LOW IMPACT APPLIES TO THE
LOWER ELEVATIONS OF WEST CENTRAL WYOMING...ALTHOUGH GUSTY SURFACE
WIND REMAINS POSSIBLE THROUGH TUESDAY AFTERNOON. A FEW SNOW SHOWERS
MAY DRIFT OFF THE HIGHER TERRAIN OR FOOTHILLS DURING THIS TIME. HIGH
PRESSURE AND DRIER/WARMER WEATHER CAN BE EXPECTED FOR FIRE DISTRICTS
ON WEDNESDAY.


&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ001-002-008-009-014-024.

WINTER STORM WARNING FROM 2 AM TUESDAY TO 5 AM MST WEDNESDAY
WYZ012.

HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY
WYZ003.

&&

$$

SHORT TERM...LIPSON
LONG TERM...CNJ
AVIATION...LIPSON
FIRE WEATHER...LIPSON






000
FXUS63 KUNR 242036
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
136 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY
ISSUED AT 131 PM MST MON NOV 24 2014

SNOW SHOWERS WILL CONTINUE OVER NORTHEAST WYOMING...THE BLACK
HILLS...AND PORTIONS OF WESTERN SD THROUGH THE AFTERNOON. SNOW
WILL DIMINISH THIS EVENING...LASTING LONGEST OVER THE BLACK HILLS.
MVFR CIGS/VSBY EXPECTED WITH SNOW SHOWERS...WITH LOCAL IFR
CONDITIONS. BREEZY NORTHWEST WINDS ARE EXPECTED TODAY...AND WILL
GRADUALLY WEAKEN AND TURN SOUTHWESTERLY TONIGHT. NOT RECEIVING OBS
FROM GCC SO AN AMENDMENT IS NOT SCHEDULED.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.

&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...POJORLIE





000
FXUS63 KUNR 242036
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
136 PM MST MON NOV 24 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 131 PM MST MON NOV 24 2014

A MODERATE TO HEAVY BAND OF SNOW CONTINUED ACROSS THE NRN-ERN
SLOPES OF THE BLKHLS AND ADJACENT AREAS EARLY THIS AFTN. THIS
APPEARS TO BE THE RESULT OF LOW-LEVEL FRONTOGENESIS AND VERY STEEP
LAPSE RATES AS A WEAK SHORT-WAVE TROUGH WAS MOVING THROUGH THE
AREA. THIS SNOW SHOULD GRADUALLY SHIFT SOUTHEAST THIS AFTN AND
WEAKEN RAPIDLY THIS EVNG AS THE TROUGH EXITS THE AREA. HOWEVER...
SOME LIGHT UPSLOPE SNOW MAY LINGER THROUGH THE EVNG.

FOR THE REST OF THE NIGHT...NORTHWEST FLOW AND WARM ADVECTION ALOFT
WILL ENSUE AS THE NEXT...STRONGER...SHORT-WAVE TROUGH MOVES TOWARD
THE AREA FROM BRITISH COLUMBIA. THIS WILL SPREAD HIGH CLOUDS ACROSS
THE CWA LATE TONIGHT...AND ALSO SWITCH THE BLYR WINDS TO SOUTHWEST.
THIS WARMER AND DRIER AIR ALOFT WILL SHUT OFF THE UPSLOPE SNOWS.

ON TUESDAY...THE SHORT-WAVE TROUGH WILL MOVE TO WRN SD DURING THE
DAY...SPREADING WIDESPREAD CLOUDS AND SHOWERS ACROSS THE AREA. GIVEN
THE WARMING PROFILES THERE MAY BE A MIX OF RAIN AND SNOW ACROSS MUCH
OF THE PLAINS...WITH AT LEAST 1-3 INCHES OF SNOW LIKELY ACROSS THE
NRN BLKHLS AGAIN AS FAVORABLE UPSLOPE CONDITIONS RESUME. NORTHWEST
WINDS WILL INCREASE OVER NWRN SD DURING THE DAY AND MAY LEAD TO
SOME REDUCED VSBYS WITH THE SNOW SHOWERS.

ON TUESDAY NGT...THE WAVE MOVES SOUTHEAST WITH SNOW DIMINISHING
ACROSS MUCH OF THE AREA...BUT LINGERING ACROSS NERN WY WHERE MOIST
UPSLOPE FLOW WILL CONTINUE.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 131 PM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN PLAINS
WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO THE ERN
CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY...
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM
CNTRL MT TO ERN WY AND FAR WRN SD. SNOW ACCUMULATION IS EXPECTED
TO BE LITTLE...AN INCH OR LESS OVER MOST LOCATIONS. GFS/ECMWF
STILL AGREEING ON A WARMER AND DRY SOLUTION FOR THANKSGIVING INTO
EARLY SATURDAY. RAISED TEMPS FOR THURSDAY...WITH HIGHS RANGING
FROM NEAR 30 OVER NW SD TO MID 40S OVER PORTIONS OF NE WY/SW
SD...ALTHOUGH MAX TEMPS WILL BE TRICKY DEPENDING ON THE POSITION
OF THE WARM FRONT. ALSO RAISED TEMPS FOR FRIDAY...WITH HIGHS IN
THE 40S TO LOWER 50S. MODELS CONTINUE TO SHOW A COLD FRONT
CROSSING THE CWA SATURDAY WITH LIGHT PRECIP ACCOMPANYING IT.
COOLER TEMPS WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY
ISSUED AT 131 PM MST MON NOV 24 2014

SNOW SHOWERS WILL CONTINUE OVER NORTHEAST WYOMING...THE BLACK
HILLS...AND PORTIONS OF WESTERN SD THROUGH THE AFTERNOON. SNOW
WILL DIMINISH THIS EVENING...LASTING LONGEST OVER THE BLACK HILLS.
MVFR CIGS/VSBY EXPECTED WITH SNOW SHOWERS...WITH LOCAL IFR
CONDITIONS. BREEZY NORTHWEST WINDS ARE EXPECTED TODAY...AND WILL
GRADUALLY WEAKEN AND TURN SOUTHWESTERLY TONIGHT. NOT RECEIVING OBS
FROM GCC SO AN AMENDMENT IS NOT SCHEDULED.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.

&&

$$

SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...POJORLIE






000
FXUS65 KRIW 241952
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1255 PM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
DRIER AIR WILL PUSH NW-SE BEHIND THIS MORNINGS WEATHER SYSTEM.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
DRIER AIR WILL PUSH INTO THE NW BEHIND THIS MORNINGS WEATHER SYSTEM
WITH OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE
TO CAUSE OCNL MVFR VSBY VCNTY KJAC.  GUSTY NW SFC WINDS WILL FOLLOW
THE SYSTEM THROUGH MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN
RIVER BASIN AND INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL
BRING INCREASING SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE
08Z-12Z TUESDAY WITH WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED
BY 12Z ALONG WITH MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM/LIPSON
FIRE WEATHER...HATTINGS










000
FXUS65 KRIW 241952
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1255 PM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
DRIER AIR WILL PUSH NW-SE BEHIND THIS MORNINGS WEATHER SYSTEM.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
DRIER AIR WILL PUSH INTO THE NW BEHIND THIS MORNINGS WEATHER SYSTEM
WITH OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE
TO CAUSE OCNL MVFR VSBY VCNTY KJAC.  GUSTY NW SFC WINDS WILL FOLLOW
THE SYSTEM THROUGH MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN
RIVER BASIN AND INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL
BRING INCREASING SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE
08Z-12Z TUESDAY WITH WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED
BY 12Z ALONG WITH MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM/LIPSON
FIRE WEATHER...HATTINGS










000
FXUS65 KRIW 241952
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1255 PM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
DRIER AIR WILL PUSH NW-SE BEHIND THIS MORNINGS WEATHER SYSTEM.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
DRIER AIR WILL PUSH INTO THE NW BEHIND THIS MORNINGS WEATHER SYSTEM
WITH OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE
TO CAUSE OCNL MVFR VSBY VCNTY KJAC.  GUSTY NW SFC WINDS WILL FOLLOW
THE SYSTEM THROUGH MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN
RIVER BASIN AND INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL
BRING INCREASING SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE
08Z-12Z TUESDAY WITH WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED
BY 12Z ALONG WITH MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM/LIPSON
FIRE WEATHER...HATTINGS










000
FXUS65 KRIW 241952
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1255 PM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
DRIER AIR WILL PUSH NW-SE BEHIND THIS MORNINGS WEATHER SYSTEM.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
DRIER AIR WILL PUSH INTO THE NW BEHIND THIS MORNINGS WEATHER SYSTEM
WITH OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE
TO CAUSE OCNL MVFR VSBY VCNTY KJAC.  GUSTY NW SFC WINDS WILL FOLLOW
THE SYSTEM THROUGH MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN
RIVER BASIN AND INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL
BRING INCREASING SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE
08Z-12Z TUESDAY WITH WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED
BY 12Z ALONG WITH MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM/LIPSON
FIRE WEATHER...HATTINGS










000
FXUS65 KCYS 241759
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1059 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1044 AM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS FORECAST IS WHICH TAF SITES WILL GET
IMPACTED BY THE SNOW SHOWERS THIS AFTERNOON.

LATEST RADAR LOOP WAS SHOWING A BAND OF SNOW JUST NORTH OF
CHEYENNE WITH ANOTHER BAND OF SNOW JUST NORTH OF CHADRON. NOT
CONFIDENT THAT THE CHEYENNE TAF SITE WILL SEE MUCH IMPACT FROM THE
SNOWFALL AT THE TAF SITE. HOWEVER...YOU WILL NOT HAVE FLY TOO FAR
EAST BEFORE THE VISIBILITY WILL DROP BELOW 1 MILE AND CEILINGS
DROP TO BELOW 1KFT FOR AN HOUR OR TWO MEANWHILE...CHADRON TAF
SITE MAY SEE THE CEILINGS/VISIBILITY DROP INTO THE IFR CATEGORY
DURING THE NEXT COUPLE OF HOURS. OTHERWISE...VFR CONDITIONS WILL
BE THE RULE THIS AFTERNOON WITH GUSTY WEST TO NORTHWEST WINDS.
WIND SPEEDS WILL DIMINISH SOMEWHAT THIS EVENING...BUT SHOULD
PICKUP QUICKLY TOMORROW AS THE STRONG JET ENERGY AND BETTER
SUBSIDENCE MOVES INTO THE PICTURE.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.
&&

$$

SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...REC
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 241759
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1059 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1044 AM MST MON NOV 24 2014

THE MAIN CONCERN WITH THIS FORECAST IS WHICH TAF SITES WILL GET
IMPACTED BY THE SNOW SHOWERS THIS AFTERNOON.

LATEST RADAR LOOP WAS SHOWING A BAND OF SNOW JUST NORTH OF
CHEYENNE WITH ANOTHER BAND OF SNOW JUST NORTH OF CHADRON. NOT
CONFIDENT THAT THE CHEYENNE TAF SITE WILL SEE MUCH IMPACT FROM THE
SNOWFALL AT THE TAF SITE. HOWEVER...YOU WILL NOT HAVE FLY TOO FAR
EAST BEFORE THE VISIBILITY WILL DROP BELOW 1 MILE AND CEILINGS
DROP TO BELOW 1KFT FOR AN HOUR OR TWO MEANWHILE...CHADRON TAF
SITE MAY SEE THE CEILINGS/VISIBILITY DROP INTO THE IFR CATEGORY
DURING THE NEXT COUPLE OF HOURS. OTHERWISE...VFR CONDITIONS WILL
BE THE RULE THIS AFTERNOON WITH GUSTY WEST TO NORTHWEST WINDS.
WIND SPEEDS WILL DIMINISH SOMEWHAT THIS EVENING...BUT SHOULD
PICKUP QUICKLY TOMORROW AS THE STRONG JET ENERGY AND BETTER
SUBSIDENCE MOVES INTO THE PICTURE.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.
&&

$$

SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...REC
FIRE WEATHER...RUBIN




000
FXUS63 KUNR 241709
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1009 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY
ISSUED AT 1008 AM MST MON NOV 24 2014

LIGHT SNOW SHOWERS WILL CONTINUE OVER NORTHEAST
WYOMING...THE BLACK HILLS...AND PORTIONS OF WESTERN SD THROUGH THE
AFTERNOON. SNOW WILL DIMINISH THIS EVENING...LASTING LONGEST OVER
THE BLACK HILLS. MVFR CIGS/VSBY EXPECTED WITH SNOW SHOWERS...WITH
LOCAL IFR CONDITIONS. BREEZY NORTHWEST WINDS ARE EXPECTED
TODAY...AND WILL GRADUALLY WEAKEN AND TURN SOUTHWESTERLY TONIGHT.
NOT RECEIVING OBS FROM GCC SO AN AMENDMENT IS NOT SCHEDULED.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE






000
FXUS63 KUNR 241709
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1009 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY
ISSUED AT 1008 AM MST MON NOV 24 2014

LIGHT SNOW SHOWERS WILL CONTINUE OVER NORTHEAST
WYOMING...THE BLACK HILLS...AND PORTIONS OF WESTERN SD THROUGH THE
AFTERNOON. SNOW WILL DIMINISH THIS EVENING...LASTING LONGEST OVER
THE BLACK HILLS. MVFR CIGS/VSBY EXPECTED WITH SNOW SHOWERS...WITH
LOCAL IFR CONDITIONS. BREEZY NORTHWEST WINDS ARE EXPECTED
TODAY...AND WILL GRADUALLY WEAKEN AND TURN SOUTHWESTERLY TONIGHT.
NOT RECEIVING OBS FROM GCC SO AN AMENDMENT IS NOT SCHEDULED.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE







000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 241611
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
911 AM MST MON NOV 24 2014

.UPDATE...
ISSUED AT 906 AM MST MON NOV 24 2014

HAVE UPDATED THE SHORT-TERM FORECAST TO BOOST POPS OVER THE BLACK
HILLS AREA AND ALSO TO INCREASE SNOW AMOUNTS. THE FORECAST
SOUNDINGS SHOW STEEP LAPSE RATES...A VERY MOIST PROFILE...AND
NORTHWEST WINDS OF 25-35 KT IN THE BLYR TODAY. THIS SHOULD LEAD TO
EFFICIENT UPSLOPE SNOW THAT ALSO WILL SPILL OVER INTO THE RAPID
CITY AREA. DRYING AND WARMING ALOFT IS EXPECTED THIS EVENING AS
THE SHORT-WAVE TROUGH PASSES...AND THAT SHOULD BRING A BRIEF
RESPITE FROM THE SNOW SHOWERS.

&&

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORTWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND MVFR/LCL IFR
CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL IMPROVE TO VFR
TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS WILL BE
POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED TODAY...AND
WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...BUNKERS
SHORT TERM...10
LONG TERM...13
AVIATION...13







000
FXUS65 KRIW 241251
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
551 AM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS







000
FXUS65 KRIW 241251
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
551 AM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS







000
FXUS65 KRIW 241251
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
551 AM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS







000
FXUS65 KRIW 241251
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
551 AM MST MON NOV 24 2014

.UPDATE...
CONTINUES TO LOOK VERY INTERESTING FOR THE NW MOUNTAINS AND
SURROUNDING AREA FOR HEAVY SNOW BEGINNING LATER TONIGHT THROUGH
TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE PATTERN IS PRODUCING SOME
PRETTY IMPRESSIVE TIME HEIGHTS IN THE NW. DENDRITIC GROWTH ZONE
TEMPERATURES DO GET A LITTLE WARM WITH TIME BUT IT`S HARD TO
IGNORE THE 30-50KT MTN TOP FLOW AND STEADY PCPN FOR 24 HOURS OR
MORE. WILL KEY IN ON THE FAVORED WNW FLOW AREAS WITH OTHER AREAS
LIKELY NEEDING ADVISORIES WITH THE AFTERNOON PACKAGE. THERE WILL
BE POTENTIAL FOR A CHANGEOVER TO RAIN OR RAIN AND SNOW BY LATE
TUESDAY OR TUESDAY NIGHT...ESPECIALLY IN THE STAR VALLEY. UPDATE
GOING OUT ASAP.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
WYZ012-013.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS







000
FXUS65 KCYS 241203
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
503 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 503 AM MST MON NOV 24 2014

A WEATHER DISTURBANCE WILL DIVE SOUTHEAST ACROSS THE REGION TODAY.
ITS PASSAGE WILL CARRY TWO IMPACTS ON THIS SET OF TAFS.
FIRSTLY...EXPECT PERIDIC SNOW SHOWERS TO DEVELOP OVER THE AREA.
THESE SHOULD BE PRETTY BRIEF IN DURATION...BUT MAY DROP CONDITIONS
TO MVFR. CONFIDENCE IS THE HIGHEST OF THIS OCCURING AT KLAR THRU
16Z. SNOW SHOWERS WILL HAVE A MORE DIFFICULT AT SITES EAST OF THE
MOUNTAINS. ALTHOUGH SNOW SHOWERS WILL STILL BE POSSIBLE...AM NOT
CONFIDENT IN TIMING AND LOCATION TO INCLUDE ANYTHING MORE THAN
VCSH. SHOULD SEE A PERIOD OF MVFR CIGS THO 16-01Z EAST OF THE
MOUNTAINS. DISTURBANCE WILL DRIFT SOUTH OF THE AREA BY THIS
EVENING...THUS EXPECT CONDITIONS TO IMPROVE AFTER 00Z. NORTHWEST
WINDS WILL AGAIN BECOME BREEZY TODAY WITH GUSTS OF 25-35 KNOTS
COMMON.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.

&&

$$

SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 241203
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
503 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 503 AM MST MON NOV 24 2014

A WEATHER DISTURBANCE WILL DIVE SOUTHEAST ACROSS THE REGION TODAY.
ITS PASSAGE WILL CARRY TWO IMPACTS ON THIS SET OF TAFS.
FIRSTLY...EXPECT PERIDIC SNOW SHOWERS TO DEVELOP OVER THE AREA.
THESE SHOULD BE PRETTY BRIEF IN DURATION...BUT MAY DROP CONDITIONS
TO MVFR. CONFIDENCE IS THE HIGHEST OF THIS OCCURING AT KLAR THRU
16Z. SNOW SHOWERS WILL HAVE A MORE DIFFICULT AT SITES EAST OF THE
MOUNTAINS. ALTHOUGH SNOW SHOWERS WILL STILL BE POSSIBLE...AM NOT
CONFIDENT IN TIMING AND LOCATION TO INCLUDE ANYTHING MORE THAN
VCSH. SHOULD SEE A PERIOD OF MVFR CIGS THO 16-01Z EAST OF THE
MOUNTAINS. DISTURBANCE WILL DRIFT SOUTH OF THE AREA BY THIS
EVENING...THUS EXPECT CONDITIONS TO IMPROVE AFTER 00Z. NORTHWEST
WINDS WILL AGAIN BECOME BREEZY TODAY WITH GUSTS OF 25-35 KNOTS
COMMON.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.

&&

$$

SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 241103
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
403 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 925 PM MST SUN NOV 23 2014

NORTHWEST WINDS WILL REMAIN BREEZY FOR THE PLAINS TONIGHT...WITH
STRONGER AND GUSTY WEST WINDS DEVELOPING FROM THE LARAMIE RANGE
WESTWARD. A UPPER LEVEL DISTURBANCE WILL BRING THE STRONGER WINDS
AND INCREASE THE SNOW INTENSITY OVER THE SOUTHERN WY MOUNTAINS
WITH LIFR OBSCURATIONS. MVFR CEILINGS/VISIBILITIES WILL BE
POSSIBLE OUTSIDE THE MOUNTAINS WEST OF THE LARAMIE RANGE INCLUDING
RAWLINS AND SARATOGA. WEST TO NORTHWEST WINDS WILL REMAIN BREEZY
TO WINDY MONDAY WITH OCCASIONAL SNOW SHOWERS AFFECTING SOUTHEAST
WY AND NORTHERN NE PANHANDLE TERMINALS.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.

&&

$$

SHORT TERM...SAR
LONG TERM...CAH
AVIATION...MJ
FIRE WEATHER...SAR



000
FXUS65 KCYS 241103
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
403 AM MST MON NOV 24 2014

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 350 AM MST MON NOV 24 2014

TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY...AIDING IN THE
OROGRAPHIC SNOWS TO CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES...SO WILL CONTINUE THE WINTER STORM WARNING THERE.  WITH
MOIST FLOW ALOFT...A FEW OTHER SNOW SHOWERS MAY OCCUR OUTSIDE THE
MOUNTAINS. BREEZY DAY PER PROGGED GRADIENTS.

TONIGHT...WINDS WILL REALLY START TO CRANK UP AFTER MIDNIGHT AS A
STRONG JET MOVES OVERHEAD AND THE SURFACE THROUGH 700 MB GRADIENTS
STRENGTHEN SIGNIFICANTLY. IN FACT...THE CRAIG TO CASPER HEIGHT
GRADIENTS WILL CLIMB OVER 60 METERS AND THUS HAVE ISSUED A HIGH WIND
WATCH STARTING LATE.

TUESDAY...VERY STRONG WINDS ALOFT AND WITH A JET MOVING OVERHEAD AND
PROGGED SURFACE THROUGH 700 MB GRADIENTS...A HIGH WIND EVENT LOOKS
QUITE LIKELY ACROSS MUCH OF SOUTHEAST WYOMING. CASPER TO CRAIG
HEIGHT GRADIENTS ARE WELL OVER 60 METERS...QUITE SUGGESTIVE OF A
LIKELY HIGH WIND EVENT.

TUESDAY NIGHT...BRISK AND MOIST OROGRAPHIC FLOW CONTINUES WITH THE
MAIN BULK OF THE OROGRAPHICS OVER THE SNOWY AND SIERRA MADRE
RANGES...ALONG WITH AREAS OF BLOWING SNOW. CONTINUED QUITE WINDY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 350 AM MST MON NOV 24 2014

MEDIUM RANGE GUIDANCE HAS FINALLY CONVERGED ON SIMILAR SOLUTIONS
FOR THE UPCOMING HOLIDAY...WHICH NOW LOOKS TO BE DRY AND MILD.
NORTHWEST FLOW WILL BE IN PLACE ON WED WITH THE JET SHIFTING EAST
TOWARDS THE MID-MISSISSIPPI RIVER VALLEY. ANOTHER BREEZY DAY
ANTICIPATED ON WED FOR AREAS ALONG AND WEST OF I-25. RESIDUAL
SNOW SHOWERS MAY LINGER DURING THE MORNING HOURS ALONG A COLD
FRONT WHICH WILL BE QUICKLY RETREATING EAST DURING THE DAYLIGHT
HOURS. LITTLE OR NO ADDITIONAL ACCUMULATIONS ARE EXPECTED
WEDNESDAY MORNING. LEFT INHERITED BLOWING SNOW GOING FOR AREAS IN
AND AROUND THE MOUNTAINS WED MORNING. THIS WILL DEPEND UPON JUST
HOW MUCH SNOW FALLS TUESDAY NT. THE PATTERN FLATTENS FOR
THANKSGIVING DAY AND FRIDAY WITH FLOW TURNING MORE ZONAL. AT THE
SFC...A DEVELOPING LEE SIDE PRESSURE TROUGH WILL AND RESULTANT
WESTERLY DOWNSLOPE WINDS WILL BOOST HIGH TEMPS INTO THE 50S EAST
OF THE LARAMIE RANGE WITH 40S WEST BOTH DAYS. BREEZY CONDITIONS
CAN BE EXPECTED THU-SAT WITH GUSTS OF 25 TO 35 MPH. MODELS HINT
AT A COLD FRONT BRIEFLY DROPPING SOUTH SATURDAY AFTERNOON AND
SATURDAY NIGHT. THIS WOULD COOL TEMPERATURES SOME SUNDAY
ESPECIALLY OVR NRN ZONES. 00Z GFS SUGGEST PERHAPS SOME LT SNOW MAY
ACCOMPANY THE FRONT DGW-CDR SATURDAY NT. THIS IS UNSUPPORTED BY
THE 00Z ECMWF...SO FOR NOW HAVE KEPT THE FORECAST DRY BOTH SATURDAY
AND SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 925 PM MST SUN NOV 23 2014

NORTHWEST WINDS WILL REMAIN BREEZY FOR THE PLAINS TONIGHT...WITH
STRONGER AND GUSTY WEST WINDS DEVELOPING FROM THE LARAMIE RANGE
WESTWARD. A UPPER LEVEL DISTURBANCE WILL BRING THE STRONGER WINDS
AND INCREASE THE SNOW INTENSITY OVER THE SOUTHERN WY MOUNTAINS
WITH LIFR OBSCURATIONS. MVFR CEILINGS/VISIBILITIES WILL BE
POSSIBLE OUTSIDE THE MOUNTAINS WEST OF THE LARAMIE RANGE INCLUDING
RAWLINS AND SARATOGA. WEST TO NORTHWEST WINDS WILL REMAIN BREEZY
TO WINDY MONDAY WITH OCCASIONAL SNOW SHOWERS AFFECTING SOUTHEAST
WY AND NORTHERN NE PANHANDLE TERMINALS.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MST MON NOV 24 2014

THOUGH WINDS WILL BE STRONG AT TIMES...HUMIDITIES
WILL REMAIN BELOW CRITICAL THRESHOLDS...SO NO FIRE WEATHER CONCERNS
ARE ANTICIPATED.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
     114.

     HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
     WYZ103>107-109-110-114>119.

NE...NONE.

&&

$$

SHORT TERM...SAR
LONG TERM...CAH
AVIATION...MJ
FIRE WEATHER...SAR




000
FXUS63 KUNR 241049
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
349 AM MST MON NOV 24 2014

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND
MVFR/LCL IFR CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL
IMPROVE TO VFR TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS
WILL BE POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED
TODAY...AND WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...13







000
FXUS63 KUNR 241049
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
349 AM MST MON NOV 24 2014

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 316 AM MST MON NOV 24 2014

FAST NORTHWEST FLOW ALOFT WILL BRING A FEW SHORTWAVES ACROSS THE
REGION OVER THE NEXT COUPLE OF DAYS. THE FIRST SHORTWAVE...CURRENTLY
LOCATED OVER ERN MONTANA WILL AFFECT MAINLY THE WESTERN PART OF
THE FORECAST AREA TODAY. THE MAIN REGION OF FORCING WILL REMAIN
WELL SOUTHWEST OF THE FORECAST AREA. HOWEVER...ENOUGH UPPER LEVEL
SUPPORT WILL BE IN PLACE FOR UPSLOPE SNOW WITH RELATIVELY STEEP LL
LAPSE RATES AND 20-30 KNOTS OF FLOW IN INCREASING MOISTURE. THIS
WILL SUPPORT A DECENT SETUP FOR SNOW SHOWERS WITH SOME ACCUMS IN
THE NORTHERN BLACK HILLS...WITH GENERALLY 1 TO 3 INCHES
POSSIBLE...MAINLY FROM THE BEAR LODGE MOUNTAINS TO AROUND CHEYENNE
CROSSING. ANY SNOW ACCUMS OUTSIDE OF THE BLACK HILLS OVER
NORTHEASTERN WYOMING WILL BE AN INCH OR LESS. BREEZY CONDITIONS
CAN BE EXPECTED ACROSS THE ENTIRE REGION...STRONGEST OVER NE WY
GIVEN PRESSURE RISE/FALL COUPLET WITH THE PASSING IMPULSE. THE
CHANCE OF SNOW SHOWERS WILL LINGER INTO THE EVENING OVER THE
NORTHERN BLACK HILLS AND FAR NORTHWESTERN SOUTH DAKOTA. A STRONGER
SHORTWAVE WILL CROSS THE AREA ON TUESDAY AS SYNOPTIC SCALE
DIVERGENCE INCREASES WITH A JET STREAK MOVING INTO THE REGION FROM
THE NORTHWEST. THERE WILL BE A CHANCE OF SNOW SHOWERS ACROSS MUCH
OF THE AREA ON TUESDAY. BREEZY TO WINDY CONDITIONS WILL DEVELOP ON
TUESDAY AS A SFC LOW DROPS SOUTHWARD ACROSS NORTH DAKOTA AND
TIGHTENS THE SFC PRESSURE GRADIENT. THE TIMING OF THE SHORTWAVES
ON TUE/WED DIFFERS SOMEWHAT FROM PREVIOUS MODEL RUNS. THERE MAY BE A
DRY PERIOD ON TUESDAY NIGHT BEFORE THE NEXT SHORWAVE MOVES IN ON
WEDNESDAY. HAVE KEPT THE SNOW IN ON TUESDAY NIGHT FOR
NOW...WAITING FOR SOME CONSISTENCY IN THE TIMING TO SHOW IN THE
LATER MODEL RUNS.

&&

.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 316 AM MST MON NOV 24 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE ACROSS THE NRN
PLAINS WEDNESDAY AS THE UPPER TROUGH FINALLY BEGINS TO SLIDE INTO
THE ERN CONUS. CHANCES FOR SNOW WILL CONTINUE THROUGH THE DAY
CONCENTRATED ALONG A DRIFTING BAROCLINIC ZONE STRETCHING FROM CNTRL
MT TO ERN WY. SNOW ACCUMULATION IS EXPECTED TO BE LITTLE...AN INCH
OR LESS OVER MOST LOCATIONS. GFS/ECMWF FINALLY COMING INTO DECENT
AGREEMENT WITH FOR THE THANKSGIVING HOLIDAY AND INTO THE WEEKEND.
THE WARMER SOLUTION HAS WON OUT. IT LOOKS LIKE WARMER AIR WILL
ADVECT IN WED NIGHT INTO THUR BRINGING DRY WEATHER AS THE SNOW
SLIDES NORTH INTO ND/ERN MT. MAX TEMPS WILL BE TRICKY DEPENDING ON
THE POSITION OF THE WARM FRONT...WITH HIGHS RANGING FROM THE MID 20S
OVER NW SD TO LOWER 40S OVER PORTIONS OF NE WY/SW SD. THE PREVIOUS
COLDER THANKSGIVING DAY SOLUTIONS HAD HIGHS STRUGGLING THROUGH THE
TEENS WITH SOME SNOW FALLING. DRY WARMER WEATHER WILL CONTINUE INTO
FRIDAY WITH HIGHS IN THE UPPER 30S TO UPPER 40S. THE GOOD MODEL
AGREEMENT CONTINUES INTO THE WEEKEND WITH A COLD FRONT CROSSING THE
CWA SATURDAY WITH VERY LIGHT PRECIP ACCOMPANYING IT. COOLER TEMPS
WILL THEN REMAIN THROUGH SUNDAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 316 AM MST MON NOV 24 2014

THE NEXT DISTURBANCE WILL BRING CHANCES OF -SN AND
MVFR/LCL IFR CIGS TO NE WY INTO THE BLKHLS AREA. CONDITIONS WILL
IMPROVE TO VFR TONIGHT AS SN DIMINISHES...BUT SOME LINGER MVFR CIGS
WILL BE POSSIBLE NEAR THE BLKHLS. BREEZY NW WINDS ARE EXPECTED
TODAY...AND WILL GRADUALLY WEAKEN THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...13






000
FXUS65 KRIW 241007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
307 AM MST MON NOV 24 2014

.SHORT TERM...MONDAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.


.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.
&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS









000
FXUS65 KRIW 241007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
307 AM MST MON NOV 24 2014

.SHORT TERM...MONDAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.


.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.
&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS










000
FXUS65 KRIW 241007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
307 AM MST MON NOV 24 2014

.SHORT TERM...MONDAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.


.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.
&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS









000
FXUS65 KRIW 241007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
307 AM MST MON NOV 24 2014

.SHORT TERM...MONDAY THROUGH WEDNESDAY NIGHT

WITH THE DIFFERENCES IN THE WEATHER ACROSS THE AREA...ONE AGAIN WE
WILL SPLIT THINGS UP WITH THE CONTINENTAL DIVIDE AS THE SPLIT.

WEST OF THE DIVIDE...YET ANOTHER IN THE SERIES OF SHORTWAVES
CONTINUES TO MOVE THROUGH THE STATE. A DECENT BAND OF SNOW HAS
DEVELOPED IN IDAHO AND IS NOW DROPPING SOUTHWARD ACROSS THE WEST. IT
COULD BRING A QUICK INCH OR TWO TO SOME LOCATIONS. THE GOOD NEWS IS
THAT IT IS MOVING SOUTH AT A DECENT CLIP AT THIS TIME SO IT SHOULD
MOVE THROUGH FAIRLY QUICKLY. THE SNOW SHOULD TAPER OFF FAIRLY
QUICKLY TOWARD MORNING THOUGH. TODAY WILL BE A PERIOD IN BETWEEN
SYSTEMS SO HEAVY SNOW IS NOT EXPECTED. HOWEVER...WITH NORTHWEST FLOW
CONTINUING THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS THROUGH
THE DAY. THE NEXT SYSTEM...THIS ONE WITH A LITTLE MORE PUNCH WILL
MOVE TOWARD THE AREA TONIGHT. THE MODELS STILL HAVE SOME DIFFERENCES
IN TIMING WITH THE NAM A BIT SLOWER THAN THE OTHER MODELS. FOR
NOW...WE STARTED WITH LOW POPS AND RAMPED THEM UP THROUGH THE NIGHT
AND INTO TUESDAY. THIS SYSTEM DOES HAVE SOME DECENT LIFT WITH SOME
WARM ADVECTION AS WELL. SOME HIGHLIGHTS ARE ANTICIPATED WITH THIS
SYSTEM. HOWEVER...THE MODELS HAVE BEEN OVERDOING THE QPF WITH THESE
SHORTWAVES THE PAST WEEK OR SO. SO ALTHOUGH WE DID INCREASE SNOWFALL
AMOUNTS...WE KEPT THEM BELOW WARNING CRITERIA. SOME ADVISORIES WILL
PROBABLY BE NEEDED TO BE ISSUED LATER TODAY HOWEVER. THIS SNOW WILL
CONTINUE THROUGH TUESDAY NIGHT AS WELL. CONDITIONS SHOULD BEGIN TO
IMPROVE WEDNESDAY MORNING AS THE SYSTEM MOVES AWAY AND RIDGING
BEGINS TO BUILD ACROSS WYOMING. THE MODELS HAVE BEGUN TO COME INTO
BETTER AGREEMENT WITH RIDGING CONTINUING TO BUILD ACROSS THE STATE
LATER WEDNESDAY AND INTO WEDNESDAY NIGHT. AS A RESULT...WE HAVE
TRIMMED POPS FOR LATER WEDNESDAY AND WEDNESDAY NIGHT. WITH THE
RECENT DIFFERENCES IN THE MODELS...WE DID NOT REMOVE THEM YET AND
WOULD PREFER TO WAIT ANOTHER RUN OR TWO TO DRY THINGS OUT
COMPLETELY.

EAST OF THE DIVIDE...THE RADAR IS SHOWING SOME ECHOES ACROSS THE
AREA. HOWEVER...ALL OF THIS ACTIVITY HAS NOT REACHED THE GROUND YET
WITH THE DRY ATMOSPHERE IN PLACE. WITH THE SHORTWAVE MOVING THROUGH
THE AREA...EXPECT ANOTHER BREEZY TO WINDY DAY FOR MANY AREAS. OF
PARTICULAR CONCERN ARE AREAS ACROSS SWEETWATER COUNTY WHERE 700
MILLIBAR WINDS ARE APPROACHING 50 TO 55 KNOTS LATE TONIGHT.
HOWEVER...AT THIS TIME WE DO NOT THINK WINDS THIS STRONG WILL MIX TO
THE SURFACE. THERE COULD BE SOME GUSTS TO 50 MPH HOWEVER. WINDS
SHOULD GRADUALLY DECREASE THROUGH THE AFTERNOON AS WINDS ALOFT RELAX
A BIT. AS FOR THE CHANCE OF PRECIPITATION...BOTH THE NAM AND GFS
SHOW SOME LIGHT PRECIPITATION OCCURRING FROM THE EASTERN BIG HORN
BASIN DOWN THROUGH EASTERN FREMONT AND EASTERN SWEETWATER COUNTIES
AND EASTWARD. FURTHER WEST...WITH DOWNSLOPING FLOW MOST AREAS SHOULD
STAY DRY. PRECIPITATION AMOUNTS STILL LOOK FAIRLY LIGHT THOUGH. THE
MOUNTAINS COULD SEE A COUPLE OF INCHES HOWEVER.

FOR TONIGHT...ATTENTION TURNS TOWARD THE CHANCE OF HIGH WINDS ACROSS
FAVORED AREAS IN THE ABSAROKAS AND CODY FOOTHILLS...INCLUDING THE
CROSSROADS OF AMERICA...CLARK. 700 MILLIBAR WINDS ARE EXPECTED TO
INCREASE TO 60 TO 65 KNOTS BY EARLY TUESDAY MORNING. IN
ADDITION...BY EARLY TUESDAY MORNING THE AREA WILL BE IN THE FAVORED
RIGHT FRONT QUAD OF THE JET TO PROVIDE SOME DOWNWARD FORCING. SO AS
A RESULT WE WILL CONTINUE THE HIGH WIND WATCH. THE NEXT QUESTION IS
HOW MUCH PRECIPITATION WILL MAKE IT OVER THE DIVIDE FOR TUESDAY AND
TUESDAY NIGHT.  THE MODELS ARE IN FAR AGREEMENT IN THE AREA BEING
MAINLY ACROSS PORTIONS OF THE BIG HORN BASIN...ESPECIALLY IN THE
EAST AND TO THE EAST AS WELL AS NORTH OF THE OWL CREEK RANGE. WITH
THE FAVORED NORTHWEST FLOW...THE BIGHORN MOUNTAINS COULD DO
PARTICULARLY WELL WITH THIS SETUP. HOWEVER...EVEN THE LOWER
ELEVATIONS COULD SEE A FEW INCHES OF SNOW. THERE IS STILL SOME
DISAGREEMENT IN THE DETAILS HOWEVER. THE NEXT CONCERN IS FOR WIND.
THE MODELS CONTINUE TO SHOW SOME VERY STRONG WINDS ALOFT WITH 50 TO
60 KNOTS AT 700 MILLIBARS ACROSS MUCH OF THE AREA. HOWEVER...ONE
NEGATIVE IS THAT CLOUD COVER MAY HELP TO LIMIT MIXING...ESPECIALLY
WITH THE STRONGEST WINDS EXPECTED AT NIGHT. THE EXCEPTION ONCE AGAIN
MAY BE AREAS NEAR CLARK...BUT WE WILL CROSS THAT BRIDGE TOMORROW.
CONDITIONS SHOULD ONCE AGAIN IMPROVE ON WEDNESDAY AS THE SYSTEM
LIFTS OUT. AND...LIKE WHAT WAS STATED IN WEST OF THE DIVIDE...THE
MODELS HAVE TRENDED TOWARD RIDGING FOR WEDNESDAY AND WEDNESDAY NIGHT
AND MAINLY DRY BUT WINDY CONDITIONS FOR WEDNESDAY NIGHT.


.LONG TERM...THURSDAY THROUGH MONDAY

GFS SEEMS TO BE ON A WINNING STREAK THE PAST FEW SYSTEMS WITH BOTH
THE ECMWF...GEM AND ECMWF ENSEMBLES NOW FOLLOWING THE GFS LEAD WITH
OUR THANKSGIVING WEEKEND WEATHER SYSTEMS. A DRAMATIC TURN FROM LAST
NIGHT WHEN THE GFS WAS AN OUTLIER. END RESULT IS A MUCH MILDER
THURSDAY/FRIDAY BEFORE WE FINALLY GET A COLD FRONT FROM THE NORTH
FRIDAY NIGHT INTO SATURDAY. SHOULD GET SOME DECENT SNOW ACROSS THE
WEST IN THE MOIST...SAGGING WLY FLOW FRIDAY INTO SATURDAY. HOW MUCH
IF ANY WE GET EAST OF THE DIVIDE IS STILL UNCERTAIN...ESPECIALLY
AFTER THE WAY THE MODELS HAVE STRUGGLED THE PAST FEW DAYS.
ALTHOUGH...THEY HAVE GENERALLY BEEN PICKING UP ON THIS FRIDAY NIGHT/
SATURDAY SYSTEM FOR A WHILE IT WAS JUST THE INITIAL SHORTWAVE ON
THANKSGIVING THAT THEY`VE BEEN STRUGGLING WITH. IT NOW APPEARS THIS
WAVE WILL WEAKEN IN THE CONFLUENT FLOW AND INFLUENCE OF WARM AIR
BEING PUMPED UP AHEAD OF THE NEW ERN PACIFIC UPPER LOW. SO BOTTOM
LINE...IT LOOKS LIKE A NICE THANKSGIVING DAY NOW WITH SNOW MOVING
INTO THE WRN MOUNTAINS MAINLY LATER FRIDAY OR FRIDAY EVENING...
CONTINUING THROUGH SATURDAY. VALLEYS COULD BE RAIN OR RAIN AND SNOW
MIX INITIALLY...ESPECIALLY THE STAR VALLEY WITH H7 TEMPERATURES
STARTING AS WARM AS -1C AT H7 ONLY NOT COOLING SIGNIFICANTLY UNTIL
FRIDAY NIGHT AND SATURDAY. WINDS WILL ALSO BE ON THE INCREASE
THANKSGIVING DAY INTO FRIDAY WITH POTENTIAL FOR SOME HIGH WINDS BY
FRIDAY IN THE WIND CORRIDOR AND CODY FOOTHILLS. MAYBE AS EARLY AS
THURSDAY NIGHT IN THE CODY FOOTHILLS. COLDER EAST OF THE DIVIDE
SATURDAY WITH SHORTWAVE PASSING OFF TO THE EAST BUT PUSHING A
DECENT SURFACE HIGH AND ASSOCIATED COLD FRONT SWD INTO AREAS EAST
OF THE DIVIDE. ON SUNDAY...HEIGHTS START TO BUILD AS STRONG
PACIFIC SYSTEM STARTS TO MOVE ONTO THE WEST COAST WITH WARMING MID
LEVEL TEMPERATURES AND POTENTIAL FOR LIGHT MOUNTAIN SNOW OUT WEST.
SNOW WILL LIKELY BE ON THE INCREASE MONDAY AS TROUGH MOVES INTO
THE GREAT BASIN AND INTER-MOUNTAIN WEST. EAST OF THE
DIVIDE...WE`LL HAVE TO WATCH THIS EVOLUTION CLOSELY COLD AIR WILL
BE LURKING JUST TO THE NORTH AND SURFACE LOW MAY DEVELOP OVER SRN
WYO OR NRN CO AT THE END OF THIS PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO PUSH SE
ACROSS WYOMING EARLY THIS MORNING SPREADING AREAS OF LIGHT SNOW AND
FRQT MTN OBSCURATIONS ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF
MVFR -SN MAINLY VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH
15Z.  DRIER AIR WILL PUSH NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.
GUSTY NW SFC WINDS WILL CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY
KDUB-KRIW AND EAST OF THE BIGHORN RANGE.  THERE WILL BE SOME
DECREASE IN THE WIND 21Z MON-03Z TUE AND THEN RIDGE TOP WEST WINDS
WILL INCREASE TO 40-50KTS ALONG THE EAST SLOPES OF THE DIVIDE WITH
MOUNTAIN WAVE ACTIVITY LIKELY ALONG WITH AREAS OF LLWS VCNTY
KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL CONTINUE TO DIVE SE ALONG
THE DIVIDE EARLY THIS MORNING WITH AREAS OF MVFR/IFR -SN AND
WIDESPREAD MTN OBSCURATIONS SHIFTING INTO SW WY THROUGH 15Z.  DRIER
AIR WILL PUSH INTO THE NW BEHIND THE SYSTEM EARLY THIS MORNING WITH
OVERALL IMPROVING CONDITIONS...THOUGH GUSTY WINDS WILL CONTINUE TO
CAUSE OCNL MVFR VSBY VCNTY KJAC.  MOST OF THE MVFR/IFR -SN WILL EXIT
SW WY BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH
MONDAY AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND
INTERSTATE 80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING
SNOWFALL VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH
WIDESPREAD MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH
MTNS MOSTLY OBSCD.
&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA THIS MORNING. THE NORTHERN AND WESTERN MOUNTAINS
WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW WILL MAKE IT TO THE
VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE IF ANY SNOWFALL IS
EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON. RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN
THE AFTERNOON EAST OF THE CONTINENTAL DIVIDE. ANOTHER MORE POTENT
SYSTEM WILL BRING MORE SNOW TO THE WEST STARTING LATER MONDAY NIGHT.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING
WYZ002-003.

&&

$$

SHORT TERM...HATTINGS
LONG TERM...SKRBAC
AVIATION...AEM
FIRE WEATHER...HATTINGS










000
FXUS65 KRIW 240635
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1131 PM MST SUN NOV 23 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH MONDAY (ISSUED AT 308 PM MST)

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE LOW SPINNING OVER SOUTHWEST ALASKA WILL EJECT ANOTHER SHORTWAVE
TROUGH THAT WILL EVENTUALLY TRACK SOUTHEAST IN THE FORM OF AN
ALBERTA CLIPPER ACROSS THE NORTHERN PLAINS BY TUE.. AS A
RESULT...THE ON GOING LIGHT SNOWFALL OVER THE FAR WEST BEING FED BY
A MOIST PACIFIC NORTHWEST FLOW WILL BECOME ENHANCED AS THIS WEATHER
FEATURE DRAWS CLOSER. SNOWFALL WILL CONTINUE TO INCREASE IN THE WEST
TUESDAY AND CONTINUE TUESDAY NIGHT. SNOWFALL WILL SPREAD INTO
NORTHERN WY EAST OF THE DIVIDE TUESDAY AS ISENTROPIC LIFT...Q VECTOR
FORCING AND THE NORTHEAST PROGRESSION OF THE JET ACROSS THE CWA
ENHANCES THE PULL OF PACIFIC MOISTURE FROM THE NORTHWEST. THE
SNOWFALL WILL CONTINUE IN NORTHERN WY THROUGH TUESDAY NIGHT.
SNOWFALL WILL END WEDNESDAY AS THE SYSTEM PULLS TO THE SOUTHEAST.
SNOWFALL AMOUNTS WITH THIS SYSTEM WILL LIKELY AMOUNT TO 3 TO 6
INCHES IN THE WESTERN MTNS...1 TO 3 INCHES IN THE WESTERN VALLEYS
AND 3 TO 9 INCHES IN THE BIG HORN MTNS. MOST OF THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL HAVE LITTLE IF ANY ACCUMULATION.

THE OTHER CONCERN WITH THIS PARTICULAR WEATHER FEATURE IS WIND. H7
WIND WIND SPEEDS ARE PROJECTED TO INCREASE TO AT LEAST 55 KNOTS LATE
TUESDAY NIGHT AND INTO WEDNESDAY MORNING OVER NORTHERN...CENTRAL AND
EASTERN WY. IN ADDITION...MTN WAVE POTENTIAL CANNOT BE RULED OUT
WITH A FROUDE NUMBER OF 1 NEAR CLARK ALONG WITH A BACKING WIND WITH
TIME. HOWEVER...FAVORABLE MTN TOP INVERSIONS APPEAR TO BE LACKING.
ANOTHER FAVORABLE MARKER ARE 6 DECAMETER HEIGHT LINES SPACED APART
EVERY 3 DECAMETERS OVER WY TUESDAY NIGHT. HAVE INDICATED BORDERLINE
HIGH WIND CRITERIA IN THE GRIDS FOR NOW FROM 03Z WED THROUGH 21Z WED
WITH THE STRONG WIND POTENTIAL FOR THE CODY FOOTHILLS TUE NT/WED AND
FRO THE SOUTHERN WIND CORRIDOR MAINLY ON WED. THE EAST SLOPE OF THE
WIND RIVER...ABSAROKA AND BIG HORN MTNS WILL EXPERIENCE CONSIDERABLE
BLOWING SNOW DURING THIS EVENT.

FOR THANKSGIVING DAY...THE EURO AND THE GFS APPEAR...AT LEAST FOR
NOW...TO BE MORE IN AGREEMENT THEN PAST RUNS WITH THE IDEA OF A
FLATTENING RIDGE FOR THURSDAY WITH THE NEXT SHORTWAVE WAVE THAT HAS
BEEN IN QUESTION FINALLY COMING INTO PLAY FRIDAY. HAVE KEPT HIGHER CHANCES
OF SNOW IN THE NORTHERN MTNS FOR THU TO TAKE INTO ACCOUNT THE
UNCERTAINTY OF WHAT THE NORTHERN STREAM ENERGY MAY HAVE IN STORE FOR
US. THEN INCREASED POPS IN NW WY FOR SNOW FRIDAY WITH THAT DELAYED
SHORTWAVE WAVE. HAVE SNOW INCREASING IN THE WEST SATURDAY GIVEN THE
TROUPHPA AND WEAK ISENTROPIC LIFT. THEN WITH THE WARM AIR
ADVECTION/ISENTROPIC LIFT...KEPT IDEA OF SPREADING SOME OF THE SNOW
TO AREAS EAST OF THE DIVIDE SUNDAY. IF ITS ANY CONSOLATION...BOTH
THE GFS AND THE EURO AGREE ON THE FACT THAT A COL REGION WILL SHOW
UP OFF THE PAC NW COAST WHICH WOULD AT LEAST...IF NOTHING ELSE...ADD
CREDIBILITY TO THE LONG TERM SOLNS OF BOTH MODELS.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES A FAST-MOVING
UPPER LEVEL DISTURBANCE WILL PUSH SE ACROSS WYOMING EARLY MONDAY
MORNING SPREADING AREAS OF LIGHT SNOW AND FRQT MTN OBSCURATIONS
ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF MVFR -SN MAINLY VCNTY
AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH 15Z.  DRIER AIR WILL PUSH
NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.  GUSTY NW SFC WINDS WILL
CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY KDUB-KRIW AND EAST OF
THE BIGHORN RANGE.  THERE WILL BE SOME DECREASE IN THE WIND 21Z
MON-03Z TUE AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS
ALONG THE EAST SLOPES OF THE DIVIDE WITH MOUNTAIN WAVE ACTIVITY
LIKELY ALONG WITH AREAS OF LLWS VCNTY KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL DIVE SE ALONG THE DIVIDE
EARLY MONDAY MORNING WITH WIDESPREAD MVFR...AREAS OF IFR -SN BLSN
EXPECTED TO CONTINUE THROUGH 10Z...PUSHING INTO SW WY...VCNTY
KPNA-KBPI-KRKS 9Z-15Z.  DRIER AIR WILL PUSH INTO NW WYOMING AFTER
10Z BEHIND THIS SYSTEM...WITH MOST OF THE MVFR/IFR -SN EXITING SW WY
BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH MONDAY
AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND INTERSTATE
80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL
VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH WIDESPREAD
MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH MTNS MOSTLY
OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.  RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN THE
AFTERNOON EAST OF THE CONTINENTAL DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...HIGH WIND WATCH FROM MONDAY
EVENING THROUGH TUESDAY MORNING WYZ002-003.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...AEM
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 240635
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1131 PM MST SUN NOV 23 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH MONDAY (ISSUED AT 308 PM MST)

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE LOW SPINNING OVER SOUTHWEST ALASKA WILL EJECT ANOTHER SHORTWAVE
TROUGH THAT WILL EVENTUALLY TRACK SOUTHEAST IN THE FORM OF AN
ALBERTA CLIPPER ACROSS THE NORTHERN PLAINS BY TUE.. AS A
RESULT...THE ON GOING LIGHT SNOWFALL OVER THE FAR WEST BEING FED BY
A MOIST PACIFIC NORTHWEST FLOW WILL BECOME ENHANCED AS THIS WEATHER
FEATURE DRAWS CLOSER. SNOWFALL WILL CONTINUE TO INCREASE IN THE WEST
TUESDAY AND CONTINUE TUESDAY NIGHT. SNOWFALL WILL SPREAD INTO
NORTHERN WY EAST OF THE DIVIDE TUESDAY AS ISENTROPIC LIFT...Q VECTOR
FORCING AND THE NORTHEAST PROGRESSION OF THE JET ACROSS THE CWA
ENHANCES THE PULL OF PACIFIC MOISTURE FROM THE NORTHWEST. THE
SNOWFALL WILL CONTINUE IN NORTHERN WY THROUGH TUESDAY NIGHT.
SNOWFALL WILL END WEDNESDAY AS THE SYSTEM PULLS TO THE SOUTHEAST.
SNOWFALL AMOUNTS WITH THIS SYSTEM WILL LIKELY AMOUNT TO 3 TO 6
INCHES IN THE WESTERN MTNS...1 TO 3 INCHES IN THE WESTERN VALLEYS
AND 3 TO 9 INCHES IN THE BIG HORN MTNS. MOST OF THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL HAVE LITTLE IF ANY ACCUMULATION.

THE OTHER CONCERN WITH THIS PARTICULAR WEATHER FEATURE IS WIND. H7
WIND WIND SPEEDS ARE PROJECTED TO INCREASE TO AT LEAST 55 KNOTS LATE
TUESDAY NIGHT AND INTO WEDNESDAY MORNING OVER NORTHERN...CENTRAL AND
EASTERN WY. IN ADDITION...MTN WAVE POTENTIAL CANNOT BE RULED OUT
WITH A FROUDE NUMBER OF 1 NEAR CLARK ALONG WITH A BACKING WIND WITH
TIME. HOWEVER...FAVORABLE MTN TOP INVERSIONS APPEAR TO BE LACKING.
ANOTHER FAVORABLE MARKER ARE 6 DECAMETER HEIGHT LINES SPACED APART
EVERY 3 DECAMETERS OVER WY TUESDAY NIGHT. HAVE INDICATED BORDERLINE
HIGH WIND CRITERIA IN THE GRIDS FOR NOW FROM 03Z WED THROUGH 21Z WED
WITH THE STRONG WIND POTENTIAL FOR THE CODY FOOTHILLS TUE NT/WED AND
FRO THE SOUTHERN WIND CORRIDOR MAINLY ON WED. THE EAST SLOPE OF THE
WIND RIVER...ABSAROKA AND BIG HORN MTNS WILL EXPERIENCE CONSIDERABLE
BLOWING SNOW DURING THIS EVENT.

FOR THANKSGIVING DAY...THE EURO AND THE GFS APPEAR...AT LEAST FOR
NOW...TO BE MORE IN AGREEMENT THEN PAST RUNS WITH THE IDEA OF A
FLATTENING RIDGE FOR THURSDAY WITH THE NEXT SHORTWAVE WAVE THAT HAS
BEEN IN QUESTION FINALLY COMING INTO PLAY FRIDAY. HAVE KEPT HIGHER CHANCES
OF SNOW IN THE NORTHERN MTNS FOR THU TO TAKE INTO ACCOUNT THE
UNCERTAINTY OF WHAT THE NORTHERN STREAM ENERGY MAY HAVE IN STORE FOR
US. THEN INCREASED POPS IN NW WY FOR SNOW FRIDAY WITH THAT DELAYED
SHORTWAVE WAVE. HAVE SNOW INCREASING IN THE WEST SATURDAY GIVEN THE
TROUPHPA AND WEAK ISENTROPIC LIFT. THEN WITH THE WARM AIR
ADVECTION/ISENTROPIC LIFT...KEPT IDEA OF SPREADING SOME OF THE SNOW
TO AREAS EAST OF THE DIVIDE SUNDAY. IF ITS ANY CONSOLATION...BOTH
THE GFS AND THE EURO AGREE ON THE FACT THAT A COL REGION WILL SHOW
UP OFF THE PAC NW COAST WHICH WOULD AT LEAST...IF NOTHING ELSE...ADD
CREDIBILITY TO THE LONG TERM SOLNS OF BOTH MODELS.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES A FAST-MOVING
UPPER LEVEL DISTURBANCE WILL PUSH SE ACROSS WYOMING EARLY MONDAY
MORNING SPREADING AREAS OF LIGHT SNOW AND FRQT MTN OBSCURATIONS
ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF MVFR -SN MAINLY VCNTY
AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH 15Z.  DRIER AIR WILL PUSH
NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.  GUSTY NW SFC WINDS WILL
CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY KDUB-KRIW AND EAST OF
THE BIGHORN RANGE.  THERE WILL BE SOME DECREASE IN THE WIND 21Z
MON-03Z TUE AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS
ALONG THE EAST SLOPES OF THE DIVIDE WITH MOUNTAIN WAVE ACTIVITY
LIKELY ALONG WITH AREAS OF LLWS VCNTY KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL DIVE SE ALONG THE DIVIDE
EARLY MONDAY MORNING WITH WIDESPREAD MVFR...AREAS OF IFR -SN BLSN
EXPECTED TO CONTINUE THROUGH 10Z...PUSHING INTO SW WY...VCNTY
KPNA-KBPI-KRKS 9Z-15Z.  DRIER AIR WILL PUSH INTO NW WYOMING AFTER
10Z BEHIND THIS SYSTEM...WITH MOST OF THE MVFR/IFR -SN EXITING SW WY
BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH MONDAY
AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND INTERSTATE
80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL
VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH WIDESPREAD
MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH MTNS MOSTLY
OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.  RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN THE
AFTERNOON EAST OF THE CONTINENTAL DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...HIGH WIND WATCH FROM MONDAY
EVENING THROUGH TUESDAY MORNING WYZ002-003.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...AEM
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 240635
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1131 PM MST SUN NOV 23 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH MONDAY (ISSUED AT 308 PM MST)

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE LOW SPINNING OVER SOUTHWEST ALASKA WILL EJECT ANOTHER SHORTWAVE
TROUGH THAT WILL EVENTUALLY TRACK SOUTHEAST IN THE FORM OF AN
ALBERTA CLIPPER ACROSS THE NORTHERN PLAINS BY TUE.. AS A
RESULT...THE ON GOING LIGHT SNOWFALL OVER THE FAR WEST BEING FED BY
A MOIST PACIFIC NORTHWEST FLOW WILL BECOME ENHANCED AS THIS WEATHER
FEATURE DRAWS CLOSER. SNOWFALL WILL CONTINUE TO INCREASE IN THE WEST
TUESDAY AND CONTINUE TUESDAY NIGHT. SNOWFALL WILL SPREAD INTO
NORTHERN WY EAST OF THE DIVIDE TUESDAY AS ISENTROPIC LIFT...Q VECTOR
FORCING AND THE NORTHEAST PROGRESSION OF THE JET ACROSS THE CWA
ENHANCES THE PULL OF PACIFIC MOISTURE FROM THE NORTHWEST. THE
SNOWFALL WILL CONTINUE IN NORTHERN WY THROUGH TUESDAY NIGHT.
SNOWFALL WILL END WEDNESDAY AS THE SYSTEM PULLS TO THE SOUTHEAST.
SNOWFALL AMOUNTS WITH THIS SYSTEM WILL LIKELY AMOUNT TO 3 TO 6
INCHES IN THE WESTERN MTNS...1 TO 3 INCHES IN THE WESTERN VALLEYS
AND 3 TO 9 INCHES IN THE BIG HORN MTNS. MOST OF THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL HAVE LITTLE IF ANY ACCUMULATION.

THE OTHER CONCERN WITH THIS PARTICULAR WEATHER FEATURE IS WIND. H7
WIND WIND SPEEDS ARE PROJECTED TO INCREASE TO AT LEAST 55 KNOTS LATE
TUESDAY NIGHT AND INTO WEDNESDAY MORNING OVER NORTHERN...CENTRAL AND
EASTERN WY. IN ADDITION...MTN WAVE POTENTIAL CANNOT BE RULED OUT
WITH A FROUDE NUMBER OF 1 NEAR CLARK ALONG WITH A BACKING WIND WITH
TIME. HOWEVER...FAVORABLE MTN TOP INVERSIONS APPEAR TO BE LACKING.
ANOTHER FAVORABLE MARKER ARE 6 DECAMETER HEIGHT LINES SPACED APART
EVERY 3 DECAMETERS OVER WY TUESDAY NIGHT. HAVE INDICATED BORDERLINE
HIGH WIND CRITERIA IN THE GRIDS FOR NOW FROM 03Z WED THROUGH 21Z WED
WITH THE STRONG WIND POTENTIAL FOR THE CODY FOOTHILLS TUE NT/WED AND
FRO THE SOUTHERN WIND CORRIDOR MAINLY ON WED. THE EAST SLOPE OF THE
WIND RIVER...ABSAROKA AND BIG HORN MTNS WILL EXPERIENCE CONSIDERABLE
BLOWING SNOW DURING THIS EVENT.

FOR THANKSGIVING DAY...THE EURO AND THE GFS APPEAR...AT LEAST FOR
NOW...TO BE MORE IN AGREEMENT THEN PAST RUNS WITH THE IDEA OF A
FLATTENING RIDGE FOR THURSDAY WITH THE NEXT SHORTWAVE WAVE THAT HAS
BEEN IN QUESTION FINALLY COMING INTO PLAY FRIDAY. HAVE KEPT HIGHER CHANCES
OF SNOW IN THE NORTHERN MTNS FOR THU TO TAKE INTO ACCOUNT THE
UNCERTAINTY OF WHAT THE NORTHERN STREAM ENERGY MAY HAVE IN STORE FOR
US. THEN INCREASED POPS IN NW WY FOR SNOW FRIDAY WITH THAT DELAYED
SHORTWAVE WAVE. HAVE SNOW INCREASING IN THE WEST SATURDAY GIVEN THE
TROUPHPA AND WEAK ISENTROPIC LIFT. THEN WITH THE WARM AIR
ADVECTION/ISENTROPIC LIFT...KEPT IDEA OF SPREADING SOME OF THE SNOW
TO AREAS EAST OF THE DIVIDE SUNDAY. IF ITS ANY CONSOLATION...BOTH
THE GFS AND THE EURO AGREE ON THE FACT THAT A COL REGION WILL SHOW
UP OFF THE PAC NW COAST WHICH WOULD AT LEAST...IF NOTHING ELSE...ADD
CREDIBILITY TO THE LONG TERM SOLNS OF BOTH MODELS.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES A FAST-MOVING
UPPER LEVEL DISTURBANCE WILL PUSH SE ACROSS WYOMING EARLY MONDAY
MORNING SPREADING AREAS OF LIGHT SNOW AND FRQT MTN OBSCURATIONS
ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF MVFR -SN MAINLY VCNTY
AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH 15Z.  DRIER AIR WILL PUSH
NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.  GUSTY NW SFC WINDS WILL
CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY KDUB-KRIW AND EAST OF
THE BIGHORN RANGE.  THERE WILL BE SOME DECREASE IN THE WIND 21Z
MON-03Z TUE AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS
ALONG THE EAST SLOPES OF THE DIVIDE WITH MOUNTAIN WAVE ACTIVITY
LIKELY ALONG WITH AREAS OF LLWS VCNTY KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL DIVE SE ALONG THE DIVIDE
EARLY MONDAY MORNING WITH WIDESPREAD MVFR...AREAS OF IFR -SN BLSN
EXPECTED TO CONTINUE THROUGH 10Z...PUSHING INTO SW WY...VCNTY
KPNA-KBPI-KRKS 9Z-15Z.  DRIER AIR WILL PUSH INTO NW WYOMING AFTER
10Z BEHIND THIS SYSTEM...WITH MOST OF THE MVFR/IFR -SN EXITING SW WY
BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH MONDAY
AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND INTERSTATE
80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL
VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH WIDESPREAD
MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH MTNS MOSTLY
OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.  RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN THE
AFTERNOON EAST OF THE CONTINENTAL DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...HIGH WIND WATCH FROM MONDAY
EVENING THROUGH TUESDAY MORNING WYZ002-003.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...AEM
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 240635
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1131 PM MST SUN NOV 23 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH MONDAY (ISSUED AT 308 PM MST)

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY

THE LOW SPINNING OVER SOUTHWEST ALASKA WILL EJECT ANOTHER SHORTWAVE
TROUGH THAT WILL EVENTUALLY TRACK SOUTHEAST IN THE FORM OF AN
ALBERTA CLIPPER ACROSS THE NORTHERN PLAINS BY TUE.. AS A
RESULT...THE ON GOING LIGHT SNOWFALL OVER THE FAR WEST BEING FED BY
A MOIST PACIFIC NORTHWEST FLOW WILL BECOME ENHANCED AS THIS WEATHER
FEATURE DRAWS CLOSER. SNOWFALL WILL CONTINUE TO INCREASE IN THE WEST
TUESDAY AND CONTINUE TUESDAY NIGHT. SNOWFALL WILL SPREAD INTO
NORTHERN WY EAST OF THE DIVIDE TUESDAY AS ISENTROPIC LIFT...Q VECTOR
FORCING AND THE NORTHEAST PROGRESSION OF THE JET ACROSS THE CWA
ENHANCES THE PULL OF PACIFIC MOISTURE FROM THE NORTHWEST. THE
SNOWFALL WILL CONTINUE IN NORTHERN WY THROUGH TUESDAY NIGHT.
SNOWFALL WILL END WEDNESDAY AS THE SYSTEM PULLS TO THE SOUTHEAST.
SNOWFALL AMOUNTS WITH THIS SYSTEM WILL LIKELY AMOUNT TO 3 TO 6
INCHES IN THE WESTERN MTNS...1 TO 3 INCHES IN THE WESTERN VALLEYS
AND 3 TO 9 INCHES IN THE BIG HORN MTNS. MOST OF THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL HAVE LITTLE IF ANY ACCUMULATION.

THE OTHER CONCERN WITH THIS PARTICULAR WEATHER FEATURE IS WIND. H7
WIND WIND SPEEDS ARE PROJECTED TO INCREASE TO AT LEAST 55 KNOTS LATE
TUESDAY NIGHT AND INTO WEDNESDAY MORNING OVER NORTHERN...CENTRAL AND
EASTERN WY. IN ADDITION...MTN WAVE POTENTIAL CANNOT BE RULED OUT
WITH A FROUDE NUMBER OF 1 NEAR CLARK ALONG WITH A BACKING WIND WITH
TIME. HOWEVER...FAVORABLE MTN TOP INVERSIONS APPEAR TO BE LACKING.
ANOTHER FAVORABLE MARKER ARE 6 DECAMETER HEIGHT LINES SPACED APART
EVERY 3 DECAMETERS OVER WY TUESDAY NIGHT. HAVE INDICATED BORDERLINE
HIGH WIND CRITERIA IN THE GRIDS FOR NOW FROM 03Z WED THROUGH 21Z WED
WITH THE STRONG WIND POTENTIAL FOR THE CODY FOOTHILLS TUE NT/WED AND
FRO THE SOUTHERN WIND CORRIDOR MAINLY ON WED. THE EAST SLOPE OF THE
WIND RIVER...ABSAROKA AND BIG HORN MTNS WILL EXPERIENCE CONSIDERABLE
BLOWING SNOW DURING THIS EVENT.

FOR THANKSGIVING DAY...THE EURO AND THE GFS APPEAR...AT LEAST FOR
NOW...TO BE MORE IN AGREEMENT THEN PAST RUNS WITH THE IDEA OF A
FLATTENING RIDGE FOR THURSDAY WITH THE NEXT SHORTWAVE WAVE THAT HAS
BEEN IN QUESTION FINALLY COMING INTO PLAY FRIDAY. HAVE KEPT HIGHER CHANCES
OF SNOW IN THE NORTHERN MTNS FOR THU TO TAKE INTO ACCOUNT THE
UNCERTAINTY OF WHAT THE NORTHERN STREAM ENERGY MAY HAVE IN STORE FOR
US. THEN INCREASED POPS IN NW WY FOR SNOW FRIDAY WITH THAT DELAYED
SHORTWAVE WAVE. HAVE SNOW INCREASING IN THE WEST SATURDAY GIVEN THE
TROUPHPA AND WEAK ISENTROPIC LIFT. THEN WITH THE WARM AIR
ADVECTION/ISENTROPIC LIFT...KEPT IDEA OF SPREADING SOME OF THE SNOW
TO AREAS EAST OF THE DIVIDE SUNDAY. IF ITS ANY CONSOLATION...BOTH
THE GFS AND THE EURO AGREE ON THE FACT THAT A COL REGION WILL SHOW
UP OFF THE PAC NW COAST WHICH WOULD AT LEAST...IF NOTHING ELSE...ADD
CREDIBILITY TO THE LONG TERM SOLNS OF BOTH MODELS.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES A FAST-MOVING
UPPER LEVEL DISTURBANCE WILL PUSH SE ACROSS WYOMING EARLY MONDAY
MORNING SPREADING AREAS OF LIGHT SNOW AND FRQT MTN OBSCURATIONS
ACROSS THE BIGHORN RANGE WITH LOCAL AREAS OF MVFR -SN MAINLY VCNTY
AND EAST OF A KCOD-KWRL-KCPR LINE THROUGH 15Z.  DRIER AIR WILL PUSH
NW-SE BEHIND THIS SYSTEM 15Z-18Z MONDAY.  GUSTY NW SFC WINDS WILL
CONTINUE THROUGH MID-AFTN...ESPECIALLY VCNTY KDUB-KRIW AND EAST OF
THE BIGHORN RANGE.  THERE WILL BE SOME DECREASE IN THE WIND 21Z
MON-03Z TUE AND THEN RIDGE TOP WEST WINDS WILL INCREASE TO 40-50KTS
ALONG THE EAST SLOPES OF THE DIVIDE WITH MOUNTAIN WAVE ACTIVITY
LIKELY ALONG WITH AREAS OF LLWS VCNTY KCOD-KDUB 3Z-12Z TUESDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A FAST-MOVING UPPER LEVEL DISTURBANCE WILL DIVE SE ALONG THE DIVIDE
EARLY MONDAY MORNING WITH WIDESPREAD MVFR...AREAS OF IFR -SN BLSN
EXPECTED TO CONTINUE THROUGH 10Z...PUSHING INTO SW WY...VCNTY
KPNA-KBPI-KRKS 9Z-15Z.  DRIER AIR WILL PUSH INTO NW WYOMING AFTER
10Z BEHIND THIS SYSTEM...WITH MOST OF THE MVFR/IFR -SN EXITING SW WY
BY 15Z.  GUSTY NW SFC WINDS WILL FOLLOW THE SYSTEM THROUGH MONDAY
AFTN...ESPECIALLY ACROSS THE UPPER GREEN RIVER BASIN AND INTERSTATE
80 CORRIDOR.  A MOIST WESTERLY FLOW WILL BRING INCREASING SNOWFALL
VCNTY AND NORTH OF A KPNA-KEMM LINE 08Z-12Z TUESDAY WITH WIDESPREAD
MVFR -SN...AREAS OF IFR -SN EXPECTED BY 12Z ALONG WITH MTNS MOSTLY
OBSCD.

&&

.FIRE WEATHER...

NORTHWEST FLOW ALOFT WILL REMAIN OVER WESTERN AND CENTRAL WYOMING.
A FAST MOVING PACIFIC LOW PRESSURE TROUGH IN THE FLOW WILL SWEEP
THROUGH THE AREA TONIGHT AND MONDAY MORNING. THE NORTHERN AND
WESTERN MOUNTAINS WILL SEE SOME LIGHT SNOWFALL. SOME OF THE SNOW
WILL MAKE IT TO THE VALLEYS OF THE WEST. EAST OF THE DIVIDE LITTLE
IF ANY SNOWFALL IS EXPECTED BUT BRISK NORTHWEST WINDS WILL CONTINUE.
THE LOWER AIR MASS WILL BE WELL MIXED KEEPING OVERNIGHT LOWS UP
WITH SLIGHT COOLING ON MONDAY BEHIND THE TROUGH. THE SNOWFALL IN
THE WEST AND NORTH SHOULD TAPER OFF FROM LATE MORNING THROUGH
EARLY AFTERNOON.  RELATIVE HUMIDITY WILL BE ELEVATED WITH GENERALLY
LOW MIXING HEIGHTS. WINDIER AREAS MAY SEE FAIR SMOKE DISPERSAL IN THE
AFTERNOON EAST OF THE CONTINENTAL DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...HIGH WIND WATCH FROM MONDAY
EVENING THROUGH TUESDAY MORNING WYZ002-003.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...LIPSON
AVIATION...AEM
FIRE WEATHER...C.BAKER












    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities