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000
FXUS65 KCYS 061142 AAA
AFDCYS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CHEYENNE WY
542 AM MDT FRI MAY 6 2016

.UPDATE...FOR THE EARLY MORNING AVIATION FORECAST PACKAGE UPDATE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM MDT FRI MAY 6 2016

AN EXTREMELY ACTIVE PERIOD OF WEATHER OVER THE NEXT FEW DAYS WITH AT
LEAST SOME POTENTIAL FOR SEVERE THUNDERSTORMS...FLASH FLOODING...AND
ACCUMULATING MOUNTAIN SNOW. MORNING WATER VAPOR AND OBJECTIVE UPPER-
AIR ANALYSIS REVEAL AN IMPRESSIVE OMEGA BLOCK ENCOMPASSING VIRTUALLY
ALL OF THE LOWER 48. HIGH-AMPLITUDE RIDGING OVER THE GREAT PLAINS IS
EXPECTED TO BREAK DOWN OVER THE NEXT 12 HOURS...BUT EXPECT VERY SLOW
PROGRESSION OF THE SOUTHWESTERN US LOW GIVEN THE CURRENT LARGE SCALE
BLOCKING PATTERN IN PLACE.

SOUTHWEST FLOW ALOFT IS ALREADY INCREASING OVER THE CWA THIS AM WITH
DEEP MOISTURE STREAMING NORTHWARD. WE WILL NOT SEE AS MUCH SUN AS WE
HAVE OVER THE LAST FEW DAYS...BUT EXPECT ANOTHER MILD AFTERNOON WITH
MODELS STILL SHOWING H7 TEMPS BETWEEN +8 AND +10 DEG C. IT WILL ALSO
BE A WARM START TO THE DAY WITH CHEYENNE SITTING AT 53 DEGREES AS OF
3 AM MDT. WEAK SURFACE CYCLOGENESIS WILL OCCUR OVER NORTHEASTERN
CO TODAY...RESULTING IN LOW-LEVEL UPSLOPE ALONG AND EAST OF THE
LARAMIE RANGE HEADING INTO THIS AFTERNOON. LOW-LEVEL MOISTURE IS
EXPECTED TO INCREASE WITH DEW POINTS IN THE 40S TO NEAR 50. WARM
TEMPERATURES AT THE SURFACE WILL PROMOTE STEEP LAPSE
RATES...POSSIBLY YIELDING CAPES AROUND 500-1000 J/KG AREAWIDE.
FORECAST SOUNDINGS LOOK FAVORABLE FOR STRONG TO LOCALLY SEVERE
CONVECTION...SO ADDED MENTION OF SMALL HAIL AND GUSTY WINDS FOR
ALL ZONES THIS AFTERNOON. THE 06Z DY1 CONVECTIVE OUTLOOK FROM SPC
HAS MUCH OF THE AREA IN A MARGINAL RISK. A PIECE OF MID-LEVEL VORT
ENERGY IS PROGGED TO ROTATE ACROSS SOUTHEAST WYO LATE
TONIGHT...BETWEEN 00Z AND 12Z SAT. BELIEVE THIS WILL INTERACT WITH
A PRONOUNCED FRONTAL BOUNDARY AND DEEP UPSLOPE FLOW TO PRODUCE AN
AREA OF MODERATE TO HEAVY PRECIPITATION OVER OUR NORTHERN
ZONES...SO WENT AHEAD AND INTRODUCED CATEGORICAL POPS PER
COORDINATION WITH UNR.

BIG CHALLENGES WITH THE FORECAST FOR SATURDAY. MODELS SHOW THE UPPER
LOW CENTERED OVER THE FOUR CORNERS WITH ONE OR MORE SIGNIFICANT VORT
LOBES AFFECTING THE CWA...THE STRONGER OF WHICH APPEARS TO ARRIVE IN
THE LATE AFTERNOON/EVENING. STRONG DYNAMIC SUPPORT IS LIKELY THROUGH
THE DAY WITH CYCLOGENESIS OVER NORTHEAST CO REINFORCING UPSLOPE FLOW
AND UPPER-LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100-110 KNOT
H25 JET OVER SOUTHEAST CO. SEVERE THUNDERSTORMS ARE STARTING TO LOOK
LIKE MORE OF A THREAT...MAINLY IN THE CYS-TOR-SNY TRIANGLE AND AREAS
TO THE SOUTH AND EAST. WOULD LIKE TO SEE THE POSITION OF THE SURFACE
LOW FARTHER NORTHWEST FOR A BIG OUTBREAK...BUT NONETHELESS THIS DOES
SUPPORT MOIST EASTERLY SFC FLOW VEERING TO THE SOUTHEAST AT H7 WHICH
YIELDS SHEAR PROFILES FAVORABLE FOR SUPERCELLS. BOTH THE GFS AND NAM
SHOW 1500-2500 J/KG OF SBCAPE AND EXCELLENT 0-1 KM EHI GIVEN LOW-LVL
SHEAR IN PLACE. SLIGHT RISK FROM SPC NOW INCLUDES I80 BETWEEN SIDNEY
AND CHEYENNE...SO DECIDED TO ADD MENTION OF SEVERE. CIPS ANALOGS ARE
CONSISTENT WITH SEVERAL NORTHEAST COLORADO TORNADO EVENTS...SO WOULD
NOT BE SURPRISED TO SEE AN ISOLATED TORNADO OR TWO NEAR THE COLORADO
BORDER ON SATURDAY.

IN ADDITION TO THE RISK FOR SEVERE THUNDERSTORMS...A MORE WIDESPREAD
THREAT FOR VERY HEAVY RAIN IS EXPECTED. DEEP MOISTURE AND IMPRESSIVE
LARGE SCALE DYNAMICS WILL BE IN PLACE THROUGH THE NIGHT AS THE UPPER
LOW WILL BE SLOW MOVING DUE TO A REX BLOCK. ABSOLUTELY NO DOUBT THAT
THUNDERSTORMS ON SATURDAY/SATURDAY NIGHT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH PWATS OF 0.5 TO 1.0 INCH BEING WELL ABOVE CLIMO. SOME
CONCERN FOR TRAINING CONVECTION AS WELL. THE PRIMARY ISSUE HERE WILL
LIKELY BE OVER THE HIGHER TERRAIN WITH AN ENHANCED LIKELIHOOD FOR AN
ACCELERATED SNOWMELT AND FLASH FLOODING OF CREEKS/STREAMS. GAVE SOME
CONSIDERATION TO A FLASH FLOOD WATCH...BUT WE DECIDED TO LET THE DAY
SHIFT TAKE ANOTHER LOOK AND SEE IF THEY CAN NARROW DOWN THE SPECIFIC
THREAT AREAS. WPC HAS MUCH OF OUR CWA IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL ON SATURDAY...SO FULLY EXPECT THAT FLOOD AND/OR FLASH FLOOD
WATCHES WILL BE NECESSARY SOON. BY LATE SATURDAY NIGHT...WBZ HEIGHTS
FINALLY DROP BELOW 10K FEET WHICH WOULD SUGGEST MOUNTAIN SNOW. COULD
SEE ADVISORY-LEVEL AMOUNTS IF THE CHANGEOVER OCCURS SOON ENOUGH OVER
THE SNOWY AND SIERRA MADRE RANGES.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 401 AM MDT FRI MAY 6 2016

WET PATTERN CONTINUES INTO SUNDAY AS THE UPPER LOW ESSENTIALLY
STALLS ACROSS SOUTHEAST WYOMING WITH HIGH CHANCE TO LIKELY POPS A
FAIRLY GOOD BET ACROSS THE ENTIRE FORECAST AREA. CONCERNS FOR
FLOOD POTENTIAL WILL CONTINUE INTO SUNDAY GIVEN COVERAGE OF RAIN
BUT COOLER TEMPERATURES SHOULD MEAN MORE SNOW IN THE HIGHER
ELEVATIONS VERSUS RAIN BY LATE IN THE WEEKEND. THE AIRMASS WILL
BE A BIT MORE STABILIZED ON SUNDAY DUE TO COOLER BOUNDARY
LAYER CONDITIONS...HOWEVER WE STILL EXPECT TO SEE THE POTENTIAL
FOR ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENING
HOURS. THE UPPER LOW FINALLY KICKS OUT TO THE NORTHEAST LATE
MONDAY WITH A DOWNWARD TREND IN POPS EXPECTED ACROSS THE SOUTHERN
ZONES TUESDAY WITH CHANCE POPS FOR SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE NORTHERN ZONES AHEAD OF THE NEXT
APPROACHING UPPER TROUGH MOVING DOWN FROM MONTANA. THAT TROUGH
MOVES EAST BY THURSDAY WITH SLIGHT CHANCE POPS EXPECTED GOING INTO
LATE WEEK. OVERALL NEXT WEEK LOOKS TO BE COOLER THAN WHAT WE HAVE
SEEN THE LATTER PART OF THIS WEEK WITH DAILY HIGH TEMPS GENERALLY
IN THE 40S-50S WEST AND 60S EAST. ELEVATIONS ABOVE 9500 FT LOOK
TO SEE HIGHS IN THE MID 30S TO AROUND 40 THROUGH THE WEEK...COOL
ENOUGH TO SLOW THE SNOWMELT PROCESS A BIT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 542 AM MDT FRI MAY 6 2016

FOLLOWED TREND AS DEPICTED BY HRRR THIS PACKAGE IN BRINGING
SHOWERS AND ISOLATED THUNDERSTORMS UP INTO SE WYOMING MID TO LATE
AFTERNOON THEN INTO THE NEBRASKA PANHANDLE BY EARLY EVENING.
CEILINGS AND VISIBILITIES PREVAILING VFR THROUGH LATE AFTERNOON
INTO THE EVENING HOURS WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS PASSING ACROSS THE REGION. LOWERED CEILINGS FOR
SCOTTSBLUFF, CHEYENNE, LARAMIE AND RAWLINS DOWN TO MVFR AFTER 06Z
WHERE GREATER COVERAGE OF SHOWERS WILL BE AS DEEPER MOISTURE MOVES
UP FROM THE SOUTH.

&&

.FIRE WEATHER...
ISSUED AT 401 AM MDT FRI MAY 6 2016

COOLER AND WETTER PATTERN STILL PROJECTED TO SET UP ACROSS SE
WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH THE WEEKEND.
PATTERN BECOMES A BIT LESS ACTIVE FOR SHOWERS AND THUNDERSTORMS
BY MID WEEK WITH PROJECTED CONDITIONS EXPECTED TO REMAIN WELL
ABOVE ANY CRITICAL THRESHOLDS FOR FIRE WEATHER CONCERNS IN THE
FORSEEABLE FUTURE.

&&

.HYDROLOGY...
ISSUED AT 401 AM MDT FRI MAY 6 2016

WARM TEMPERATURES WILL CONTINUE TODAY WITH AFTERNOON HIGHS LIKELY IN
THE 50S IN THE HIGH ELEVATIONS OF THE SNOWY/SIERRA MADRE RANGES. MTN
CREEKS AND STREAMS WILL CONTINUE TO SEE NOTABLE RISES IN THE NEXT 24
TO 48 HOURS. WIDESPREAD THUNDERSTORMS COULD PRODUCE HEAVY RAIN TODAY
AND SATURDAY. RAIN ON SNOW COULD YIELD ACCELERATED SNOWMELT AND LEAD
TO FLASH FLOODING...ESPECIALLY OF MOUNTAIN CREEKS/STREAMS. THERE MAY
ALSO BE A THREAT FOR LOCALIZED FLASH FLOODING OVER THE PLAINS. FLASH
FLOOD WATCHES MAY BECOME NECESSARY SOON.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...CLH
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...JG
HYDROLOGY...CLH




000
FXUS65 KCYS 061142 AAA
AFDCYS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CHEYENNE WY
542 AM MDT FRI MAY 6 2016

.UPDATE...FOR THE EARLY MORNING AVIATION FORECAST PACKAGE UPDATE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM MDT FRI MAY 6 2016

AN EXTREMELY ACTIVE PERIOD OF WEATHER OVER THE NEXT FEW DAYS WITH AT
LEAST SOME POTENTIAL FOR SEVERE THUNDERSTORMS...FLASH FLOODING...AND
ACCUMULATING MOUNTAIN SNOW. MORNING WATER VAPOR AND OBJECTIVE UPPER-
AIR ANALYSIS REVEAL AN IMPRESSIVE OMEGA BLOCK ENCOMPASSING VIRTUALLY
ALL OF THE LOWER 48. HIGH-AMPLITUDE RIDGING OVER THE GREAT PLAINS IS
EXPECTED TO BREAK DOWN OVER THE NEXT 12 HOURS...BUT EXPECT VERY SLOW
PROGRESSION OF THE SOUTHWESTERN US LOW GIVEN THE CURRENT LARGE SCALE
BLOCKING PATTERN IN PLACE.

SOUTHWEST FLOW ALOFT IS ALREADY INCREASING OVER THE CWA THIS AM WITH
DEEP MOISTURE STREAMING NORTHWARD. WE WILL NOT SEE AS MUCH SUN AS WE
HAVE OVER THE LAST FEW DAYS...BUT EXPECT ANOTHER MILD AFTERNOON WITH
MODELS STILL SHOWING H7 TEMPS BETWEEN +8 AND +10 DEG C. IT WILL ALSO
BE A WARM START TO THE DAY WITH CHEYENNE SITTING AT 53 DEGREES AS OF
3 AM MDT. WEAK SURFACE CYCLOGENESIS WILL OCCUR OVER NORTHEASTERN
CO TODAY...RESULTING IN LOW-LEVEL UPSLOPE ALONG AND EAST OF THE
LARAMIE RANGE HEADING INTO THIS AFTERNOON. LOW-LEVEL MOISTURE IS
EXPECTED TO INCREASE WITH DEW POINTS IN THE 40S TO NEAR 50. WARM
TEMPERATURES AT THE SURFACE WILL PROMOTE STEEP LAPSE
RATES...POSSIBLY YIELDING CAPES AROUND 500-1000 J/KG AREAWIDE.
FORECAST SOUNDINGS LOOK FAVORABLE FOR STRONG TO LOCALLY SEVERE
CONVECTION...SO ADDED MENTION OF SMALL HAIL AND GUSTY WINDS FOR
ALL ZONES THIS AFTERNOON. THE 06Z DY1 CONVECTIVE OUTLOOK FROM SPC
HAS MUCH OF THE AREA IN A MARGINAL RISK. A PIECE OF MID-LEVEL VORT
ENERGY IS PROGGED TO ROTATE ACROSS SOUTHEAST WYO LATE
TONIGHT...BETWEEN 00Z AND 12Z SAT. BELIEVE THIS WILL INTERACT WITH
A PRONOUNCED FRONTAL BOUNDARY AND DEEP UPSLOPE FLOW TO PRODUCE AN
AREA OF MODERATE TO HEAVY PRECIPITATION OVER OUR NORTHERN
ZONES...SO WENT AHEAD AND INTRODUCED CATEGORICAL POPS PER
COORDINATION WITH UNR.

BIG CHALLENGES WITH THE FORECAST FOR SATURDAY. MODELS SHOW THE UPPER
LOW CENTERED OVER THE FOUR CORNERS WITH ONE OR MORE SIGNIFICANT VORT
LOBES AFFECTING THE CWA...THE STRONGER OF WHICH APPEARS TO ARRIVE IN
THE LATE AFTERNOON/EVENING. STRONG DYNAMIC SUPPORT IS LIKELY THROUGH
THE DAY WITH CYCLOGENESIS OVER NORTHEAST CO REINFORCING UPSLOPE FLOW
AND UPPER-LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100-110 KNOT
H25 JET OVER SOUTHEAST CO. SEVERE THUNDERSTORMS ARE STARTING TO LOOK
LIKE MORE OF A THREAT...MAINLY IN THE CYS-TOR-SNY TRIANGLE AND AREAS
TO THE SOUTH AND EAST. WOULD LIKE TO SEE THE POSITION OF THE SURFACE
LOW FARTHER NORTHWEST FOR A BIG OUTBREAK...BUT NONETHELESS THIS DOES
SUPPORT MOIST EASTERLY SFC FLOW VEERING TO THE SOUTHEAST AT H7 WHICH
YIELDS SHEAR PROFILES FAVORABLE FOR SUPERCELLS. BOTH THE GFS AND NAM
SHOW 1500-2500 J/KG OF SBCAPE AND EXCELLENT 0-1 KM EHI GIVEN LOW-LVL
SHEAR IN PLACE. SLIGHT RISK FROM SPC NOW INCLUDES I80 BETWEEN SIDNEY
AND CHEYENNE...SO DECIDED TO ADD MENTION OF SEVERE. CIPS ANALOGS ARE
CONSISTENT WITH SEVERAL NORTHEAST COLORADO TORNADO EVENTS...SO WOULD
NOT BE SURPRISED TO SEE AN ISOLATED TORNADO OR TWO NEAR THE COLORADO
BORDER ON SATURDAY.

IN ADDITION TO THE RISK FOR SEVERE THUNDERSTORMS...A MORE WIDESPREAD
THREAT FOR VERY HEAVY RAIN IS EXPECTED. DEEP MOISTURE AND IMPRESSIVE
LARGE SCALE DYNAMICS WILL BE IN PLACE THROUGH THE NIGHT AS THE UPPER
LOW WILL BE SLOW MOVING DUE TO A REX BLOCK. ABSOLUTELY NO DOUBT THAT
THUNDERSTORMS ON SATURDAY/SATURDAY NIGHT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH PWATS OF 0.5 TO 1.0 INCH BEING WELL ABOVE CLIMO. SOME
CONCERN FOR TRAINING CONVECTION AS WELL. THE PRIMARY ISSUE HERE WILL
LIKELY BE OVER THE HIGHER TERRAIN WITH AN ENHANCED LIKELIHOOD FOR AN
ACCELERATED SNOWMELT AND FLASH FLOODING OF CREEKS/STREAMS. GAVE SOME
CONSIDERATION TO A FLASH FLOOD WATCH...BUT WE DECIDED TO LET THE DAY
SHIFT TAKE ANOTHER LOOK AND SEE IF THEY CAN NARROW DOWN THE SPECIFIC
THREAT AREAS. WPC HAS MUCH OF OUR CWA IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL ON SATURDAY...SO FULLY EXPECT THAT FLOOD AND/OR FLASH FLOOD
WATCHES WILL BE NECESSARY SOON. BY LATE SATURDAY NIGHT...WBZ HEIGHTS
FINALLY DROP BELOW 10K FEET WHICH WOULD SUGGEST MOUNTAIN SNOW. COULD
SEE ADVISORY-LEVEL AMOUNTS IF THE CHANGEOVER OCCURS SOON ENOUGH OVER
THE SNOWY AND SIERRA MADRE RANGES.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 401 AM MDT FRI MAY 6 2016

WET PATTERN CONTINUES INTO SUNDAY AS THE UPPER LOW ESSENTIALLY
STALLS ACROSS SOUTHEAST WYOMING WITH HIGH CHANCE TO LIKELY POPS A
FAIRLY GOOD BET ACROSS THE ENTIRE FORECAST AREA. CONCERNS FOR
FLOOD POTENTIAL WILL CONTINUE INTO SUNDAY GIVEN COVERAGE OF RAIN
BUT COOLER TEMPERATURES SHOULD MEAN MORE SNOW IN THE HIGHER
ELEVATIONS VERSUS RAIN BY LATE IN THE WEEKEND. THE AIRMASS WILL
BE A BIT MORE STABILIZED ON SUNDAY DUE TO COOLER BOUNDARY
LAYER CONDITIONS...HOWEVER WE STILL EXPECT TO SEE THE POTENTIAL
FOR ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENING
HOURS. THE UPPER LOW FINALLY KICKS OUT TO THE NORTHEAST LATE
MONDAY WITH A DOWNWARD TREND IN POPS EXPECTED ACROSS THE SOUTHERN
ZONES TUESDAY WITH CHANCE POPS FOR SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE NORTHERN ZONES AHEAD OF THE NEXT
APPROACHING UPPER TROUGH MOVING DOWN FROM MONTANA. THAT TROUGH
MOVES EAST BY THURSDAY WITH SLIGHT CHANCE POPS EXPECTED GOING INTO
LATE WEEK. OVERALL NEXT WEEK LOOKS TO BE COOLER THAN WHAT WE HAVE
SEEN THE LATTER PART OF THIS WEEK WITH DAILY HIGH TEMPS GENERALLY
IN THE 40S-50S WEST AND 60S EAST. ELEVATIONS ABOVE 9500 FT LOOK
TO SEE HIGHS IN THE MID 30S TO AROUND 40 THROUGH THE WEEK...COOL
ENOUGH TO SLOW THE SNOWMELT PROCESS A BIT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 542 AM MDT FRI MAY 6 2016

FOLLOWED TREND AS DEPICTED BY HRRR THIS PACKAGE IN BRINGING
SHOWERS AND ISOLATED THUNDERSTORMS UP INTO SE WYOMING MID TO LATE
AFTERNOON THEN INTO THE NEBRASKA PANHANDLE BY EARLY EVENING.
CEILINGS AND VISIBILITIES PREVAILING VFR THROUGH LATE AFTERNOON
INTO THE EVENING HOURS WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS PASSING ACROSS THE REGION. LOWERED CEILINGS FOR
SCOTTSBLUFF, CHEYENNE, LARAMIE AND RAWLINS DOWN TO MVFR AFTER 06Z
WHERE GREATER COVERAGE OF SHOWERS WILL BE AS DEEPER MOISTURE MOVES
UP FROM THE SOUTH.

&&

.FIRE WEATHER...
ISSUED AT 401 AM MDT FRI MAY 6 2016

COOLER AND WETTER PATTERN STILL PROJECTED TO SET UP ACROSS SE
WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH THE WEEKEND.
PATTERN BECOMES A BIT LESS ACTIVE FOR SHOWERS AND THUNDERSTORMS
BY MID WEEK WITH PROJECTED CONDITIONS EXPECTED TO REMAIN WELL
ABOVE ANY CRITICAL THRESHOLDS FOR FIRE WEATHER CONCERNS IN THE
FORSEEABLE FUTURE.

&&

.HYDROLOGY...
ISSUED AT 401 AM MDT FRI MAY 6 2016

WARM TEMPERATURES WILL CONTINUE TODAY WITH AFTERNOON HIGHS LIKELY IN
THE 50S IN THE HIGH ELEVATIONS OF THE SNOWY/SIERRA MADRE RANGES. MTN
CREEKS AND STREAMS WILL CONTINUE TO SEE NOTABLE RISES IN THE NEXT 24
TO 48 HOURS. WIDESPREAD THUNDERSTORMS COULD PRODUCE HEAVY RAIN TODAY
AND SATURDAY. RAIN ON SNOW COULD YIELD ACCELERATED SNOWMELT AND LEAD
TO FLASH FLOODING...ESPECIALLY OF MOUNTAIN CREEKS/STREAMS. THERE MAY
ALSO BE A THREAT FOR LOCALIZED FLASH FLOODING OVER THE PLAINS. FLASH
FLOOD WATCHES MAY BECOME NECESSARY SOON.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...CLH
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...JG
HYDROLOGY...CLH



  [top]

000
FXUS63 KUNR 061037
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
437 AM MDT FRI MAY 6 2016

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 229 AM MDT FRI MAY 6 2016

08Z SURFACE ANALYSIS HAD COLD FRONT FROM NORTHEAST ND INTO
SOUTHEAST MT TO NORTHWEST WY...PUSHING SLOWLY SOUTHEAST AS SURFACE
HIGH OVER SOUTHWEST CANADA NOSES INTO THE NORTHERN PLAINS/ROCKIES.
LOW LEVEL JET AHEAD OF COLD FRONT STRUGGLING TO PRODUCE ACCAS AT
THIS POINT...BUT MAY YET STILL DEVELOP BEFORE SUNRISE. WATER
VAPOUR SHOWED UPPER LOW OFF CA COAST...AND THIS WILL BE THE MAIN
WEATHER MAKER IN THE SHORT TERM.

TODAY/TONIGHT...UPPER LOW MOVES INTO THE FOUR CORNERS AREA BY 12Z
SATURDAY AS NOSE OF 120KT JET AT BASE OF UPPER LOW PUSHES INTO CO.
DIVERGENCE ON NOSE OF JET WILL PRODUCE SYNOPTIC LIFT OVER CO/WY
TODAY...SPREADING INTO CWA LATE THROUGH THIS EVENING. SURFACE
COLD FRONT SLIDES SOUTHEAST INTO NE THIS EVENING WITH
NORTHEASTERLY BOUNDARY LAYER FLOW BEHIND IT. UPSLOPE FLOW
COMBINES WITH UPSIDENCE UNDER DIVERGENCE TO PRODUCE HIGH POPS
ALONG FRONTAL BOUNDARY FROM WY INTO SOUTHWEST SD TONIGHT. FOR THIS
AFTERNOON...UP TO 1500J/KG MLCAPE WITH LITTLE MLCIN POOLS AHEAD OF
COLD FRONT. SHOULD SEE TSRA DEVELOP LATE THIS AFTERNOON OVER
WY/HIGHER TERRAIN AND PERSIST INTO THE EVENING HOURS AS IT SPREADS
EAST/NORTH. GIVEN MODEST INSTABILITY AND 0-6KM EFFECTIVE
SHEAR...SUSPECT AN ISOLATED SEVERE TSRA OR TWO MAY DEVELOP OVER
SOUTHWEST QUARTER OF CWA DURING/SHORTLY AFTER PEAK INSOLATION.
MARGINAL HAIL/SEVERE WIND GUSTS POSSIBLE. TEMPERATURES
TODAY/TONIGHT WILL BE NEAR GUIDANCE.

SATURDAY...UPPER LOW MOVES THROUGH CO INTO SOUTH CENTRAL WY.
AFOREMENTIONED FORCING WANES IN THE MORNING AS DRIER AIR CIRCULATES
INTO CWA FROM THE EASTERN DAKOTAS. BY AFTERNOON...SURFACE LOW
DEVELOPS OVER WESTERN NE IN RESPONSE TO ENERGY ROTATING AROUND
UPPER LOW. FLOW TURNS SOUTHEAST WITH MOISTURE RETURN. POPS
INCREASE LATER IN THE DAY AND INTO THE NIGHT ACROSS SOUTHERN
PORTIONS OF THE CWA AS WEAK INSTABILITY COMBINES WITH SYNOPTIC
SCALE LIFT. TEMPERATURES WILL BE NEAR GUIDANCE.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 229 AM MDT FRI MAY 6 2016

THE GREAT BASIN UPPER LOW WILL SLOWLY SLIDE TOWARD THE REGION
THROUGH THE FIRST HALF OF NEXT WEEK AS A TROUGH MOVES INTO THE NRN
ROCKIES. THIS SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
THROUGH TUESDAY TO WEDNESDAY. RIGHT NOW THE BEST CHANCES FOR
SHOWERS WILL BE SUNDAY THROUGH TUESDAY. THIS SYSTEM WILL ALSO
BRING NEAR TO SLIGHTLY BELOW AVERAGE TEMPS. SLIGHTLY DRIER WEATHER
IS EXPECTED PAST MIDWEEK...BUT UNCERTAINTY REMAINS WITH THIS TYPE
OF PATTERN.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 437 AM MDT FRI MAY 6 2016

THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
TONIGHT. THE BEST CHANCES WILL BE ACROSS NORTHEAST WYOMING...THE
BLACK HILLS AREA...AND SOUTHWEST SOUTH DAKOTA. MVFR CONDITIONS ARE
POSSIBLE NEAR ANY PRECIP. OTHERWISE VFR CONDITIONS ARE EXPECTED.
WINDS WILL BECOME BREEZY FROM THE NORTH TO NORTHEAST TODAY.

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13




000
FXUS65 KCYS 061001
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
401 AM MDT FRI MAY 6 2016

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM MDT FRI MAY 6 2016

AN EXTREMELY ACTIVE PERIOD OF WEATHER OVER THE NEXT FEW DAYS WITH AT
LEAST SOME POTENTIAL FOR SEVERE THUNDERSTORMS...FLASH FLOODING...AND
ACCUMULATING MOUNTAIN SNOW. MORNING WATER VAPOR AND OBJECTIVE UPPER-
AIR ANALYSIS REVEAL AN IMPRESSIVE OMEGA BLOCK ENCOMPASSING VIRTUALLY
ALL OF THE LOWER 48. HIGH-AMPLITUDE RIDGING OVER THE GREAT PLAINS IS
EXPECTED TO BREAK DOWN OVER THE NEXT 12 HOURS...BUT EXPECT VERY SLOW
PROGRESSION OF THE SOUTHWESTERN US LOW GIVEN THE CURRENT LARGE SCALE
BLOCKING PATTERN IN PLACE.

SOUTHWEST FLOW ALOFT IS ALREADY INCREASING OVER THE CWA THIS AM WITH
DEEP MOISTURE STREAMING NORTHWARD. WE WILL NOT SEE AS MUCH SUN AS WE
HAVE OVER THE LAST FEW DAYS...BUT EXPECT ANOTHER MILD AFTERNOON WITH
MODELS STILL SHOWING H7 TEMPS BETWEEN +8 AND +10 DEG C. IT WILL ALSO
BE A WARM START TO THE DAY WITH CHEYENNE SITTING AT 53 DEGREES AS OF
3 AM MDT. WEAK SURFACE CYCLOGENESIS WILL OCCUR OVER NORTHEASTERN
CO TODAY...RESULTING IN LOW-LEVEL UPSLOPE ALONG AND EAST OF THE
LARAMIE RANGE HEADING INTO THIS AFTERNOON. LOW-LEVEL MOISTURE IS
EXPECTED TO INCREASE WITH DEW POINTS IN THE 40S TO NEAR 50. WARM
TEMPERATURES AT THE SURFACE WILL PROMOTE STEEP LAPSE
RATES...POSSIBLY YIELDING CAPES AROUND 500-1000 J/KG AREAWIDE.
FORECAST SOUNDINGS LOOK FAVORABLE FOR STRONG TO LOCALLY SEVERE
CONVECTION...SO ADDED MENTION OF SMALL HAIL AND GUSTY WINDS FOR
ALL ZONES THIS AFTERNOON. THE 06Z DY1 CONVECTIVE OUTLOOK FROM SPC
HAS MUCH OF THE AREA IN A MARGINAL RISK. A PIECE OF MID-LEVEL VORT
ENERGY IS PROGGED TO ROTATE ACROSS SOUTHEAST WYO LATE
TONIGHT...BETWEEN 00Z AND 12Z SAT. BELIEVE THIS WILL INTERACT WITH
A PRONOUNCED FRONTAL BOUNDARY AND DEEP UPSLOPE FLOW TO PRODUCE AN
AREA OF MODERATE TO HEAVY PRECIPITATION OVER OUR NORTHERN
ZONES...SO WENT AHEAD AND INTRODUCED CATEGORICAL POPS PER
COORDINATION WITH UNR.

BIG CHALLENGES WITH THE FORECAST FOR SATURDAY. MODELS SHOW THE UPPER
LOW CENTERED OVER THE FOUR CORNERS WITH ONE OR MORE SIGNIFICANT VORT
LOBES AFFECTING THE CWA...THE STRONGER OF WHICH APPEARS TO ARRIVE IN
THE LATE AFTERNOON/EVENING. STRONG DYNAMIC SUPPORT IS LIKELY THROUGH
THE DAY WITH CYCLOGENESIS OVER NORTHEAST CO REINFORCING UPSLOPE FLOW
AND UPPER-LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100-110 KNOT
H25 JET OVER SOUTHEAST CO. SEVERE THUNDERSTORMS ARE STARTING TO LOOK
LIKE MORE OF A THREAT...MAINLY IN THE CYS-TOR-SNY TRIANGLE AND AREAS
TO THE SOUTH AND EAST. WOULD LIKE TO SEE THE POSITION OF THE SURFACE
LOW FARTHER NORTHWEST FOR A BIG OUTBREAK...BUT NONETHELESS THIS DOES
SUPPORT MOIST EASTERLY SFC FLOW VEERING TO THE SOUTHEAST AT H7 WHICH
YIELDS SHEAR PROFILES FAVORABLE FOR SUPERCELLS. BOTH THE GFS AND NAM
SHOW 1500-2500 J/KG OF SBCAPE AND EXCELLENT 0-1 KM EHI GIVEN LOW-LVL
SHEAR IN PLACE. SLIGHT RISK FROM SPC NOW INCLUDES I80 BETWEEN SIDNEY
AND CHEYENNE...SO DECIDED TO ADD MENTION OF SEVERE. CIPS ANALOGS ARE
CONSISTENT WITH SEVERAL NORTHEAST COLORADO TORNADO EVENTS...SO WOULD
NOT BE SURPRISED TO SEE AN ISOLATED TORNADO OR TWO NEAR THE COLORADO
BORDER ON SATURDAY.

IN ADDITION TO THE RISK FOR SEVERE THUNDERSTORMS...A MORE WIDESPREAD
THREAT FOR VERY HEAVY RAIN IS EXPECTED. DEEP MOISTURE AND IMPRESSIVE
LARGE SCALE DYNAMICS WILL BE IN PLACE THROUGH THE NIGHT AS THE UPPER
LOW WILL BE SLOW MOVING DUE TO A REX BLOCK. ABSOLUTELY NO DOUBT THAT
THUNDERSTORMS ON SATURDAY/SATURDAY NIGHT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH PWATS OF 0.5 TO 1.0 INCH BEING WELL ABOVE CLIMO. SOME
CONCERN FOR TRAINING CONVECTION AS WELL. THE PRIMARY ISSUE HERE WILL
LIKELY BE OVER THE HIGHER TERRAIN WITH AN ENHANCED LIKELIHOOD FOR AN
ACCELERATED SNOWMELT AND FLASH FLOODING OF CREEKS/STREAMS. GAVE SOME
CONSIDERATION TO A FLASH FLOOD WATCH...BUT WE DECIDED TO LET THE DAY
SHIFT TAKE ANOTHER LOOK AND SEE IF THEY CAN NARROW DOWN THE SPECIFIC
THREAT AREAS. WPC HAS MUCH OF OUR CWA IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL ON SATURDAY...SO FULLY EXPECT THAT FLOOD AND/OR FLASH FLOOD
WATCHES WILL BE NECESSARY SOON. BY LATE SATURDAY NIGHT...WBZ HEIGHTS
FINALLY DROP BELOW 10K FEET WHICH WOULD SUGGEST MOUNTAIN SNOW. COULD
SEE ADVISORY-LEVEL AMOUNTS IF THE CHANGEOVER OCCURS SOON ENOUGH OVER
THE SNOWY AND SIERRA MADRE RANGES.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 401 AM MDT FRI MAY 6 2016

WET PATTERN CONTINUES INTO SUNDAY AS THE UPPER LOW ESSENTIALLY
STALLS ACROSS SOUTHEAST WYOMING WITH HIGH CHANCE TO LIKELY POPS A
FAIRLY GOOD BET ACROSS THE ENTIRE FORECAST AREA. CONCERNS FOR
FLOOD POTENTIAL WILL CONTINUE INTO SUNDAY GIVEN COVERAGE OF RAIN
BUT COOLER TEMPERATURES SHOULD MEAN MORE SNOW IN THE HIGHER
ELEVATIONS VERSUS RAIN BY LATE IN THE WEEKEND. THE AIRMASS WILL
BE A BIT MORE STABILIZED ON SUNDAY DUE TO COOLER BOUNDARY
LAYER CONDITIONS...HOWEVER WE STILL EXPECT TO SEE THE POTENTIAL
FOR ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENING
HOURS. THE UPPER LOW FINALLY KICKS OUT TO THE NORTHEAST LATE
MONDAY WITH A DOWNWARD TREND IN POPS EXPECTED ACROSS THE SOUTHERN
ZONES TUESDAY WITH CHANCE POPS FOR SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE NORTHERN ZONES AHEAD OF THE NEXT
APPROACHING UPPER TROUGH MOVING DOWN FROM MONTANA. THAT TROUGH
MOVES EAST BY THURSDAY WITH SLIGHT CHANCE POPS EXPECTED GOING INTO
LATE WEEK. OVERALL NEXT WEEK LOOKS TO BE COOLER THAN WHAT WE HAVE
SEEN THE LATTER PART OF THIS WEEK WITH DAILY HIGH TEMPS GENERALLY
IN THE 40S-50S WEST AND 60S EAST. ELEVATIONS ABOVE 9500 FT LOOK
TO SEE HIGHS IN THE MID 30S TO AROUND 40 THROUGH THE WEEK...COOL
ENOUGH TO SLOW THE SNOWMELT PROCESS A BIT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 957 PM MDT THU MAY 5 2016

VFR...WITH CEILINGS LOWERING AFTER 00Z SATURDAY...WITH LOCALIZED
MVFR IN SHOWERS AT RAWLINS AND LARAMIE AFTER 00Z SATURDAY AND
CEILINGS LOWERING TO NEAR 5000 FEET AGL AT NEBRASKA TAF SITES.

&&

.FIRE WEATHER...
ISSUED AT 401 AM MDT FRI MAY 6 2016

COOLER AND WETTER PATTERN STILL PROJECTED TO SET UP ACROSS SE
WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH THE WEEKEND.
PATTERN BECOMES A BIT LESS ACTIVE FOR SHOWERS AND THUNDERSTORMS
BY MID WEEK WITH PROJECTED CONDITIONS EXPECTED TO REMAIN WELL
ABOVE ANY CRITICAL THRESHOLDS FOR FIRE WEATHER CONCERNS IN THE
FORSEEABLE FUTURE.

&&

.HYDROLOGY...
ISSUED AT 401 AM MDT FRI MAY 6 2016

WARM TEMPERATURES WILL CONTINUE TODAY WITH AFTERNOON HIGHS LIKELY IN
THE 50S IN THE HIGH ELEVATIONS OF THE SNOWY/SIERRA MADRE RANGES. MTN
CREEKS AND STREAMS WILL CONTINUE TO SEE NOTABLE RISES IN THE NEXT 24
TO 48 HOURS. WIDESPREAD THUNDERSTORMS COULD PRODUCE HEAVY RAIN TODAY
AND SATURDAY. RAIN ON SNOW COULD YIELD ACCELERATED SNOWMELT AND LEAD
TO FLASH FLOODING...ESPECIALLY OF MOUNTAIN CREEKS/STREAMS. THERE MAY
ALSO BE A THREAT FOR LOCALIZED FLASH FLOODING OVER THE PLAINS. FLASH
FLOOD WATCHES MAY BECOME NECESSARY SOON.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...CLH
LONG TERM...JG
AVIATION...RUBIN
FIRE WEATHER...JG
HYDROLOGY...CLH



  [top]

000
FXUS65 KRIW 060942
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
342 AM MDT FRI MAY 6 2016

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

GENERAL OMEGA BLOCK PATTERN ACROSS THE CONUS...WITH SLOW
MOVING/EVOLVING DEEP STORM SYSTEM MOVING OUT OF THE DESERT
SW...TOWARD THE CNTRL ROCKIES THRU THE FCST PERIOD...BECOMING PART
OF A POSSIBLE REX BLOCK SANDWICHED BETWEEN ANOTHER OMEGA BLOCK BY
SUNDAY. SFC CURRENTLY SHOWS HIGH P ACROSS THE GREAT BASIN WITH WEAK
LOW P OFF TO THE NE AND OVR ND...WITH A VERY WEAK TROF REACHING
INTO NERN WY.

ADDED ZONE 07 INTO THE FLOOD WATCH AREA AS COPIOUS RAINFALL OVR THE
OWL CREEK AND BRIDGER MOUNTAINS COULD BE PROBLEMATIC...AT THE VERY
LEAST PROVIDING THE IMPETUS FOR MUD AND ROCK SLIDE POTENTIAL IN THE
CANYON AREAS...IN ADDITION TO/OR IN LIEU OF FLOODING.

BOTTOM LINE...VERY WET PATTERN ABOUT DUE TO TAKE OVR NEARLY THE
ENTIRE FCST PERIOD...WITH FLOOD WATCHES POSTED FOR PORTIONS OF CNTRL
WY...INCLUDING ZONES 07 17 AND 18...BEGINNING SAT 12Z AND LASTING AT
LEAST THRU THE DAY SUNDAY.

AS THE SW CONUS LOW SLOWLY SPINS THIS WAY...PWS WILL INCREASE THRU
THE DAY...REACHING ANOMALOUSLY HIGH LEVELS BY TONIGHT...RANGING
BETWEEN 0.75 AND 1 INCH OVERNIGHT TONIGHT THRU SAT MORNING. COMBINED
WITH THE PASSAGE OF A DEVELOPING SFC FRONT TONIGHT...THIS WILL USHER
IN THE BEGINNING OF POTENTIAL FLOOD CONDITIONS BY SAT MORNING FOR
MUCH OF FREMONT COUNTY AND AT LEAST SOUTHERN HOT SPRINGS
COUNTY...AREAS FAVORED TO TAKE ADVANTAGE OF UPSLOPE CONDITIONS WITH
VIGOROUS VEERING FLOW FROM NE TO E/SFC TO H7. QPF VALUES/RANGES ARE
ACCORDINGLY HIGH WITH BETWEEN A HALF AND AND INCH EVER 6 HRS
BEGINNING TONIGHT UNTIL SAT MORNING...THEN PERHAPS A QUARTER INCH TO
A HALF INCH EVERY 6 HRS THRU SAT NIGHT. THIS WILL GIVE 2 DAY TOTAL
QFP VALUES RANGING FROM 2 TO 4 INCHES OVR THE CNTRL BASINS AND
ADJACENT MOUNTAINS. SNOWFALL WILL BE INTERESTING...ESPECIALLY DURING
THE OVERNIGHT HRS TONIGHT AND SATURDAY NIGHT...AS WARM ADVECTION
AHEAD OF THE APPROACH OF THE UPR LOW WILL KEEP SNOW LEVELS HIGH TO
BEGIN WITH...FALLING TO AROUND 8500 FEET OR SO BY SAT/SUN
MORNINGS...BUT OSCILLATING SOME BETWEEN THESE PERIODS AS THE WARM
ADVECTION BATTLES THE COLDER TEMPS NEAR THE CENTER OF THE LOW AS IT
APPROACHES. ADVISORY/WARNING ACCUMULATIONS WILL BE LIKELY OVR THE
WIND RIVER/SRN ABSAROKA MOUNTAINS THRU SUN MORNING...BUT MOST OF
HIGH AMOUNTS WILL BE LOCATED ABOVE 9500 FEET AND COME DURING THE TWO
NOCTURNAL PERIOD. WILL LET THE DAY CREW DECIDE HOW TO HANDLE THE
SNOW. FINALLY...WITH RATHER STRONG ACCENT SPREADING OVR THE FA WITH
THE APPROACH OF THE UPR LOW...THIS AFTERNOON MAY ALSO AFFORD CHANCES
FOR A FEW STRONG/MARGINALLY SEVERE THUNDERSTORMS WITH CAPE RANGING
FROM 500 TO 1500 J/KG ACROSS THE SRN AND ERN FA...COMBINING WITH
SHEAR RANGING FROM 25 TO 40 KTS BUT ONLY MARGINAL LAPSE RATES. A FEW
STORMS COULD PRODUCE STRONG WET DOWNBURSTS IN HEAVY RAIN AND SMALL
HAIL OF AROUND .75 INCH...TO SLIGHTLY LARGER. ACROSS SWEETWATER
COUNTY WHERE IT WILL BE A BIT DRIER IN THE BOUNDARY LAYER
EARLY...DCAPE COULD RANGE BETWEEN 500 AND 900 J/KG FOR A SHORT
PERIOD...PRODUCING A FEW STRONG MICROBURSTS APPROACHING SEVERE
LEVELS BY MID TO LATE AFTERNOON. ALL IN ALL..A VERY BUSY PATTERN
FOR THE NEXT FEW DAYS.

.LONG TERM...MONDAY THROUGH FRIDAY

THE MODELS KEEP SCATTERED SHOWERS AND ISOLATED STORMS ALONG AND
EAST OF THE DIVIDE MONDAY WITH DRIEST AREA BEING SW WY. THE NEXT
WEATHER SYSTEM DROPS SOUTHEAST OUT OF MONTANA MONDAY NIGHT AND
THROUGH WYOMING TUESDAY INTO TUE NIGHT. RAIN SHOWERS WITH SNOW IN
THE MOUNTAINS. RAIN COULD CHANGE TO SNOW BRIEFLY OVER THE LOWER
ELEVATIONS TUE NIGHT WITH LIGHT ACCUMULATION. WILL NEED TO WATCH
THIS MORE AS TIME GETS CLOSER. A NW FLOW ALOFT FOR WED AND THURS
WITH A MORE WEST FLOW ALOFT NEXT FRIDAY. THERE APPEARS TO BE A FEW
WEAK DISTURBANCES IN THE FLOW WED AND THURS WHICH WOULD LEAD TO
SOME CONVECTION BOTH DAYS. MOST OF THE ACTIVITY LOOKS TO BE ALONG
AND EAST OF THE DIVIDE WITH LESSER COVERAGE IN THE SOUTHWEST. NEXT
FRIDAY WOULD SEE BETTER SHOWER OR STORM COVERAGE WEST OF THE
DIVIDE VERSUS EAST OF THE DIVIDE. HIGH TEMPS WILL BE ON A YO-YO
RIDE WITH MONDAY BEING THE MILD DAY...THEN COLDER TUE AND WED. A
LITTLE WARMER NEXT THURS AND FRI.

&&

.AVIATION.../12Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

UPPER LOW ALONG THE SOUTHERN CALIFORNIA COAST WILL GRADUALLY TRACK
ONSHORE AND SPREAD MOISTURE NORTH ACROSS THE FORECAST AREA FRIDAY.
SHORTWAVE OVER EAST-CENTRAL UTAH WILL MAKE ITS WAY NORTH BY MIDDAY
FRIDAY AS COLD FRONT DROPS SOUTH TO THE EAST OF THE DIVIDE BEFORE
SWINGING AROUND THE WIND RIVER RANGE. THIS COMBINATION WILL SET THE
STAGE FOR SHOWERS AND THUNDERSTORMS...SOME POSSIBLY STRONG...AFTER
20Z/FRIDAY. MOISTURE DEEPENS DURING THE AFTERNOON AND INTO THE
EVENING HOURS. EXPECT WIDESPREAD MOUNTAIN OBSCURATIONS AFTER ABOUT
00Z/SATURDAY. HAVE KEPT LOW END VFR AT KRKS...KBPI...AND KPNA
BETWEEN 00Z-06Z/SATURDAY...ALTHOUGH MVFR WOULD BE A DISTINCT
POSSIBLITY. SURFACE WIND FROM THE EAST-NORTHEAST TO EAST-SOUTHEAST
OF 12-22KTS...HIGHER AT KRKS...WILL PROVIDE FAVORABLE SHEAR PROFILE
DURING THE AFTERNOON ACROSS SOUTHWEST WYOMING. HEAVIER PRECIPITATION
FROM 00Z-12Z/SATURDAY WILL BE SNOW ABOVE 9K FT MSL. BETTER CHANCE
FOR MVFR CEILINGS/VISIBILITY WILL COME BETWEEN 06Z-12Z/SATURDAY
BECAUSE OF BETTER DYNAMICS AND DEEPER MOISTURE. KJAC WILL BE THE
LEAST LIKELY LOCATION TO SEE MVFR CEILINGS AS UPPER FLOW IS NOT
AS FAVORABLE THERE.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

UPPER LOW WILL GRADUALLY TRACK ONSHORE ACROSS SOUTHERN CALIFORNIA
TODAY WHILE CONTINUING TO SPREAD MOISTURE NORTH ACROSS THE EASTERN
GREAT BASIN INTO WYOMING. AT THE SAME TIME...A COLD FRONT WILL PUSH
SOUTH FROM MONTANA THIS MORNING. THE FRONT WILL SWEEP THROUGH THE
BIG HORN BASIN BETWEEN 11Z-14Z WITH GUSTY NORTHERLY WIND OF 15-25KTS
IN ITS WAKE. THE FRONT WILL PUSH ACROSS THE WIND RIVER BASIN BETWEEN
15Z-17Z WITH GUSTY NORTHEAST WIND. THE WIND WILL INCREASE THIS
AFTERNOON AT ALL TERMINALS AS PRESSURE GRADIENT TIGHTENS. BEST
CHANCE FOR STRONG CONVECTION WILL BE TO THE SOUTH OF A KRIW-KCPR LINE
AFTER 20Z/FRIDAY. MOISTURE DEEPENS AND MODEL SOUNDINGS SHOW ATMOSPHERE
QUICKLY SATURATING BETWEEN 23Z/FRIDAY AND 03Z/SATURDAY...PARTICULARLY
AT KLND...KRIW...AND KCPR. EXPECT WIDESPREAD MVFR WITH LOCALIZED IFR
CONDITIONS NEAR THE FOOTHILLS. MOUNTAINS WILL BE OBSCURED THROUGH THE
REMAINDER OF THE FORECAST PERIOD. IFR/MVFR CEILINGS/VISIBILITY WILL
BECOME MORE WIDESPREAD BETWEEN 06Z-12Z/SATURDAY. PRECIPITATION AMOUNTS
0.50 INCHES IN 6-HOURS...DYNAMICS ARE FAVORABLE...AND UPSLOPE
FLOW WILL ENHANCE PRECIPITATION PRODUCTION.

&&

.FIRE WEATHER...

LOW FIRE DANGER FOR ALL LOCATIONS THROUGH THE WEEKEND...WITH GREEN
UP UNDERWAY AND MORE MOISTURE HEADED INTO THE REGION OVER THE NEXT
FEW DAYS. EXPECT RELATIVELY HIGH MINIMUM RH VALUES...ONLY BOTTOMING
OUT IN THE 30S TO MID 60S (PERCENT) ACROSS THE ENTIRE REGION.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN ALSO BE EXPECTED
BY THIS AFTERNOON...WITH SHOWERS...HEAVY AT TIMES...CONTINUING TO
FALL OVER MOST LOCATIONS THROUGH AT LEAST SUNDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY AFTERNOON FOR
WYZ007-017-018.

&&

$$

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




000
FXUS63 KUNR 060836
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
236 AM MDT FRI MAY 6 2016

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 229 AM MDT FRI MAY 6 2016

08Z SURFACE ANALYSIS HAD COLD FRONT FROM NORTHEAST ND INTO
SOUTHEAST MT TO NORTHWEST WY...PUSHING SLOWLY SOUTHEAST AS SURFACE
HIGH OVER SOUTHWEST CANADA NOSES INTO THE NORTHERN PLAINS/ROCKIES.
LOW LEVEL JET AHEAD OF COLD FRONT STRUGGLING TO PRODUCE ACCAS AT
THIS POINT...BUT MAY YET STILL DEVELOP BEFORE SUNRISE. WATER
VAPOUR SHOWED UPPER LOW OFF CA COAST...AND THIS WILL BE THE MAIN
WEATHER MAKER IN THE SHORT TERM.

TODAY/TONIGHT...UPPER LOW MOVES INTO THE FOUR CORNERS AREA BY 12Z
SATURDAY AS NOSE OF 120KT JET AT BASE OF UPPER LOW PUSHES INTO CO.
DIVERGENCE ON NOSE OF JET WILL PRODUCE SYNOPTIC LIFT OVER CO/WY
TODAY...SPREADING INTO CWA LATE THROUGH THIS EVENING. SURFACE
COLD FRONT SLIDES SOUTHEAST INTO NE THIS EVENING WITH
NORTHEASTERLY BOUNDARY LAYER FLOW BEHIND IT. UPSLOPE FLOW
COMBINES WITH UPSIDENCE UNDER DIVERGENCE TO PRODUCE HIGH POPS
ALONG FRONTAL BOUNDARY FROM WY INTO SOUTHWEST SD TONIGHT. FOR THIS
AFTERNOON...UP TO 1500J/KG MLCAPE WITH LITTLE MLCIN POOLS AHEAD OF
COLD FRONT. SHOULD SEE TSRA DEVELOP LATE THIS AFTERNOON OVER
WY/HIGHER TERRAIN AND PERSIST INTO THE EVENING HOURS AS IT SPREADS
EAST/NORTH. GIVEN MODEST INSTABILITY AND 0-6KM EFFECTIVE
SHEAR...SUSPECT AN ISOLATED SEVERE TSRA OR TWO MAY DEVELOP OVER
SOUTHWEST QUARTER OF CWA DURING/SHORTLY AFTER PEAK INSOLATION.
MARGINAL HAIL/SEVERE WIND GUSTS POSSIBLE. TEMPERATURES
TODAY/TONIGHT WILL BE NEAR GUIDANCE.

SATURDAY...UPPER LOW MOVES THROUGH CO INTO SOUTH CENTRAL WY.
AFOREMENTIONED FORCING WANES IN THE MORNING AS DRIER AIR CIRCULATES
INTO CWA FROM THE EASTERN DAKOTAS. BY AFTERNOON...SURFACE LOW
DEVELOPS OVER WESTERN NE IN RESPONSE TO ENERGY ROTATING AROUND
UPPER LOW. FLOW TURNS SOUTHEAST WITH MOISTURE RETURN. POPS
INCREASE LATER IN THE DAY AND INTO THE NIGHT ACROSS SOUTHERN
PORTIONS OF THE CWA AS WEAK INSTABILITY COMBINES WITH SYNOPTIC
SCALE LIFT. TEMPERATURES WILL BE NEAR GUIDANCE.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 229 AM MDT FRI MAY 6 2016

THE GREAT BASIN UPPER LOW WILL SLOWLY SLIDE TOWARD THE REGION
THROUGH THE FIRST HALF OF NEXT WEEK AS A TROUGH MOVES INTO THE NRN
ROCKIES. THIS SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
THROUGH TUESDAY TO WEDNESDAY. RIGHT NOW THE BEST CHANCES FOR
SHOWERS WILL BE SUNDAY THROUGH TUESDAY. THIS SYSTEM WILL ALSO
BRING NEAR TO SLIGHTLY BELOW AVERAGE TEMPS. SLIGHTLY DRIER WEATHER
IS EXPECTED PAST MIDWEEK...BUT UNCERTAINTY REMAINS WITH THIS TYPE
OF PATTERN.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT
ISSUED AT 229 AM MDT FRI MAY 6 2016

THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
TONIGHT. THE BEST CHANCES WILL BE ACROSS NORTHEAST WYOMING...THE
BLACK HILLS AREA...AND SOUTHWEST SOUTH DAKOTA. MVFR CONDITIONS ARE
POSSIBLE NEAR ANY PRECIP. OTHERWISE VFR CONDITIONS ARE EXPECTED.
WINDS WILL BECOME BREEZY FROM THE NORTH TO NORTHEAST TODAY.

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13




000
FXUS65 KRIW 060528
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1128 PM MDT THU MAY 5 2016

.SHORT TERM...TONIGHT THROUGH SUNDAY

HIGH CLOUDS HAVE ENCROACHED ON THE AREA TODAY. A HARBINGER OF THE
MAJOR CHANGE THAT IS TAKING SHAPE FOR FRIDAY THROUGH THE WEEKEND.
A FEW WEAK SHOWERS ARE STARTING TO FORM AND MAIN THREAT INTO EARLY
THIS EVENING WILL BE GUSTY WIND POTENTIAL WITH AREAS OF 40-50
DEGREE SPREADS IN THE SOUTHWEST. A FEW DYING GUSTY SHOWERS MAY
EDGE EAST OF THE DIVIDE INTO EARLY THIS EVENING. NOT MUCH LIQUID
BUT SOME BRIEF STRONG WIND GUSTS AND A LIGHTNING STRIKE OR TWO. FRIDAY
IS STILL SHAPING UP TO BE QUITE THE INTERESTING DAY. LARGE UPPER
LOW MOVES INTO SOCAL WHILE SRN CANADA SHORTWAVE PUSHES A COLD
FRONT SWD ACROSS THE AREA. UPPER LOW DYNAMICS START TO PUSH INTO
THE SOUTH WITH A RATHER COMPLEX JET INTERACTION. SWRN WYOMING WILL
SEE THE DAYTIME HEATING...APPROACHING FRONT...LARGE SCALE ASCENT
WITH UPPER LOW AND POSSIBLE UPPER JET SUPPORT. JET SUPPORT IS
QUITE INTERESTING AS FIRST JET STREAK MOVES UP AND STARTS TO
ROTATE WWD ACROSS SRN ID/NRN UT AREA WHILE MAIN CYCLONIC NOSE OF
THE JET NOSES INTO FAR NRN CO. THIS SETUP PUTS SWRN WYOMING IN
POTENTIAL STRONG UPPER DIVERGENCE. NORTH OF THE FRONT...WE CAN
STILL SEE SOME STRONGER STORMS WITH GOOD DIRECTIONAL SHEAR AND
MODERATE CAPE. MARGINAL RISK HAS BEEN MOVED TO INCLUDE CASPER AND
LANDER AND IS PRETTY MUCH WHERE WE`VE HAD IT FOR 3 DAYS NOW. AS
THE UPPER LOW MOVES SLOWLY NEWD FRIDAY NIGHT...WE SHOULD SEE
SIGNIFICANT LOWER ELEVATION RAIN AROUND PARTS OF SWRN AND MOST OF
CENTRAL WYOMING...CENTERED AROUND THE WIND RIVER BASIN/LANDER
FOOTHILLS AND SURROUNDING MOUNTAINS. FRONT PUSHES SOUTH FRIDAY
PROVIDING UPSLOPE WHILE MID LEVEL E-SE FLOW CONVEYOR BELT AND
ASSOCIATED LIFT... SATURATES THE ATMOSPHERE. MID LEVEL QG FORCING
AND UPPER JET SUPPORT FOR THE FIRST HALF OF THE EVENT ALL SPELLS
SIGNIFICANT PCPN. SNOW LEVELS LOOK MAYBE A TAD LOWER THAN
YESTERDAY. THINKING 9-9.5K IN THE WINDS AT 06Z SATURDAY WITH ABOUT
1K LOWER AT TIMES IN HEAVIER SHOWERS/TSTMS. 12Z SATURDAY MORNING
SNOW LEVELS WILL PROBABLY BE CLOSE TO 8500 FEET WITH SOME LOWERING
AT TIMES IN HEAVIER PCPN. THINKING LANDER WILL DROP INTO THE 41-44
DEGREE RANGE BY SATURDAY MORNING AND THEN THINKING ABOUT 3 DEGREES
COOLER PER 1K FEET. HIGHS IN LND WILL PROBABLY ONLY BE IN THE
46-48 RANGE WITH SNOW LEVELS 8.5K GENERALLY WITH SOME LOWERING IN
HEAVIER PCPN PERIODS. ANOTHER 500 FEET OR SO LOWER SATURDAY NIGHT
AS LOW GETS CLOSER. STILL LOOKING AT 1 TO 2 INCHES ACROSS THE WIND
RIVER BASIN WITH THE HIGHER AMOUNTS FROM AROUND RIVERTON WWD WITH
2.5-3 INCHES TOWARDS LANDER AND 3-4 IN THE WINDS AND POSSIBLY SRN
ABSAROKAS. HEAVY SNOW WILL FALL BUT MOSTLY ABOVE 10K INITIALLY AND
THEN GRADUALLY A LITTLE LOWER. 1-2 FEET OF SNOW WILL CERTAINLY
FALL UP HIGH BUT MOSTLY ABOVE ROAD LEVEL. OTHER SURROUNDING AREAS
WILL ALSO SEE THE POTENTIAL FOR .75 TO 1.5 INCHES OF RAIN FROM THE
SWRN AREAS TO CODY FOOTHILLS AND OVER TO NATRONA AND JOHNSON
COUNTY AND EVEN IN SWEETWATER COUNTY. THE LEAST WILL PROBABLY BE
THE FAR NWRN AREAS AND NR5N BIGHORN BASIN WHERE AMOUNTS WILL VARY
FROM A THIRD TO TWO-THIRDS IN GENERAL. STILL UNSETTLED SUNDAY WITH
UPPER LOW LIKELY TO BE WEAKENING AND MEANDERING JUST TO OUR SOUTH.
HARD TO FCST WHERE BANDS OF PCPN WILL BE BY THEN. THEY COULD BE
CLOSER AROUND THE LOW TO MAYBE SOME OUTER BANDS WILL COME INTO
PLAY. MOST AREAS WILL HAVE A CHANCE OF CONTINUED SHOWERS AND
HIGHER ELEVATION SNOW THROUGH THE END OF THIS PERIOD. BOTTOM
LINE...A MAJOR CHANGE FROM WARM AND DRY TO COOL/COLD AND WET (AND
WHITE UP HIGH) WITH A COUPLE (TO SEVERAL) INCHES OF LIQUID
CENTERED ON FREMONT COUNTY WITH LESS AS YOU FAN OUT FROM THERE.
HIGHS IN THE 70S AND 80S WILL STRUGGLE TO BE IN THE UPPER 40S TO
UPPER 50S ON FRIDAY FOR MANY LOWER ELEVATION AREAS.

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY

A SERIES OF LOW PRESSURE TROUGHS IN NORTH NORTHWEST FLOW WILL DIG
SOUTH SOUTHEAST FROM BRITISH COLUMBIA AND ALBERTA MOVING ACROSS
WESTERN MONTANA...EASTERN IDAHO AND WESTERN WYOMING BRINGING PERIODS
OF SHOWERS AND AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE
PERIOD.  TEMPERATURES WILL BE COOL AND MOST PERIODS TEMPERATURES ARE
COOLER THAN PREVIOUS FORECAST.  THE TREND IS FOR LESS PRECIPITATION
WEDNESDAY THROUGH THURSDAY BUT STILL SHOWERS AND THUNDERSTORMS WILL
BE MOVING THROUGH THE AREA WHILE BEING MOST NUMEROUS IN THE WESTERN
AND NORTHERN MOUNTAINS.

&&

.AVIATION.../06Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

UPPER LOW ALONG THE SOUTHERN CALIFORNIA COAST WILL GRADUALLY TRACK
ONSHORE AND SPREAD MOISTURE NORTH ACROSS THE FORECAST AREA FRIDAY.
SHORTWAVE OVER EAST-CENTRAL UTAH WILL MAKE ITS WAY NORTH BY MIDDAY
FRIDAY AS COLD FRONT DROPS SOUTH TO THE EAST OF THE DIVIDE BEFORE
SWINGING AROUND THE WIND RIVER RANGE. THIS COMBINATION WILL SET THE
STAGE FOR SHOWERS AND THUNDERSTORMS...SOME POSSIBLY STRONG...AFTER
20Z/FRIDAY. MOISTURE DEEPENS DURING THE AFTERNOON AND INTO THE
EVENING HOURS. EXPECT WIDESPREAD MOUNTAIN OBSCURATIONS AFTER ABOUT
00Z/SATURDAY. HAVE KEPT LOW END VFR AT KRKS...KBPI...AND KPNA
BETWEEN 00Z-06Z/SATURDAY...ALTHOUGH MVFR WOULD BE A DISTINCT
POSSIBLITY. SURFACE WIND FROM THE EAST-NORTHEAST TO EAST-SOUTHEAST
OF 12-22KTS...HIGHER AT KRKS...WILL PROVIDE FAVORABLE SHEAR PROFILE
DURING THE AFTERNOON ACROSS SOUTHWEST WYOMING. HEAVIER PRECIPITATION
FRIDAY EVENING WILL BE SNOW ABOVE 9K FT MSL.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

UPPER LOW WILL GRADUALLY TRACK ONSHORE ACROSS SOUTHERN CALIFORNIA
TODAY WHIL CONTINUING TO SPREAD MOISTURE NORTH ACROSS THE EASTERN
GREAT BASIN INTO WYOMING. AT THE SAME TIME...A COLD FRONT WILL PUSH
SOUTH FROM MONTANA THIS MORNING. THE FRONT WILL SWEEP THROUGH THE
BIG HORN BASIN BETWEEN 11Z-14Z WITH GUSTY NORTHERLY WIND OF 15-25KTS
IN ITS WAKE. THE FRONT WILL PUSH ACROSS THE WIND RIVER BASIN BETWEEN
15Z-17Z WITH GUSTY NORTHEAST WIND. THE WIND WILL INCREASE THIS
AFTERNOON AT ALL TERMINALS AS PRESSURE GRADIENT TIGHTENS. BEST
CHANCE FOR STRONG CONVECTION WILL BE TO THE SOUTH OF A KRIW-KCPR
LINE AFTER 20Z/FRIDAY. MOISTURE DEEPENS AND MODEL SOUNDINGS SHOW
ATMOSPHERE QUICKLY SATURATING BETWEEN 23Z/FRIDAY AND
03Z/SATURDAY...PARTICULARLY AT KLND...KRIW...AND KCPR. EXPECT
WIDESPREAD MVFR WITH LOCALIZED IFR CONDITIONS NEAR THE FOOTHILLS.
MOUNTAINS WILL BE OBSCURED THROUGH THE REMAINDER OF THE FORECAST
PERIOD. HEAVIER PRECIPITATION FRIDAY EVENING WILL BE SNOW ABOVE 9K
FT MSL.

&&

.FIRE WEATHER...

AN AREA OF LOW PRESSURE WILL MOVE TOWARD WYOMING OVER THE NEXT FEW
DAYS AND BRING INCREASINGLY COOL AND WET WEATHER. A FEW AFTERNOON
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE WESTERN MOUNTAINS THIS
AFTERNOON. MEANWHILE...AREAS EAST OF THE DIVIDE WILL SEE ONE MORE
WARM AND DRY DAY WITH A SOUTHWESTERLY BREEZE DEVELOPING. SOME AREAS
WILL HAVE RELATIVE HUMIDITY FALL INTO THE LOWER TEENS. WET WEATHER
WILL RETURN FRIDAY AND ESPECIALLY FRIDAY NIGHT INTO SATURDAY WITH A
WETTING RAIN LIKELY FOR MANY AREAS...ESPECIALLY EAST OF THE DIVIDE.


&&

.RIW WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY AFTERNOON FOR
WYZ007-017-018.

&&

$$

SHORT TERM...PS
LONG TERM...C.BAKER
AVIATION...CNJ
FIRE WEATHER...PS




000
FXUS63 KUNR 060505
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1105 PM MDT THU MAY 5 2016

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 220 PM MDT THU MAY 5 2016

AFTN SFC ANALYSIS SHOWS SOUTHERLY WINDS HAVE DEVELOPED MUCH OF THE
REGION DUE TO THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
CENTRAL CONUS AND LOW PRESSURE EXTENDING FROM CENTRAL MANITOBA
ACROSS MONTANA AND THEN INTO THE FOUR CORNERS REGION. SUNNY SKIES
AND SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGE HAS HELPED TO PUSH
TEMPERATURES INTO THE UPPER 70S TO MID 80S OVER THE FORECAST AREA.
MODELS ARE SHOWING 500-1000J/KG CAPE OVER THE BLACK HILLS AND
PARTS OF THE WESTERN SOUTH DAKOTA PLAINS HOWEVER SUBSIDENCE AND
RELATIVELY WARM AIR ALOFT WILL KEEP ANY THUNDERSTORMS FROM
DEVELOPING THIS AFTN/EVE.

TONIGHT...A 35-45KT LOW LEVEL JET WILL DEVELOP FROM SOUTHWESTERN
INTO NORTHEASTERN SOUTH DAKOTA. THERE MAY BE SOME BREEZY
CONDITIONS OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS TONIGHT. THETA-E
ADVECTION WILL REMAIN RATHER WEAK HOWEVER SOME ACCAS MAY
FORM...BUT WITH RATHER DRY LOWER LEVELS EXPECT ONLY VIRGA TO
RESULT.

ON FRIDAY...THE UPPER RIDGE WILL MOVE OFF TO THE EAST AS A COLD
FRONT DROPS SOUTHWARD INTO THE FORECAST AREA. MOISTURE POOLING
ALONG BOUNDARY DURING PEAK HEATING...ESPECIALLY OVER SOUTHERN HALF
OF CWA...WILL RESULT IN 500- 1000J/KG MLCAPE AND WEAK 0-6KM BULK
SHEAR. MLCIN WEAK ENOUGH TO ALLOW TSRA TO DEVELOP IN THE AFTERNOON
AHEAD OF SHORTWAVE MOVING ACROSS CO INTO WY...WHICH IS AHEAD OF
UPPER LOW SPINNING OVER CA/NV. TEMPERATURES WILL BE TRICKY WITH
CLOUD COVER/PRECIPITATION COVERAGE AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

A LARGE UPPER LEVEL LOW LIFTS OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS
EASTWARD ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER
LOWS PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES BY MONDAY. THIS
WILL LEAD TO AN UNSETTLED AND WET WEATHER PATTERN...WITH DAILY
CHANCES FOR SHOWERS AND SOME ISOLATED THUNDERSTORMS. NEAR SEASONAL
TEMPERATURES ARE EXPECTED THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1101 PM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY AFTERNOON. A COLD FRONT
WILL CROSS NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA FRIDAY
MORNING...AND INTO SOUTHWEST SOUTH DAKOTA FRIDAY AFTERNOON. GUSTY
NORTH WINDS WILL DEVELOP BEHIND THE FRONT. SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS NORTHEAST WYOMING INTO WESTERN
SOUTH DAKOTA FRIDAY AFTERNOON AND EVENING...WITH MVFR/LCL IFR
CONDITIONS WITH THE THUNDERSTORMS.

&&

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

$$

SHORT TERM...10
LONG TERM...15
AVIATION...7




000
FXUS65 KCYS 060359
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
959 PM MDT THU MAY 5 2016

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM MDT THU MAY 5 2016

QUIET WEATHER WILL CONTINUE FOR ONE MORE NIGHT ACROSS THE CWA WITH
JUST SOME HIGH CLOUDINESS PASSING ACROSS THE REGION. UPPER RIDGE
AXIS CURRENTLY OVER THE HIGH PLAINS WILL MOVE SLOWLY EAST
OVERNIGHT LEAVING THE CWA UNDER AN INCREASINGLY MOIST SOUTHERLY
FLOW ALOFT AHEAD OF AN UPPER LOW THAT WILL MOVE INTO SOUTHERN
CALIFORNIA FRIDAY. AN INITIAL UPPER IMPULSE WILL LIFT NORTH ACROSS
THE AREA LATE FRIDAY AND SHOULD SET OFF SCATTERED SHOWERS AND A
FEW STORMS OVER MAINLY SOUTHEAST WYOMING FRIDAY AFTERNOON...
CONTINUING INTO THE EVENING BEFORE BECOMING MORE ISOLATED FRIDAY
NIGHT. A BIT COOLER TEMPS FRIDAY GIVEN MORE CLOUD COVER BUT STILL
WARM. A MORE SIGNIFICANT LOBE OF ENERGY LOOKS TO ROTATE NORTH
ACROSS THE AREA LATER SATURDAY WITH A DEEPER MOIST SE TO EASTERLY
FLOW SO MORE SIGNIFICANT PRECIPITATION A DISTINCT POSSIBILITY. A
FEW STORMS POSSIBLE OVER THE SOUTHERN CWA BUT BETTER SHEAR AND
INSTABILITY SHOULD STAY TO THE SOUTH.  WILL HAVE TO WATCH FOR
POTENTIALLY HEAVY RAINS ESPECIALLY CLOSER TO THE COLORADO BORDER
WITH SNOW LEVELS DROPPING TO AROUND 8-9KFT SATURDAY NIGHT. DECENT
SNOWFALL A POSSIBILITY OVER THE HIGHER MTNS SATURDAY NIGHT AS
WELL.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 340 PM MDT THU MAY 5 2016

THE UPPER LOW WILL REMAIN OVERHEAD ON SUNDAY ALONG WITH
PERSISTENT ALBEIT SOMEWHAT WEAKER UPSLOPE FLOW...BRINGING A
CONTINUED CHANCE FOR SHOWERS AND A FEW T-STORMS THROUGH THE DAY.
THIS UPPER LOW WILL SHIFT EAST FOR MONDAY...HOWEVER ANOTHER UPPER
SHORTWAVE DIVING SOUTHWEST FROM CANADA WILL BRING A RENEWED
CHANCE FOR SHOWERS AND AFTERNOON T-STORMS ON MONDAY. OVERALL
PRECIP TOTALS LOOK LESS WITH THIS SYSTEM DUE TO THE DISCONNECT
WITH GULF MOISTURE. TUE/WED WILL CONTINUE TO BE SHOWERY AS THIS
UPPER TROUGH SLOWLY MOVES EASTWARD ACROSS THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 957 PM MDT THU MAY 5 2016

VFR...WITH CEILINGS LOWERING AFTER 00Z SATURDAY...WITH LOCALIZED
MVFR IN SHOWERS AT RAWLINS AND LARAMIE AFTER 00Z SATURDAY AND
CEILINGS LOWERING TO NEAR 5000 FEET AGL AT NEBRASKA TAF SITES.

&&

.FIRE WEATHER...
ISSUED AT 340 PM MDT THU MAY 5 2016

NO CONCERNS SEEN THROUGH THE WEEKEND WITH COOLER AND WETTER
CONDITIONS RETURNING TO THE AREA.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 060359
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
959 PM MDT THU MAY 5 2016

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM MDT THU MAY 5 2016

QUIET WEATHER WILL CONTINUE FOR ONE MORE NIGHT ACROSS THE CWA WITH
JUST SOME HIGH CLOUDINESS PASSING ACROSS THE REGION. UPPER RIDGE
AXIS CURRENTLY OVER THE HIGH PLAINS WILL MOVE SLOWLY EAST
OVERNIGHT LEAVING THE CWA UNDER AN INCREASINGLY MOIST SOUTHERLY
FLOW ALOFT AHEAD OF AN UPPER LOW THAT WILL MOVE INTO SOUTHERN
CALIFORNIA FRIDAY. AN INITIAL UPPER IMPULSE WILL LIFT NORTH ACROSS
THE AREA LATE FRIDAY AND SHOULD SET OFF SCATTERED SHOWERS AND A
FEW STORMS OVER MAINLY SOUTHEAST WYOMING FRIDAY AFTERNOON...
CONTINUING INTO THE EVENING BEFORE BECOMING MORE ISOLATED FRIDAY
NIGHT. A BIT COOLER TEMPS FRIDAY GIVEN MORE CLOUD COVER BUT STILL
WARM. A MORE SIGNIFICANT LOBE OF ENERGY LOOKS TO ROTATE NORTH
ACROSS THE AREA LATER SATURDAY WITH A DEEPER MOIST SE TO EASTERLY
FLOW SO MORE SIGNIFICANT PRECIPITATION A DISTINCT POSSIBILITY. A
FEW STORMS POSSIBLE OVER THE SOUTHERN CWA BUT BETTER SHEAR AND
INSTABILITY SHOULD STAY TO THE SOUTH.  WILL HAVE TO WATCH FOR
POTENTIALLY HEAVY RAINS ESPECIALLY CLOSER TO THE COLORADO BORDER
WITH SNOW LEVELS DROPPING TO AROUND 8-9KFT SATURDAY NIGHT. DECENT
SNOWFALL A POSSIBILITY OVER THE HIGHER MTNS SATURDAY NIGHT AS
WELL.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 340 PM MDT THU MAY 5 2016

THE UPPER LOW WILL REMAIN OVERHEAD ON SUNDAY ALONG WITH
PERSISTENT ALBEIT SOMEWHAT WEAKER UPSLOPE FLOW...BRINGING A
CONTINUED CHANCE FOR SHOWERS AND A FEW T-STORMS THROUGH THE DAY.
THIS UPPER LOW WILL SHIFT EAST FOR MONDAY...HOWEVER ANOTHER UPPER
SHORTWAVE DIVING SOUTHWEST FROM CANADA WILL BRING A RENEWED
CHANCE FOR SHOWERS AND AFTERNOON T-STORMS ON MONDAY. OVERALL
PRECIP TOTALS LOOK LESS WITH THIS SYSTEM DUE TO THE DISCONNECT
WITH GULF MOISTURE. TUE/WED WILL CONTINUE TO BE SHOWERY AS THIS
UPPER TROUGH SLOWLY MOVES EASTWARD ACROSS THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 957 PM MDT THU MAY 5 2016

VFR...WITH CEILINGS LOWERING AFTER 00Z SATURDAY...WITH LOCALIZED
MVFR IN SHOWERS AT RAWLINS AND LARAMIE AFTER 00Z SATURDAY AND
CEILINGS LOWERING TO NEAR 5000 FEET AGL AT NEBRASKA TAF SITES.

&&

.FIRE WEATHER...
ISSUED AT 340 PM MDT THU MAY 5 2016

NO CONCERNS SEEN THROUGH THE WEEKEND WITH COOLER AND WETTER
CONDITIONS RETURNING TO THE AREA.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 052338
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
538 PM MDT THU MAY 5 2016

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM MDT THU MAY 5 2016

QUIET WEATHER WILL CONTINUE FOR ONE MORE NIGHT ACROSS THE CWA WITH
JUST SOME HIGH CLOUDINESS PASSING ACROSS THE REGION. UPPER RIDGE
AXIS CURRENTLY OVER THE HIGH PLAINS WILL MOVE SLOWLY EAST
OVERNIGHT LEAVING THE CWA UNDER AN INCREASINGLY MOIST SOUTHERLY
FLOW ALOFT AHEAD OF AN UPPER LOW THAT WILL MOVE INTO SOUTHERN
CALIFORNIA FRIDAY. AN INITIAL UPPER IMPULSE WILL LIFT NORTH ACROSS
THE AREA LATE FRIDAY AND SHOULD SET OFF SCATTERED SHOWERS AND A
FEW STORMS OVER MAINLY SOUTHEAST WYOMING FRIDAY AFTERNOON...
CONTINUING INTO THE EVENING BEFORE BECOMING MORE ISOLATED FRIDAY
NIGHT. A BIT COOLER TEMPS FRIDAY GIVEN MORE CLOUD COVER BUT STILL
WARM. A MORE SIGNIFICANT LOBE OF ENERGY LOOKS TO ROTATE NORTH
ACROSS THE AREA LATER SATURDAY WITH A DEEPER MOIST SE TO EASTERLY
FLOW SO MORE SIGNIFICANT PRECIPITATION A DISTINCT POSSIBILITY. A
FEW STORMS POSSIBLE OVER THE SOUTHERN CWA BUT BETTER SHEAR AND
INSTABILITY SHOULD STAY TO THE SOUTH.  WILL HAVE TO WATCH FOR
POTENTIALLY HEAVY RAINS ESPECIALLY CLOSER TO THE COLORADO BORDER
WITH SNOW LEVELS DROPPING TO AROUND 8-9KFT SATURDAY NIGHT. DECENT
SNOWFALL A POSSIBILITY OVER THE HIGHER MTNS SATURDAY NIGHT AS
WELL.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 340 PM MDT THU MAY 5 2016

THE UPPER LOW WILL REMAIN OVERHEAD ON SUNDAY ALONG WITH
PERSISTENT ALBEIT SOMEWHAT WEAKER UPSLOPE FLOW...BRINGING A
CONTINUED CHANCE FOR SHOWERS AND A FEW T-STORMS THROUGH THE DAY.
THIS UPPER LOW WILL SHIFT EAST FOR MONDAY...HOWEVER ANOTHER UPPER
SHORTWAVE DIVING SOUTHWEST FROM CANADA WILL BRING A RENEWED
CHANCE FOR SHOWERS AND AFTERNOON T-STORMS ON MONDAY. OVERALL
PRECIP TOTALS LOOK LESS WITH THIS SYSTEM DUE TO THE DISCONNECT
WITH GULF MOISTURE. TUE/WED WILL CONTINUE TO BE SHOWERY AS THIS
UPPER TROUGH SLOWLY MOVES EASTWARD ACROSS THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 536 PM MDT THU MAY 5 2016

VFR WITH SCATTERED TO BROKEN CLOUDS AT OR ABOVE 10000 FEET AGL...
EXCEPT FOR ISOLATED TO SCATTERED SHOWERS AT WYOMING TAF SITES
AFTER 18Z FRIDAY WITH BROKEN CEILINGS FROM 3000 TO 5000 FEET AGL.

&&

.FIRE WEATHER...
ISSUED AT 340 PM MDT THU MAY 5 2016

NO CONCERNS SEEN THROUGH THE WEEKEND WITH COOLER AND WETTER
CONDITIONS RETURNING TO THE AREA.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS63 KUNR 052251
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
451 PM MDT THU MAY 5 2016

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 220 PM MDT THU MAY 5 2016

AFTN SFC ANALYSIS SHOWS SOUTHERLY WINDS HAVE DEVELOPED MUCH OF THE
REGION DUE TO THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
CENTRAL CONUS AND LOW PRESSURE EXTENDING FROM CENTRAL MANITOBA
ACROSS MONTANA AND THEN INTO THE FOUR CORNERS REGION. SUNNY SKIES
AND SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGE HAS HELPED TO PUSH
TEMPERATURES INTO THE UPPER 70S TO MID 80S OVER THE FORECAST AREA.
MODELS ARE SHOWING 500-1000J/KG CAPE OVER THE BLACK HILLS AND
PARTS OF THE WESTERN SOUTH DAKOTA PLAINS HOWEVER SUBSIDENCE AND
RELATIVELY WARM AIR ALOFT WILL KEEP ANY THUNDERSTORMS FROM
DEVELOPING THIS AFTN/EVE.

TONIGHT...A 35-45KT LOW LEVEL JET WILL DEVELOP FROM SOUTHWESTERN
INTO NORTHEASTERN SOUTH DAKOTA. THERE MAY BE SOME BREEZY
CONDITIONS OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS TONIGHT. THETA-E
ADVECTION WILL REMAIN RATHER WEAK HOWEVER SOME ACCAS MAY
FORM...BUT WITH RATHER DRY LOWER LEVELS EXPECT ONLY VIRGA TO
RESULT.

ON FRIDAY...THE UPPER RIDGE WILL MOVE OFF TO THE EAST AS A COLD
FRONT DROPS SOUTHWARD INTO THE FORECAST AREA. MOISTURE POOLING
ALONG BOUNDARY DURING PEAK HEATING...ESPECIALLY OVER SOUTHERN HALF
OF CWA...WILL RESULT IN 500- 1000J/KG MLCAPE AND WEAK 0-6KM BULK
SHEAR. MLCIN WEAK ENOUGH TO ALLOW TSRA TO DEVELOP IN THE AFTERNOON
AHEAD OF SHORTWAVE MOVING ACROSS CO INTO WY...WHICH IS AHEAD OF
UPPER LOW SPINNING OVER CA/NV. TEMPERATURES WILL BE TRICKY WITH
CLOUD COVER/PRECIPITATION COVERAGE AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

A LARGE UPPER LEVEL LOW LIFTS OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS
EASTWARD ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER
LOWS PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES BY MONDAY. THIS
WILL LEAD TO AN UNSETTLED AND WET WEATHER PATTERN...WITH DAILY
CHANCES FOR SHOWERS AND SOME ISOLATED THUNDERSTORMS. NEAR SEASONAL
TEMPERATURES ARE EXPECTED THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 450 PM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH TONIHT A STRONG COLD FRONT
WILL ENTER THE NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA
FRIDAY MORNING...WITH SURFACE WINDS SWITCHING TO THE NORTH AND
INCREASING AROUND 20 KTS.

&&

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

$$

SHORT TERM...10
LONG TERM...15
AVIATION...77




000
FXUS65 KCYS 052141
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
341 PM MDT THU MAY 5 2016

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM MDT THU MAY 5 2016

QUIET WEATHER WILL CONTINUE FOR ONE MORE NIGHT ACROSS THE CWA WITH
JUST SOME HIGH CLOUDINESS PASSING ACROSS THE REGION. UPPER RIDGE
AXIS CURRENTLY OVER THE HIGH PLAINS WILL MOVE SLOWLY EAST
OVERNIGHT LEAVING THE CWA UNDER AN INCREASINGLY MOIST SOUTHERLY
FLOW ALOFT AHEAD OF AN UPPER LOW THAT WILL MOVE INTO SOUTHERN
CALIFORNIA FRIDAY. AN INITIAL UPPER IMPULSE WILL LIFT NORTH ACROSS
THE AREA LATE FRIDAY AND SHOULD SET OFF SCATTERED SHOWERS AND A
FEW STORMS OVER MAINLY SOUTHEAST WYOMING FRIDAY AFTERNOON...
CONTINUING INTO THE EVENING BEFORE BECOMING MORE ISOLATED FRIDAY
NIGHT. A BIT COOLER TEMPS FRIDAY GIVEN MORE CLOUD COVER BUT STILL
WARM. A MORE SIGNIFICANT LOBE OF ENERGY LOOKS TO ROTATE NORTH
ACROSS THE AREA LATER SATURDAY WITH A DEEPER MOIST SE TO EASTERLY
FLOW SO MORE SIGNIFICANT PRECIPITATION A DISTINCT POSSIBILITY. A
FEW STORMS POSSIBLE OVER THE SOUTHERN CWA BUT BETTER SHEAR AND
INSTABILITY SHOULD STAY TO THE SOUTH.  WILL HAVE TO WATCH FOR
POTENTIALLY HEAVY RAINS ESPECIALLY CLOSER TO THE COLORADO BORDER
WITH SNOW LEVELS DROPPING TO AROUND 8-9KFT SATURDAY NIGHT. DECENT
SNOWFALL A POSSIBILITY OVER THE HIGHER MTNS SATURDAY NIGHT AS
WELL.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 340 PM MDT THU MAY 5 2016

THE UPPER LOW WILL REMAIN OVERHEAD ON SUNDAY ALONG WITH
PERSISTENT ALBEIT SOMEWHAT WEAKER UPSLOPE FLOW...BRINGING A
CONTINUED CHANCE FOR SHOWERS AND A FEW T-STORMS THROUGH THE DAY.
THIS UPPER LOW WILL SHIFT EAST FOR MONDAY...HOWEVER ANOTHER UPPER
SHORTWAVE DIVING SOUTHWEST FROM CANADA WILL BRING A RENEWED
CHANCE FOR SHOWERS AND AFTERNOON T-STORMS ON MONDAY. OVERALL
PRECIP TOTALS LOOK LESS WITH THIS SYSTEM DUE TO THE DISCONNECT
WITH GULF MOISTURE. TUE/WED WILL CONTINUE TO BE SHOWERY AS THIS
UPPER TROUGH SLOWLY MOVES EASTWARD ACROSS THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1205 PM MDT THU MAY 5 2016

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH A STEADY
STREAM OF HIGH CIRRUS MOVING OVERHEAD FROM THE SOUTHWEST. SOME
GUSTY WEST-SOUTHWEST WINDS ARE POSSIBLE AT TIMES THIS
AFTERNOON...WITH WINDS BECOMING SOUTHERLY AND GUSTY ACROSS THE
PANHANDLE TONIGHT. RAIN SHOWERS WITH A FEW T-STORMS WILL BEGIN TO
SPREAD FROM SOUTHWEST TO NORTHEAST FRIDAY LATE MORNING.

&&

.FIRE WEATHER...
ISSUED AT 340 PM MDT THU MAY 5 2016

NO CONCERNS SEEN THROUGH THE WEEKEND WITH COOLER AND WETTER
CONDITIONS RETURNING TO THE AREA.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS65 KCYS 052141
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
341 PM MDT THU MAY 5 2016

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM MDT THU MAY 5 2016

QUIET WEATHER WILL CONTINUE FOR ONE MORE NIGHT ACROSS THE CWA WITH
JUST SOME HIGH CLOUDINESS PASSING ACROSS THE REGION. UPPER RIDGE
AXIS CURRENTLY OVER THE HIGH PLAINS WILL MOVE SLOWLY EAST
OVERNIGHT LEAVING THE CWA UNDER AN INCREASINGLY MOIST SOUTHERLY
FLOW ALOFT AHEAD OF AN UPPER LOW THAT WILL MOVE INTO SOUTHERN
CALIFORNIA FRIDAY. AN INITIAL UPPER IMPULSE WILL LIFT NORTH ACROSS
THE AREA LATE FRIDAY AND SHOULD SET OFF SCATTERED SHOWERS AND A
FEW STORMS OVER MAINLY SOUTHEAST WYOMING FRIDAY AFTERNOON...
CONTINUING INTO THE EVENING BEFORE BECOMING MORE ISOLATED FRIDAY
NIGHT. A BIT COOLER TEMPS FRIDAY GIVEN MORE CLOUD COVER BUT STILL
WARM. A MORE SIGNIFICANT LOBE OF ENERGY LOOKS TO ROTATE NORTH
ACROSS THE AREA LATER SATURDAY WITH A DEEPER MOIST SE TO EASTERLY
FLOW SO MORE SIGNIFICANT PRECIPITATION A DISTINCT POSSIBILITY. A
FEW STORMS POSSIBLE OVER THE SOUTHERN CWA BUT BETTER SHEAR AND
INSTABILITY SHOULD STAY TO THE SOUTH.  WILL HAVE TO WATCH FOR
POTENTIALLY HEAVY RAINS ESPECIALLY CLOSER TO THE COLORADO BORDER
WITH SNOW LEVELS DROPPING TO AROUND 8-9KFT SATURDAY NIGHT. DECENT
SNOWFALL A POSSIBILITY OVER THE HIGHER MTNS SATURDAY NIGHT AS
WELL.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 340 PM MDT THU MAY 5 2016

THE UPPER LOW WILL REMAIN OVERHEAD ON SUNDAY ALONG WITH
PERSISTENT ALBEIT SOMEWHAT WEAKER UPSLOPE FLOW...BRINGING A
CONTINUED CHANCE FOR SHOWERS AND A FEW T-STORMS THROUGH THE DAY.
THIS UPPER LOW WILL SHIFT EAST FOR MONDAY...HOWEVER ANOTHER UPPER
SHORTWAVE DIVING SOUTHWEST FROM CANADA WILL BRING A RENEWED
CHANCE FOR SHOWERS AND AFTERNOON T-STORMS ON MONDAY. OVERALL
PRECIP TOTALS LOOK LESS WITH THIS SYSTEM DUE TO THE DISCONNECT
WITH GULF MOISTURE. TUE/WED WILL CONTINUE TO BE SHOWERY AS THIS
UPPER TROUGH SLOWLY MOVES EASTWARD ACROSS THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1205 PM MDT THU MAY 5 2016

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH A STEADY
STREAM OF HIGH CIRRUS MOVING OVERHEAD FROM THE SOUTHWEST. SOME
GUSTY WEST-SOUTHWEST WINDS ARE POSSIBLE AT TIMES THIS
AFTERNOON...WITH WINDS BECOMING SOUTHERLY AND GUSTY ACROSS THE
PANHANDLE TONIGHT. RAIN SHOWERS WITH A FEW T-STORMS WILL BEGIN TO
SPREAD FROM SOUTHWEST TO NORTHEAST FRIDAY LATE MORNING.

&&

.FIRE WEATHER...
ISSUED AT 340 PM MDT THU MAY 5 2016

NO CONCERNS SEEN THROUGH THE WEEKEND WITH COOLER AND WETTER
CONDITIONS RETURNING TO THE AREA.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS63 KUNR 052038
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
238 PM MDT THU MAY 5 2016

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 220 PM MDT THU MAY 5 2016

AFTN SFC ANALYSIS SHOWS SOUTHERLY WINDS HAVE DEVELOPED MUCH OF THE
REGION DUE TO THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
CENTRAL CONUS AND LOW PRESSURE EXTENDING FROM CENTRAL MANITOBA
ACROSS MONTANA AND THEN INTO THE FOUR CORNERS REGION. SUNNY SKIES
AND SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGE HAS HELPED TO PUSH
TEMPERATURES INTO THE UPPER 70S TO MID 80S OVER THE FORECAST AREA.
MODELS ARE SHOWING 500-1000J/KG CAPE OVER THE BLACK HILLS AND
PARTS OF THE WESTERN SOUTH DAKOTA PLAINS HOWEVER SUBSIDENCE AND
RELATIVELY WARM AIR ALOFT WILL KEEP ANY THUNDERSTORMS FROM
DEVELOPING THIS AFTN/EVE.

TONIGHT...A 35-45KT LOW LEVEL JET WILL DEVELOP FROM SOUTHWESTERN
INTO NORTHEASTERN SOUTH DAKOTA. THERE MAY BE SOME BREEZY
CONDITIONS OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS TONIGHT. THETA-E
ADVECTION WILL REMAIN RATHER WEAK HOWEVER SOME ACCAS MAY
FORM...BUT WITH RATHER DRY LOWER LEVELS EXPECT ONLY VIRGA TO
RESULT.

ON FRIDAY...THE UPPER RIDGE WILL MOVE OFF TO THE EAST AS A COLD
FRONT DROPS SOUTHWARD INTO THE FORECAST AREA. MOISTURE POOLING
ALONG BOUNDARY DURING PEAK HEATING...ESPECIALLY OVER SOUTHERN HALF
OF CWA...WILL RESULT IN 500- 1000J/KG MLCAPE AND WEAK 0-6KM BULK
SHEAR. MLCIN WEAK ENOUGH TO ALLOW TSRA TO DEVELOP IN THE AFTERNOON
AHEAD OF SHORTWAVE MOVING ACROSS CO INTO WY...WHICH IS AHEAD OF
UPPER LOW SPINNING OVER CA/NV. TEMPERATURES WILL BE TRICKY WITH
CLOUD COVER/PRECIPITATION COVERAGE AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

A LARGE UPPER LEVEL LOW LIFTS OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS
EASTWARD ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER
LOWS PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES BY MONDAY. THIS
WILL LEAD TO AN UNSETTLED AND WET WEATHER PATTERN...WITH DAILY
CHANCES FOR SHOWERS AND SOME ISOLATED THUNDERSTORMS. NEAR SEASONAL
TEMPERATURES ARE EXPECTED THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
A STRONG COLD FRONT WILL ENTER THE NORTHERN AND WESTERN PORTIONS OF
THE FORECAST AREA FRIDAY MORNING...WITH SURFACE WINDS SWITCHING TO
THE NORTH AND INCREASING TO 25 KTS.

&&

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

$$

SHORT TERM...10
LONG TERM...15
AVIATION...15




000
FXUS63 KUNR 052038
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
238 PM MDT THU MAY 5 2016

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 220 PM MDT THU MAY 5 2016

AFTN SFC ANALYSIS SHOWS SOUTHERLY WINDS HAVE DEVELOPED MUCH OF THE
REGION DUE TO THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
CENTRAL CONUS AND LOW PRESSURE EXTENDING FROM CENTRAL MANITOBA
ACROSS MONTANA AND THEN INTO THE FOUR CORNERS REGION. SUNNY SKIES
AND SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGE HAS HELPED TO PUSH
TEMPERATURES INTO THE UPPER 70S TO MID 80S OVER THE FORECAST AREA.
MODELS ARE SHOWING 500-1000J/KG CAPE OVER THE BLACK HILLS AND
PARTS OF THE WESTERN SOUTH DAKOTA PLAINS HOWEVER SUBSIDENCE AND
RELATIVELY WARM AIR ALOFT WILL KEEP ANY THUNDERSTORMS FROM
DEVELOPING THIS AFTN/EVE.

TONIGHT...A 35-45KT LOW LEVEL JET WILL DEVELOP FROM SOUTHWESTERN
INTO NORTHEASTERN SOUTH DAKOTA. THERE MAY BE SOME BREEZY
CONDITIONS OVER THE HIGHER ELEVATIONS OF THE BLACK HILLS TONIGHT. THETA-E
ADVECTION WILL REMAIN RATHER WEAK HOWEVER SOME ACCAS MAY
FORM...BUT WITH RATHER DRY LOWER LEVELS EXPECT ONLY VIRGA TO
RESULT.

ON FRIDAY...THE UPPER RIDGE WILL MOVE OFF TO THE EAST AS A COLD
FRONT DROPS SOUTHWARD INTO THE FORECAST AREA. MOISTURE POOLING
ALONG BOUNDARY DURING PEAK HEATING...ESPECIALLY OVER SOUTHERN HALF
OF CWA...WILL RESULT IN 500- 1000J/KG MLCAPE AND WEAK 0-6KM BULK
SHEAR. MLCIN WEAK ENOUGH TO ALLOW TSRA TO DEVELOP IN THE AFTERNOON
AHEAD OF SHORTWAVE MOVING ACROSS CO INTO WY...WHICH IS AHEAD OF
UPPER LOW SPINNING OVER CA/NV. TEMPERATURES WILL BE TRICKY WITH
CLOUD COVER/PRECIPITATION COVERAGE AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

A LARGE UPPER LEVEL LOW LIFTS OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS
EASTWARD ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER
LOWS PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES BY MONDAY. THIS
WILL LEAD TO AN UNSETTLED AND WET WEATHER PATTERN...WITH DAILY
CHANCES FOR SHOWERS AND SOME ISOLATED THUNDERSTORMS. NEAR SEASONAL
TEMPERATURES ARE EXPECTED THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY
ISSUED AT 220 PM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
A STRONG COLD FRONT WILL ENTER THE NORTHERN AND WESTERN PORTIONS OF
THE FORECAST AREA FRIDAY MORNING...WITH SURFACE WINDS SWITCHING TO
THE NORTH AND INCREASING TO 25 KTS.

&&

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

$$

SHORT TERM...10
LONG TERM...15
AVIATION...15




000
FXUS65 KRIW 051936
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
136 PM MDT THU MAY 5 2016

.SHORT TERM...TONIGHT THROUGH SUNDAY

HIGH CLOUDS HAVE ENCROACHED ON THE AREA TODAY. A HARBINGER OF THE
MAJOR CHANGE THAT IS TAKING SHAPE FOR FRIDAY THROUGH THE WEEKEND.
A FEW WEAK SHOWERS ARE STARTING TO FORM AND MAIN THREAT INTO EARLY
THIS EVENING WILL BE GUSTY WIND POTENTIAL WITH AREAS OF 40-50
DEGREE SPREADS IN THE SOUTHWEST. A FEW DYING GUSTY SHOWERS MAY
EDGE EAST OF THE DIVIDE INTO EARLY THIS EVENING. NOT MUCH LIQUID
BUT SOME BRIEF STRONG WIND GUSTS AND A LIGHTNING STRIKE OR TWO. FRIDAY
IS STILL SHAPING UP TO BE QUITE THE INTERESTING DAY. LARGE UPPER
LOW MOVES INTO SOCAL WHILE SRN CANADA SHORTWAVE PUSHES A COLD
FRONT SWD ACROSS THE AREA. UPPER LOW DYNAMICS START TO PUSH INTO
THE SOUTH WITH A RATHER COMPLEX JET INTERACTION. SWRN WYOMING WILL
SEE THE DAYTIME HEATING...APPROACHING FRONT...LARGE SCALE ASCENT
WITH UPPER LOW AND POSSIBLE UPPER JET SUPPORT. JET SUPPORT IS
QUITE INTERESTING AS FIRST JET STREAK MOVES UP AND STARTS TO
ROTATE WWD ACROSS SRN ID/NRN UT AREA WHILE MAIN CYCLONIC NOSE OF
THE JET NOSES INTO FAR NRN CO. THIS SETUP PUTS SWRN WYOMING IN
POTENTIAL STRONG UPPER DIVERGENCE. NORTH OF THE FRONT...WE CAN
STILL SEE SOME STRONGER STORMS WITH GOOD DIRECTIONAL SHEAR AND
MODERATE CAPE. MARGINAL RISK HAS BEEN MOVED TO INCLUDE CASPER AND
LANDER AND IS PRETTY MUCH WHERE WE`VE HAD IT FOR 3 DAYS NOW. AS
THE UPPER LOW MOVES SLOWLY NEWD FRIDAY NIGHT...WE SHOULD SEE
SIGNIFICANT LOWER ELEVATION RAIN AROUND PARTS OF SWRN AND MOST OF
CENTRAL WYOMING...CENTERED AROUND THE WIND RIVER BASIN/LANDER
FOOTHILLS AND SURROUNDING MOUNTAINS. FRONT PUSHES SOUTH FRIDAY
PROVIDING UPSLOPE WHILE MID LEVEL E-SE FLOW CONVEYOR BELT AND
ASSOCIATED LIFT... SATURATES THE ATMOSPHERE. MID LEVEL QG FORCING
AND UPPER JET SUPPORT FOR THE FIRST HALF OF THE EVENT ALL SPELLS
SIGNIFICANT PCPN. SNOW LEVELS LOOK MAYBE A TAD LOWER THAN
YESTERDAY. THINKING 9-9.5K IN THE WINDS AT 06Z SATURDAY WITH ABOUT
1K LOWER AT TIMES IN HEAVIER SHOWERS/TSTMS. 12Z SATURDAY MORNING
SNOW LEVELS WILL PROBABLY BE CLOSE TO 8500 FEET WITH SOME LOWERING
AT TIMES IN HEAVIER PCPN. THINKING LANDER WILL DROP INTO THE 41-44
DEGREE RANGE BY SATURDAY MORNING AND THEN THINKING ABOUT 3 DEGREES
COOLER PER 1K FEET. HIGHS IN LND WILL PROBABLY ONLY BE IN THE
46-48 RANGE WITH SNOW LEVELS 8.5K GENERALLY WITH SOME LOWERING IN
HEAVIER PCPN PERIODS. ANOTHER 500 FEET OR SO LOWER SATURDAY NIGHT
AS LOW GETS CLOSER. STILL LOOKING AT 1 TO 2 INCHES ACROSS THE WIND
RIVER BASIN WITH THE HIGHER AMOUNTS FROM AROUND RIVERTON WWD WITH
2.5-3 INCHES TOWARDS LANDER AND 3-4 IN THE WINDS AND POSSIBLY SRN
ABSAROKAS. HEAVY SNOW WILL FALL BUT MOSTLY ABOVE 10K INITIALLY AND
THEN GRADUALLY A LITTLE LOWER. 1-2 FEET OF SNOW WILL CERTAINLY
FALL UP HIGH BUT MOSTLY ABOVE ROAD LEVEL. OTHER SURROUNDING AREAS
WILL ALSO SEE THE POTENTIAL FOR .75 TO 1.5 INCHES OF RAIN FROM THE
SWRN AREAS TO CODY FOOTHILLS AND OVER TO NATRONA AND JOHNSON
COUNTY AND EVEN IN SWEETWATER COUNTY. THE LEAST WILL PROBABLY BE
THE FAR NWRN AREAS AND NR5N BIGHORN BASIN WHERE AMOUNTS WILL VARY
FROM A THIRD TO TWO-THIRDS IN GENERAL. STILL UNSETTLED SUNDAY WITH
UPPER LOW LIKELY TO BE WEAKENING AND MEANDERING JUST TO OUR SOUTH.
HARD TO FCST WHERE BANDS OF PCPN WILL BE BY THEN. THEY COULD BE
CLOSER AROUND THE LOW TO MAYBE SOME OUTER BANDS WILL COME INTO
PLAY. MOST AREAS WILL HAVE A CHANCE OF CONTINUED SHOWERS AND
HIGHER ELEVATION SNOW THROUGH THE END OF THIS PERIOD. BOTTOM
LINE...A MAJOR CHANGE FROM WARM AND DRY TO COOL/COLD AND WET (AND
WHITE UP HIGH) WITH A COUPLE (TO SEVERAL) INCHES OF LIQUID
CENTERED ON FREMONT COUNTY WITH LESS AS YOU FAN OUT FROM THERE.
HIGHS IN THE 70S AND 80S WILL STRUGGLE TO BE IN THE UPPER 40S TO
UPPER 50S ON FRIDAY FOR MANY LOWER ELEVATION AREAS.

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY

A SERIES OF LOW PRESSURE TROUGHS IN NORTH NORTHWEST FLOW WILL DIG
SOUTH SOUTHEAST FROM BRITISH COLUMBIA AND ALBERTA MOVING ACROSS
WESTERN MONTANA...EASTERN IDAHO AND WESTERN WYOMING BRINGING PERIODS
OF SHOWERS AND AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE
PERIOD.  TEMPERATURES WILL BE COOL AND MOST PERIODS TEMPERATURES ARE
COOLER THAN PREVIOUS FORECAST.  THE TREND IS FOR LESS PRECIPITATION
WEDNESDAY THROUGH THURSDAY BUT STILL SHOWERS AND THUNDERSTORMS WILL
BE MOVING THROUGH THE AREA WHILE BEING MOST NUMEROUS IN THE WESTERN
AND NORTHERN MOUNTAINS.

&&

.AVIATION.../00Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

VFR CONDITIONS ARE EXPECTED AT THE AIRPORTS THROUGH THE PERIOD.
AFTERNOON THUNDERSTORMS MAY PRODUCE BRIEF MVFR TO IFR CONDITIONS AT
ANY OF THE AIRPORTS.  SOUTHERLY FLOW ON THE EAST SIDE OF A DEEPENING
LOW PRESSURE CLOSED LOW WILL STREAM MOISTURE AND INSTABILITY NORTH
OVER THE WEST. AREAS OF MVFR CEILINGS WITH VISIBILITY REDUCED IN
RAIN AND SNOW SHOWERS AND FOG WILL INCREASE OVER THE MOUNTAINS ABOVE
8500 FEET THROUGH 00Z SATURDAY...BECOMING RATHER WIDESPREAD 10Z TO
13Z.  THUNDERSTORMS WITH HAIL...VERY HEAVY RAIN AND STRONG WIND
GUSTS ARE EXPECTED...STRONGEST ACROSS THE CENTRAL AND SOUTH FROM 19Z
TO 00Z.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

VFR CONDITIONS ARE EXPECTED AT THE AIRPORTS THROUGH THE PERIOD.
AFTERNOON THUNDERSTORMS MAY PRODUCE BRIEF MVFR TO IFR CONDITIONS AT
ANY OF THE AIRPORTS.  SOUTHERLY FLOW ON THE EAST SIDE OF A DEEPENING
LOW PRESSURE CLOSED LOW WILL STREAM MOISTURE AND INSTABILITY NORTH
OVER THE AREA.  AREAS OF MVFR CEILINGS WITH VISIBILITY REDUCED IN
RAIN AND SNOW SHOWERS AND FOG WILL INCREASE OVER THE MOUNTAINS ABOVE
8500 FEET THROUGH 00Z SATURDAY...BECOMING RATHER WIDESPREAD 12Z TO
14Z.  SURFACE WINDS WILL BE SOUTH TO SOUTHWEST UNTIL 12Z TO 15Z THEN
SHIFT TO THE EAST OR NORTHEAST AS THE LOW CIRCULATION DEEPENS
RAPIDLY EARLY FRIDAY MORNING. THUNDERSTORMS WITH HAIL...VERY HEAVY
RAIN AND STRONG WIND GUSTS ARE EXPECTED...STRONGEST ACROSS THE
CENTRAL AND SOUTH FROM 19ZTO 00Z.

&&

.FIRE WEATHER...

AN AREA OF LOW PRESSURE WILL MOVE TOWARD WYOMING OVER THE NEXT FEW
DAYS AND BRING INCREASINGLY COOL AND WET WEATHER. A FEW AFTERNOON
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE WESTERN MOUNTAINS THIS
AFTERNOON. MEANWHILE...AREAS EAST OF THE DIVIDE WILL SEE ONE MORE
WARM AND DRY DAY WITH A SOUTHWESTERLY BREEZE DEVELOPING. SOME AREAS
WILL HAVE RELATIVE HUMIDITY FALL INTO THE LOWER TEENS. WET WEATHER
WILL RETURN FRIDAY AND ESPECIALLY FRIDAY NIGHT INTO SATURDAY WITH A
WETTING RAIN LIKELY FOR MANY AREAS...ESPECIALLY EAST OF THE DIVIDE.


&&

.RIW WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY AFTERNOON FOR
WYZ017-018.

&&

$$

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




000
FXUS65 KCYS 051805
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1205 PM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1205 PM MDT THU MAY 5 2016

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH A STEADY
STREAM OF HIGH CIRRUS MOVING OVERHEAD FROM THE SOUTHWEST. SOME
GUSTY WEST-SOUTHWEST WINDS ARE POSSIBLE AT TIMES THIS
AFTERNOON...WITH WINDS BECOMING SOUTHERLY AND GUSTY ACROSS THE
PANHANDLE TONIGHT. RAIN SHOWERS WITH A FEW T-STORMS WILL BEGIN TO
SPREAD FROM SOUTHWEST TO NORTHEAST FRIDAY LATE MORNING.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS65 KCYS 051805
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1205 PM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1205 PM MDT THU MAY 5 2016

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH A STEADY
STREAM OF HIGH CIRRUS MOVING OVERHEAD FROM THE SOUTHWEST. SOME
GUSTY WEST-SOUTHWEST WINDS ARE POSSIBLE AT TIMES THIS
AFTERNOON...WITH WINDS BECOMING SOUTHERLY AND GUSTY ACROSS THE
PANHANDLE TONIGHT. RAIN SHOWERS WITH A FEW T-STORMS WILL BEGIN TO
SPREAD FROM SOUTHWEST TO NORTHEAST FRIDAY LATE MORNING.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS63 KUNR 051723
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1123 AM MDT THU MAY 5 2016

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

08Z SURFACE ANALYSIS HAD MODEST SOUTHERLY FLOW OVER THE CWA.
UPPER RIDGE SLOWLY MOVING EAST INTO THE PLAINS STATES WITH WARM
AIR ADVECTION CI SPILLING INTO THE CWA. UPPER TROUGH/LOW CURRENTLY
OFF THE CA COAST THE MAIN CONCERN THIS FORECAST PERIOD.

TODAY...UPPER/THERMAL RIDGE PEAKS OVER THE AREA WITH TEMPERATURES
WELL INTO THE 80S. 500J/KG MLCAPE WILL DEVELOP ON THE SD
PLAINS...BUT MLCIN WILL BE TOO STRONG WITH SUBSIDENCE ALOFT FOR TSRA.

TONIGHT...LOW LEVEL JET DEVELOPS OVER CENTRAL SD...BUT THETA-E
ADVECTION WEAK. PERHAPS SOME ACCAS WILL FORM...BUT PRECIPITATION
SHOULD BE PRECLUDED BY RATHER DRY SUB CLOUD LAYERS.

FRIDAY...UPPER RIDGE MOVES EAST AS COLD FRONT DROPS SOUTH INTO THE
CWA. MOISTURE POOLING ALONG BOUNDARY DURING PEAK
HEATING...ESPECIALLY OVER SOUTHERN HALF OF CWA...RESULTS IN 500-
1000J/KG MLCAPE AND WEAK 0-6KM BULK SHEAR. MLCIN WEAK ENOUGH TO
ALLOW TSRA TO DEVELOP IN THE AFTERNOON AHEAD OF SHORTWAVE MOVING
ACROSS CO INTO WY...WHICH IS AHEAD OF UPPER LOW SPINNING OVER CA/NV.
TEMPERATURES WILL BE TRICKY WITH CLOUD COVER/PRECIPITATION COVERAGE
AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 244 AM MDT THU MAY 5 2016

A STRONG UPPER LOW BEGINS TO MOVE OUT OF THE DESERT SOUTHWEST
INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS EASTWARD
ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER LOWS
PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES ON MONDAY. AFTER
THIS POINT THE MODELS BEGIN TO DISAGREE. THE ECMWF SEEMS TO
COMBINE THE TWO UPPER LOWS INTO ONE SYSTEM...THEN DEEPENS THE NEW
LOW AS IT SLOWLY MOVES ACROSS SOUTH DAKOTA WRAPPING PLENTY OF
MOISTURE AROUND IT. THE GFS SOLUTION PUSHES THE FIRST LOW INTO THE
GREAT LAKES REGION WHILE THE NEW LOW DEEPENS OVER THE FORECAST
AREA AND SLOWLY MOVES EAST ACROSS SOUTH DAKOTA. REGARDLESS OF THE
SOLUTION AND THE MODEL DIFFERENCES...BOTH MODELS INDICATE A WET
PATTERN WITH DAILY CHANCES FOR SHOWERS AND SEASONAL TEMPERATURES
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1121 AM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A STRONG
COLD FRONT WILL ENTER THE NORTHERN AND WESTERN PORTIONS OF THE
FORECAST AREA FRIDAY MORNING...WITH SURFACE WINDS SWITCHING TO THE
NORTH AND INCREASING TO 25 KTS.

&&

.FIRE WEATHER...
ISSUED AT 244 AM MDT THU MAY 5 2016

THIS AFTERNOON/S MINIMUM RELATIVE HUMIDITY WILL DROP TO THE MID
TEENS OVER NORTHEAST WY TO THE 20S OVER CENTRAL SD. SOUTHERLY WINDS
WILL AVERAGE 10 TO 20 MPH. FIRE WEATHER HEADLINES WILL NOT BE
NEEDED GIVEN THESE CONDITIONS.

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

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...15
FIRE WEATHER...HELGESON




000
FXUS65 KRIW 051650
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1050 AM MDT THU MAY 5 2016

.SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT

QUITE AN ACTIVE WEATHER PATTERN LOOKS TO BE SHAPING UP FOR THE NEXT
THREE DAYS. TODAY LOOKS TO BE THE LEAST ACTIVE DAY THOUGH. A SURGE
OF MID LEVEL MOISTURE AHEAD OF AN UPPER LEVEL AND SOME JET ENERGY
WILL BRING THE CHANCE OF A FEW SHOWERS AND THUNDERSTORMS WEST OF THE
DIVIDE THIS AFTERNOON AND EVENING. HOWEVER...MOST OF TODAY SHOULD BE
LARGELY RAIN FREE. MEANWHILE...EAST OF THE DIVIDE...THERE SHOULD BE
ONE MORE DRY DAY. THIS WILL BE THE WARMEST DAY...THE WARMEST FOR
MANY AREAS SO FAR THIS YEAR AS SOME SOUTHWESTERLY BREEZES BRING IN
SOME WARM AIR AHEAD OF THE UPPER LEVEL LOW. THERE WILL BE MANY HIGHS
IN THE 80S IN THE LOWER ELEVATIONS TODAY. AS FOR THE CHANCE OF
CONVECTION...A FEW SPOTS COULD SEE SOMETHING THIS EVENING...BUT MOST
AREAS SHOULD BE LARGELY DRY THROUGH TONIGHT.

THE MORE ACTIVE WEATHER STARTS TOMORROW. THE REGION WILL BE IN
SQUEEZE PLAY BETWEEN A COLD FRONT DROPPING DOWN FROM THE NORTH AND
AN UPPER LEVEL LOW THAT WILL PASS TO THE SOUTH OF WYOMING. THIS WILL
LIKELY PUMP COPIOUS AMOUNTS OF MOISTURE INTO THE AREA BEGINNING ON
FRIDAY. THERE IS ALSO THE CHANCE OF A FEW STRONGER THUNDERSTORMS.
THE STORM PREDICTION CENTER HAS A MARGINAL RISK ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE COUNTY WARNING AREA. THERE IS A DECENT
AMOUNT OF SHEAR IN THIS AREA SO A FEW STORMS COULD HAVE SOME HAIL
AND THE ALWAYS PRESENT STRONG WINDS IN WYOMING THUNDERSTORMS. THE
LIMITING FACTOR MAY BE SURFACE HEATING DUE TO CLOUD COVER HOWEVER.
FOR NOW...WE KEPT THE FORECAST FAIRLY CLOSE TO CONTINUITY.
HOWEVER...ALL AREAS WILL HAVE A CHANCE FOR THUNDERSTORMS.
TEMPERATURES WILL BE A CHALLENGE WITH THE GUIDANCE HAVING UP TO 12
DEGREES SPREADS FOR HIGH TEMPERATURES. WITH THE UNCERTAINTY...WE
KEPT THINGS FAIRLY SIMILAR OR JUST A BIT COOLER THAN CONTINUITY.

THE MAIN EVENT LOOKS TO BE FRIDAY NIGHT INTO SATURDAY IN THE FORM OF
A GOOD AMOUNT OF RAIN AS EAST TO EAST-NORTHEAST UPSLOPE FLOW
DEVELOPS. THIS WOULD PUT THE HEAVIEST RAIN OVER THE WIND RIVER BASIN
TO THE LANDER FOOTHILLS AND WIND RIVER RANGE AS WELL AS THE EAST
SLOPES OF THE ABSAROKAS AND THE BIG HORN RANGE. THE PREVIOUS
DISCUSSION MENTIONED UP 1 TO 2 INCHES IN THE LOWER ELEVATIONS AND WE
THINK THAT SEEMS FAIRLY REASONABLE. AT THIS TIME...THE HEAVIEST
PRECIPITATION LOOKS TO BE FRIDAY NIGHT INTO SATURDAY MORNING. WITH
SNOW LEVELS...STARTING OFF FAIRLY HIGH...OVER 10000 FEET...THIS
COULD BRING SOME RAPID SNOWMELT THAT COULD BRING SOME FLOODING
PROBLEMS. HOWEVER...WITH THE RECENT WARM WEATHER A DECENT AMOUNT OF
THE SNOW HAS MELTED AND THIS MAY MITIGATE THINGS JUST A BIT. IN
ADDITION...A COLD POOL MAY ROTATE OVER THE AREA AND LOWER SNOW
LEVELS DOWN TO AROUND 9000 FEET BY SATURDAY EVENING. THIS COULD ALSO
LIMIT SNOWMELT A BIT. THIS NEEDS TO BE WATCHED CLOSELY THOUGH. AS
FOR THE EFFECT OF THE SNOW...SOME AREAS WILL LIKELY SEE 1 TO 2 FEET
OF NEW SNOW. THESE WOULD BE WELL ABOVE PASS LEVEL MOST OF THE TIME
AND IMPACTS MAY BE MINIMAL EXCEPT FOR PEOPLE HEADING INTO THE
BACKCOUNTRY. IN ADDITION...ANY SNOW THAT FALLS ON PAVED SURFACES
DURING THE DAY WOULD LIKELY MELT WITH THE HIGH MAY SUN ANGLE. THE
STEADIEST PRECIPITATION MAY END BY SATURDAY EVENING AS THE BEST BEST
UPPER LEVEL SUPPORT MOVES AWAY TO THE EAST. THE PRECIPITATION WILL
NOT END...JUST BECOME LIGHTER. TEMPERATURES WILL ALSO BE A SHOCK TO
THE SYSTEM WITH SOME AREAS HAVING HIGHS AROUND 30 DEGREES COOLER FOR
HIGHS SATURDAY COMPARED TO THURSDAY.

.LONG TERM...SUNDAY THROUGH THURSDAY

THE MODELS DRIFT THIS WEATHER SYSTEM INTO EAST OR SOUTHEAST WY
SUNDAY AND MOVE IT INTO THE WESTERN HIGH PLAINS SUNDAY NIGHT.
THIS KEEPS RAIN SHOWERS IN THE FORECAST FOR MOST PLACES SUNDAY
INTO SUNDAY NIGHT ALONG AND EAST OF THE CONTINENTAL DIVIDE. AREAS
WEST OF THE DIVIDE WILL SEE SCATTERED SHOWERS SUNDAY INTO SUNDAY
EVENING. THE NEXT STORM SYSTEM DROPS INTO IDAHO MONDAY AFTERNOON
AND THEN ACROSS WY MONDAY NIGHT THROUGH TUESDAY. THE CURRENT TRACK
OF THIS SYSTEM WOULD PLACE THE HEAVIEST PRECIP OVER THE NORTH
HALF...SAY ALONG AND NORTH OF A CASPER TO JACKSON LINE MONDAY
NIGHT THROUGH TUESDAY WITH LESSER PRECIP OVER THE SOUTH HALF. THEN
TUESDAY NIGHT INTO WEDNESDAY THE STORM SYSTEM SLOWLY MOVES EAST
INTO THE HIGH PLAINS STATES. THE ECMWF IS SLOWER THAN THE GFS
WEDNESDAY AND THUS HAS MORE PRECIP EAST OF THE DIVIDE WED THAN THE
GFS. WEST OF THE DIVIDE...PRECIP WILL BE ON THE DECLINE TUESDAY
NIGHT AND WEDNESDAY. THE PRECIP DECREASES WED NIGHT EAST OF THE
DIVIDE AS THE SYSTEM MOVES OUT. NEXT THURSDAY LOOKS DRIER WITH
MAINLY ISOLATED SHOWERS OR STORMS. GFS MODEL HAS MORE COVERAGE
THAN THE ECMWF MODEL. WILL KEEP A LOW CHANCE FOR THE MOUNTAINS AND
ISOLATED FOR THE LOWER ELEVATIONS. TEMPS WILL BE NEAR TO BELOW
NORMAL DURING THE PERIOD.

&&

.AVIATION.../18Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

VFR CONDITIONS ARE EXPECTED AT THE AIRPORTS THROUGH THE PERIOD.
SOUTHERLY FLOW ON THE EAST SIDE OF A DEEPENING LOW PRESSURE CLOSED
LOW WILL STREAM MOISTURE AND INSTABILITY NORTH OVER THE WEST.
AREAS OF MVFR CEILINGS WITH VISIBILITY REDUCED IN RAIN AND SNOW
SHOWERS AND FOG WILL INCREASE OVER THE MOUNTAINS ABOVE 8500 FEET
THROUGH 18Z FRIDAY...BECOMING RATHER WIDESPREAD 10Z TO 13Z.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

VFR CONDITIONS ARE EXPECTED AT THE AIRPORTS THROUGH THE PERIOD.
SOUTHERLY FLOW ON THE EAST SIDE OF A DEEPENING LOW PRESSURE CLOSED
LOW WILL STREAM MOISTURE AND INSTABILITY NORTH OVER THE AREA.
AREAS OF MVFR CEILINGS WITH VISIBILITY REDUCED IN RAIN AND SNOW
SHOWERS AND FOG WILL INCREASE OVER THE MOUNTAINS ABOVE 8500 FEET
THROUGH 18Z FRIDAY...BECOMING RATHER WIDESPREAD 12Z TO 14Z.
SURFACE WINDS WILL BE SOUTH TO SOUTHWEST UNTIL 12Z TO 15Z THEN
SHIFT TO THE EAST OR NORTHEAST AS THE LOW CIRCULATION DEEPENS
RAPIDLY EARLY FRIDAY MORNING.

&&

.FIRE WEATHER...

AN AREA OF LOW PRESSURE WILL MOVE TOWARD WYOMING OVER THE NEXT FEW
DAYS AND BRING INCREASINGLY COOL AND WET WEATHER. A FEW AFTERNOON
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE WESTERN MOUNTAINS THIS
AFTERNOON. MEANWHILE...AREAS EAST OF THE DIVIDE WILL SEE ONE MORE
WARM AND DRY DAY WITH A SOUTHWESTERLY BREEZE DEVELOPING. SOME AREAS
WILL HAVE RELATIVE HUMIDITY FALL INTO THE LOWER TEENS. WET WEATHER
WILL RETURN FRIDAY AND ESPECIALLY FRIDAY NIGHT INTO SATURDAY WITH A
WETTING RAIN LIKELY FOR MANY AREAS...ESPECIALLY EAST OF THE
DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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




000
FXUS63 KUNR 051253
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
653 AM MDT THU MAY 5 2016

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

08Z SURFACE ANALYSIS HAD MODEST SOUTHERLY FLOW OVER THE CWA.
UPPER RIDGE SLOWLY MOVING EAST INTO THE PLAINS STATES WITH WARM
AIR ADVECTION CI SPILLING INTO THE CWA. UPPER TROUGH/LOW CURRENTLY
OFF THE CA COAST THE MAIN CONCERN THIS FORECAST PERIOD.

TODAY...UPPER/THERMAL RIDGE PEAKS OVER THE AREA WITH TEMPERATURES
WELL INTO THE 80S. 500J/KG MLCAPE WILL DEVELOP ON THE SD
PLAINS...BUT MLCIN WILL BE TOO STRONG WITH SUBSIDENCE ALOFT FOR TSRA.

TONIGHT...LOW LEVEL JET DEVELOPS OVER CENTRAL SD...BUT THETA-E
ADVECTION WEAK. PERHAPS SOME ACCAS WILL FORM...BUT PRECIPITATION
SHOULD BE PRECLUDED BY RATHER DRY SUB CLOUD LAYERS.

FRIDAY...UPPER RIDGE MOVES EAST AS COLD FRONT DROPS SOUTH INTO THE
CWA. MOISTURE POOLING ALONG BOUNDARY DURING PEAK
HEATING...ESPECIALLY OVER SOUTHERN HALF OF CWA...RESULTS IN 500-
1000J/KG MLCAPE AND WEAK 0-6KM BULK SHEAR. MLCIN WEAK ENOUGH TO
ALLOW TSRA TO DEVELOP IN THE AFTERNOON AHEAD OF SHORTWAVE MOVING
ACROSS CO INTO WY...WHICH IS AHEAD OF UPPER LOW SPINNING OVER CA/NV.
TEMPERATURES WILL BE TRICKY WITH CLOUD COVER/PRECIPITATION COVERAGE
AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 244 AM MDT THU MAY 5 2016

A STRONG UPPER LOW BEGINS TO MOVE OUT OF THE DESERT SOUTHWEST
INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS EASTWARD
ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER LOWS
PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES ON MONDAY. AFTER
THIS POINT THE MODELS BEGIN TO DISAGREE. THE ECMWF SEEMS TO
COMBINE THE TWO UPPER LOWS INTO ONE SYSTEM...THEN DEEPENS THE NEW
LOW AS IT SLOWLY MOVES ACROSS SOUTH DAKOTA WRAPPING PLENTY OF
MOISTURE AROUND IT. THE GFS SOLUTION PUSHES THE FIRST LOW INTO THE
GREAT LAKES REGION WHILE THE NEW LOW DEEPENS OVER THE FORECAST
AREA AND SLOWLY MOVES EAST ACROSS SOUTH DAKOTA. REGARDLESS OF THE
SOLUTION AND THE MODEL DIFFERENCES...BOTH MODELS INDICATE A WET
PATTERN WITH DAILY CHANCES FOR SHOWERS AND SEASONAL TEMPERATURES
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 653 AM MDT THU MAY 5 2016

FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 244 AM MDT THU MAY 5 2016

THIS AFTERNOON/S MINIMUM RELATIVE HUMIDITY WILL DROP TO THE MID
TEENS OVER NORTHEAST WY TO THE 20S OVER CENTRAL SD. SOUTHERLY WINDS
WILL AVERAGE 10 TO 20 MPH. FIRE WEATHER HEADLINES WILL NOT BE
NEEDED GIVEN THESE CONDITIONS.

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

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...MLS
FIRE WEATHER...HELGESON




000
FXUS63 KUNR 051253
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
653 AM MDT THU MAY 5 2016

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

08Z SURFACE ANALYSIS HAD MODEST SOUTHERLY FLOW OVER THE CWA.
UPPER RIDGE SLOWLY MOVING EAST INTO THE PLAINS STATES WITH WARM
AIR ADVECTION CI SPILLING INTO THE CWA. UPPER TROUGH/LOW CURRENTLY
OFF THE CA COAST THE MAIN CONCERN THIS FORECAST PERIOD.

TODAY...UPPER/THERMAL RIDGE PEAKS OVER THE AREA WITH TEMPERATURES
WELL INTO THE 80S. 500J/KG MLCAPE WILL DEVELOP ON THE SD
PLAINS...BUT MLCIN WILL BE TOO STRONG WITH SUBSIDENCE ALOFT FOR TSRA.

TONIGHT...LOW LEVEL JET DEVELOPS OVER CENTRAL SD...BUT THETA-E
ADVECTION WEAK. PERHAPS SOME ACCAS WILL FORM...BUT PRECIPITATION
SHOULD BE PRECLUDED BY RATHER DRY SUB CLOUD LAYERS.

FRIDAY...UPPER RIDGE MOVES EAST AS COLD FRONT DROPS SOUTH INTO THE
CWA. MOISTURE POOLING ALONG BOUNDARY DURING PEAK
HEATING...ESPECIALLY OVER SOUTHERN HALF OF CWA...RESULTS IN 500-
1000J/KG MLCAPE AND WEAK 0-6KM BULK SHEAR. MLCIN WEAK ENOUGH TO
ALLOW TSRA TO DEVELOP IN THE AFTERNOON AHEAD OF SHORTWAVE MOVING
ACROSS CO INTO WY...WHICH IS AHEAD OF UPPER LOW SPINNING OVER CA/NV.
TEMPERATURES WILL BE TRICKY WITH CLOUD COVER/PRECIPITATION COVERAGE
AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 244 AM MDT THU MAY 5 2016

A STRONG UPPER LOW BEGINS TO MOVE OUT OF THE DESERT SOUTHWEST
INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS EASTWARD
ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER LOWS
PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES ON MONDAY. AFTER
THIS POINT THE MODELS BEGIN TO DISAGREE. THE ECMWF SEEMS TO
COMBINE THE TWO UPPER LOWS INTO ONE SYSTEM...THEN DEEPENS THE NEW
LOW AS IT SLOWLY MOVES ACROSS SOUTH DAKOTA WRAPPING PLENTY OF
MOISTURE AROUND IT. THE GFS SOLUTION PUSHES THE FIRST LOW INTO THE
GREAT LAKES REGION WHILE THE NEW LOW DEEPENS OVER THE FORECAST
AREA AND SLOWLY MOVES EAST ACROSS SOUTH DAKOTA. REGARDLESS OF THE
SOLUTION AND THE MODEL DIFFERENCES...BOTH MODELS INDICATE A WET
PATTERN WITH DAILY CHANCES FOR SHOWERS AND SEASONAL TEMPERATURES
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 653 AM MDT THU MAY 5 2016

FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 244 AM MDT THU MAY 5 2016

THIS AFTERNOON/S MINIMUM RELATIVE HUMIDITY WILL DROP TO THE MID
TEENS OVER NORTHEAST WY TO THE 20S OVER CENTRAL SD. SOUTHERLY WINDS
WILL AVERAGE 10 TO 20 MPH. FIRE WEATHER HEADLINES WILL NOT BE
NEEDED GIVEN THESE CONDITIONS.

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

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...MLS
FIRE WEATHER...HELGESON




000
FXUS65 KCYS 051126
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
526 AM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 525 AM MDT THU MAY 5 2016

VFR CONDITIONS PREVAIL. SCT-TO-BKN COVERAGE OF CLOUDS ABOVE 20K FT
AGL THROUGH THE TAF PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS65 KCYS 051126
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
526 AM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 525 AM MDT THU MAY 5 2016

VFR CONDITIONS PREVAIL. SCT-TO-BKN COVERAGE OF CLOUDS ABOVE 20K FT
AGL THROUGH THE TAF PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS65 KRIW 050928
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
328 AM MDT THU MAY 5 2016

.SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT

QUITE AN ACTIVE WEATHER PATTERN LOOKS TO BE SHAPING UP FOR THE NEXT
THREE DAYS. TODAY LOOKS TO BE THE LEAST ACTIVE DAY THOUGH. A SURGE
OF MID LEVEL MOISTURE AHEAD OF AN UPPER LEVEL AND SOME JET ENERGY
WILL BRING THE CHANCE OF A FEW SHOWERS AND THUNDERSTORMS WEST OF THE
DIVIDE THIS AFTERNOON AND EVENING. HOWEVER...MOST OF TODAY SHOULD BE
LARGELY RAIN FREE. MEANWHILE...EAST OF THE DIVIDE...THERE SHOULD BE
ONE MORE DRY DAY. THIS WILL BE THE WARMEST DAY...THE WARMEST FOR
MANY AREAS SO FAR THIS YEAR AS SOME SOUTHWESTERLY BREEZES BRING IN
SOME WARM AIR AHEAD OF THE UPPER LEVEL LOW. THERE WILL BE MANY HIGHS
IN THE 80S IN THE LOWER ELEVATIONS TODAY. AS FOR THE CHANCE OF
CONVECTION...A FEW SPOTS COULD SEE SOMETHING THIS EVENING...BUT MOST
AREAS SHOULD BE LARGELY DRY THROUGH TONIGHT.

THE MORE ACTIVE WEATHER STARTS TOMORROW. THE REGION WILL BE IN
SQUEEZE PLAY BETWEEN A COLD FRONT DROPPING DOWN FROM THE NORTH AND
AN UPPER LEVEL LOW THAT WILL PASS TO THE SOUTH OF WYOMING. THIS WILL
LIKELY PUMP COPIOUS AMOUNTS OF MOISTURE INTO THE AREA BEGINNING ON
FRIDAY. THERE IS ALSO THE CHANCE OF A FEW STRONGER THUNDERSTORMS.
THE STORM PREDICTION CENTER HAS A MARGINAL RISK ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE COUNTY WARNING AREA. THERE IS A DECENT
AMOUNT OF SHEAR IN THIS AREA SO A FEW STORMS COULD HAVE SOME HAIL
AND THE ALWAYS PRESENT STRONG WINDS IN WYOMING THUNDERSTORMS. THE
LIMITING FACTOR MAY BE SURFACE HEATING DUE TO CLOUD COVER HOWEVER.
FOR NOW...WE KEPT THE FORECAST FAIRLY CLOSE TO CONTINUITY.
HOWEVER...ALL AREAS WILL HAVE A CHANCE FOR THUNDERSTORMS.
TEMPERATURES WILL BE A CHALLENGE WITH THE GUIDANCE HAVING UP TO 12
DEGREES SPREADS FOR HIGH TEMPERATURES. WITH THE UNCERTAINTY...WE
KEPT THINGS FAIRLY SIMILAR OR JUST A BIT COOLER THAN CONTINUITY.

THE MAIN EVENT LOOKS TO BE FRIDAY NIGHT INTO SATURDAY IN THE FORM OF
A GOOD AMOUNT OF RAIN AS EAST TO EAST-NORTHEAST UPSLOPE FLOW
DEVELOPS. THIS WOULD PUT THE HEAVIEST RAIN OVER THE WIND RIVER BASIN
TO THE LANDER FOOTHILLS AND WIND RIVER RANGE AS WELL AS THE EAST
SLOPES OF THE ABSAROKAS AND THE BIG HORN RANGE. THE PREVIOUS
DISCUSSION MENTIONED UP 1 TO 2 INCHES IN THE LOWER ELEVATIONS AND WE
THINK THAT SEEMS FAIRLY REASONABLE. AT THIS TIME...THE HEAVIEST
PRECIPITATION LOOKS TO BE FRIDAY NIGHT INTO SATURDAY MORNING. WITH
SNOW LEVELS...STARTING OFF FAIRLY HIGH...OVER 10000 FEET...THIS
COULD BRING SOME RAPID SNOWMELT THAT COULD BRING SOME FLOODING
PROBLEMS. HOWEVER...WITH THE RECENT WARM WEATHER A DECENT AMOUNT OF
THE SNOW HAS MELTED AND THIS MAY MITIGATE THINGS JUST A BIT. IN
ADDITION...A COLD POOL MAY ROTATE OVER THE AREA AND LOWER SNOW
LEVELS DOWN TO AROUND 9000 FEET BY SATURDAY EVENING. THIS COULD ALSO
LIMIT SNOWMELT A BIT. THIS NEEDS TO BE WATCHED CLOSELY THOUGH. AS
FOR THE EFFECT OF THE SNOW...SOME AREAS WILL LIKELY SEE 1 TO 2 FEET
OF NEW SNOW. THESE WOULD BE WELL ABOVE PASS LEVEL MOST OF THE TIME
AND IMPACTS MAY BE MINIMAL EXCEPT FOR PEOPLE HEADING INTO THE
BACKCOUNTRY. IN ADDITION...ANY SNOW THAT FALLS ON PAVED SURFACES
DURING THE DAY WOULD LIKELY MELT WITH THE HIGH MAY SUN ANGLE. THE
STEADIEST PRECIPITATION MAY END BY SATURDAY EVENING AS THE BEST BEST
UPPER LEVEL SUPPORT MOVES AWAY TO THE EAST. THE PRECIPITATION WILL
NOT END...JUST BECOME LIGHTER. TEMPERATURES WILL ALSO BE A SHOCK TO
THE SYSTEM WITH SOME AREAS HAVING HIGHS AROUND 30 DEGREES COOLER FOR
HIGHS SATURDAY COMPARED TO THURSDAY.

.LONG TERM...SUNDAY THROUGH THURSDAY

THE MODELS DRIFT THIS WEATHER SYSTEM INTO EAST OR SOUTHEAST WY
SUNDAY AND MOVE IT INTO THE WESTERN HIGH PLAINS SUNDAY NIGHT.
THIS KEEPS RAIN SHOWERS IN THE FORECAST FOR MOST PLACES SUNDAY
INTO SUNDAY NIGHT ALONG AND EAST OF THE CONTINENTAL DIVIDE. AREAS
WEST OF THE DIVIDE WILL SEE SCATTERED SHOWERS SUNDAY INTO SUNDAY
EVENING. THE NEXT STORM SYSTEM DROPS INTO IDAHO MONDAY AFTERNOON
AND THEN ACROSS WY MONDAY NIGHT THROUGH TUESDAY. THE CURRENT TRACK
OF THIS SYSTEM WOULD PLACE THE HEAVIEST PRECIP OVER THE NORTH
HALF...SAY ALONG AND NORTH OF A CASPER TO JACKSON LINE MONDAY
NIGHT THROUGH TUESDAY WITH LESSER PRECIP OVER THE SOUTH HALF. THEN
TUESDAY NIGHT INTO WEDNESDAY THE STORM SYSTEM SLOWLY MOVES EAST
INTO THE HIGH PLAINS STATES. THE ECMWF IS SLOWER THAN THE GFS
WEDNESDAY AND THUS HAS MORE PRECIP EAST OF THE DIVIDE WED THAN THE
GFS. WEST OF THE DIVIDE...PRECIP WILL BE ON THE DECLINE TUESDAY
NIGHT AND WEDNESDAY. THE PRECIP DECREASES WED NIGHT EAST OF THE
DIVIDE AS THE SYSTEM MOVES OUT. NEXT THURSDAY LOOKS DRIER WITH
MAINLY ISOLATED SHOWERS OR STORMS. GFS MODEL HAS MORE COVERAGE
THAN THE ECMWF MODEL. WILL KEEP A LOW CHANCE FOR THE MOUNTAINS AND
ISOLATED FOR THE LOWER ELEVATIONS. TEMPS WILL BE NEAR TO BELOW
NORMAL DURING THE PERIOD.

&&

.AVIATION.../12Z ISSUANCE/

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD WITH POSSIBLE
MVFR IF LOCAL SHOWERS IMPACT A TERMINAL. INCREASING SOUTH TO
SOUTHWEST FLOW AHEAD OF A WEATHER SYSTEM NEAR SOUTHERN CALIFORNIA
WILL SPREAD MID-LEVEL MOISTURE ACROSS WESTERN WYOMING TODAY.
ENOUGH MOISTURE WILL BE PRESENT TO GENERATE CONVECTION OVER THE HIGHER
TERRAIN AFTER 19Z. HAVE INCLUDED VCSH AT KJAC AND KBPI TO ACCOUNT FOR
CONVECTION MOVING OFF THE HIGHER TERRAIN THROUGH 02Z. POSSIBLE LIGHT
SHOWERS AFTER 02Z OVER FAR WEST WY. EXPECT SOUTH TO SOUTHWEST WIND TO
INCREASE BY EARLY AFTERNOON WITH THE WIND LOWERING BY 02Z IN MOST PLACES.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD. INCREASING
MOISTURE FROM THE SOUTH-SOUTHWEST WILL REACH CENTRAL WYOMING THIS
AFTERNOON. CONVECTION WILL GENERALLY BE CONFINED TO THE HIGHER
TERRAIN WITH VCSH ONLY NEEDED AT KCOD THIS AFTERNOON AND EVENING.
ONLY TERMINAL WITH WIND OF SIGNIFICANCE WILL BE KCPR...WHERE SPEEDS
OF 15 KTS GUSTING TO NEAR 25 KTS ARE ANTICIPATED FROM 16Z UNTIL 00Z.

&&

.FIRE WEATHER...

AN AREA OF LOW PRESSURE WILL MOVE TOWARD WYOMING OVER THE NEXT FEW
DAYS AND BRING INCREASINGLY COOL AND WET WEATHER. A FEW AFTERNOON
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE WESTERN MOUNTAINS THIS
AFTERNOON. MEANWHILE...AREAS EAST OF THE DIVIDE WILL SEE ONE MORE
WARM AND DRY DAY WITH A SOUTHWESTERLY BREEZE DEVELOPING. SOME AREAS
WILL HAVE RELATIVE HUMIDITY FALL INTO THE LOWER TEENS. WET WEATHER
WILL RETURN FRIDAY AND ESPECIALLY FRIDAY NIGHT INTO SATURDAY WITH A
WETTING RAIN LIKELY FOR MANY AREAS...ESPECIALLY EAST OF THE
DIVIDE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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




000
FXUS65 KCYS 050921
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
321 AM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1021 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS FROM 15Z TO 00Z ON THURSDAY.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...ZF
LONG TERM...CLH
AVIATION...RUBIN
FIRE WEATHER...ZF




000
FXUS65 KCYS 050921
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
321 AM MDT THU MAY 5 2016

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 258 AM MDT THU MAY 5 2016

ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS.  HIGHS WILL
BE A FEW DAYS WARMER THAN WEDNESDAY.  THE GFS SHOWS LI VALUES OF 0C
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER.  INSTABILITY IS
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST
WY.  THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.

LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW
CLOUDS TO THE EAST OF THE LARAMIE RANGE.  THE PERSISTENT UPSLOPE AND
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER.  THE MODELS
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO
INTO OUR CWA BY SATURDAY EVENING.  WIDESPREAD STRATIFORM RAIN WITH
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING
OVER THE SOUTHERN HALF OF THE CWA.  RAISED POPS INTO THE 70-80
PERCENT RANGE.  THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD
DEEP LAYER ASCENT.  WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA
MADRE AND SNOWY RANGES.  HOWEVER NOT EXPECTING SIGNIFICANT
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE
SATURDAY NIGHT.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 258 AM MDT THU MAY 5 2016

AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE
OF THE MOUNTAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1021 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS FROM 15Z TO 00Z ON THURSDAY.

&&

.FIRE WEATHER...
ISSUED AT 258 AM MDT THU MAY 5 2016

NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM HUMIDITY VALUES WILL
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY
AFTERNOON INTO SUNDAY MORNING.  TEMPERATURES WILL BE COOLER OVER THE
WEEKEND WITH INCREASING RELATIVE HUMIDITY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...ZF
LONG TERM...CLH
AVIATION...RUBIN
FIRE WEATHER...ZF




000
FXUS63 KUNR 050848
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
248 AM MDT THU MAY 5 2016

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

08Z SURFACE ANALYSIS HAD MODEST SOUTHERLY FLOW OVER THE CWA.
UPPER RIDGE SLOWLY MOVING EAST INTO THE PLAINS STATES WITH WARM
AIR ADVECTION CI SPILLING INTO THE CWA. UPPER TROUGH/LOW CURRENTLY
OFF THE CA COAST THE MAIN CONCERN THIS FORECAST PERIOD.

TODAY...UPPER/THERMAL RIDGE PEAKS OVER THE AREA WITH TEMPERATURES
WELL INTO THE 80S. 500J/KG MLCAPE WILL DEVELOP ON THE SD
PLAINS...BUT MLCIN WILL BE TOO STRONG WITH SUBSIDENCE ALOFT FOR TSRA.

TONIGHT...LOW LEVEL JET DEVELOPS OVER CENTRAL SD...BUT THETA-E
ADVECTION WEAK. PERHAPS SOME ACCAS WILL FORM...BUT PRECIPITATION
SHOULD BE PRECLUDED BY RATHER DRY SUB CLOUD LAYERS.

FRIDAY...UPPER RIDGE MOVES EAST AS COLD FRONT DROPS SOUTH INTO THE
CWA. MOISTURE POOLING ALONG BOUNDARY DURING PEAK
HEATING...ESPECIALLY OVER SOUTHERN HALF OF CWA...RESULTS IN 500-
1000J/KG MLCAPE AND WEAK 0-6KM BULK SHEAR. MLCIN WEAK ENOUGH TO
ALLOW TSRA TO DEVELOP IN THE AFTERNOON AHEAD OF SHORTWAVE MOVING
ACROSS CO INTO WY...WHICH IS AHEAD OF UPPER LOW SPINNING OVER CA/NV.
TEMPERATURES WILL BE TRICKY WITH CLOUD COVER/PRECIPITATION COVERAGE
AFFECTING EVENTUAL READINGS.

FRIDAY NIGHT...TSRA ACTIVITY QUIETS DOWN SOME WITH -SHRA BECOMING
MORE PREVALENT UNDER FAIRLY MOIST EAST/NORTHEAST BOUNDARY LAYER
FLOW. FORCING AHEAD OF UPPER LOW WILL BE FOCUSED OVER SOUTHWEST
THIRD OF CWA WHERE HIGHEST POPS WERE PAINTED. LOWS WILL BE NEAR
GUIDANCE.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 244 AM MDT THU MAY 5 2016

A STRONG UPPER LOW BEGINS TO MOVE OUT OF THE DESERT SOUTHWEST
INTO THE CENTRAL ROCKIES BY SUNDAY. THEN IT SLOWLY DRIFTS EASTWARD
ACROSS THE CENTRAL PLAINS ON MONDAY AND TUESDAY. ANOTHER LOWS
PUSHES SOUTHEASTWARD INTO THE NORTHERN ROCKIES ON MONDAY. AFTER
THIS POINT THE MODELS BEGIN TO DISAGREE. THE ECMWF SEEMS TO
COMBINE THE TWO UPPER LOWS INTO ONE SYSTEM...THEN DEEPENS THE NEW
LOW AS IT SLOWLY MOVES ACROSS SOUTH DAKOTA WRAPPING PLENTY OF
MOISTURE AROUND IT. THE GFS SOLUTION PUSHES THE FIRST LOW INTO THE
GREAT LAKES REGION WHILE THE NEW LOW DEEPENS OVER THE FORECAST
AREA AND SLOWLY MOVES EAST ACROSS SOUTH DAKOTA. REGARDLESS OF THE
SOLUTION AND THE MODEL DIFFERENCES...BOTH MODELS INDICATE A WET
PATTERN WITH DAILY CHANCES FOR SHOWERS AND SEASONAL TEMPERATURES
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT
ISSUED AT 244 AM MDT THU MAY 5 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 244 AM MDT THU MAY 5 2016

THIS AFTERNOON/S MINIMUM RELATIVE HUMIDITY WILL DROP TO THE MID
TEENS OVER NORTHEAST WY TO THE 20S OVER CENTRAL SD. SOUTHERLY WINDS
WILL AVERAGE 10 TO 20 MPH. FIRE WEATHER HEADLINES WILL NOT BE
NEEDED GIVEN THESE CONDITIONS.

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

$$

SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...MLS
FIRE WEATHER...HELGESON




000
FXUS65 KRIW 050430
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1030 PM MDT WED MAY 4 2016

.SHORT TERM AND LONG TERM...TONIGHT THROUGH NEXT WEDNESDAY

WARM RIDGE AXIS CENTERED OVER THE AREA WILL GRADUALLY SHIFT SLOWLY
EWD INTO THURSDAY AFTERNOON ALLOWING OUR UPPER LOW TO SLOWLY MOVE
TOWARD THE SOUTHERN CALIFORNIA COAST. THE MAJORITY OF THE GUIDANCE TAKE THIS
LARGE UPPER LOW INTO THE DESERT SW FRIDAY NIGHT INTO SATURDAY. AT
THE SAME TIME...A NRN PLAINS SHORTWAVE WILL PUSH A COOL FRONT SWD
QUICKLY DURING THE DAY FRIDAY. SETTING UP OUR CLASSIC PATTERN OF
UPSLOPE FOR AREAS ALONG AND EAST OF THE DIVIDE COMBINED WITH UPPER
DYNAMICS FROM THE LOW OVERRUNNING THIS COLD DOME. RAIN AMOUNTS
SHOULD BE SIGNIFICANT WITH RATHER HIGH SNOW LEVELS AT LEAST
INITIALLY...THEN GRADUALLY LOWERING LATER SATURDAY INTO SATURDAY
NIGHT. SNOW LEVELS WILL LIKELY START OUT FRIDAY EVENING NEAR 10K
FEET BUT WILL SLOWLY SLOWER INTO SATURDAY AFTERNOON. GFS IS COOLER
THAN THE NAM BY AT LEAST 500 TO 1000 FEET. WILL HAVE TO WATCH THIS
CLOSELY AS TO LOWER SNOW LEVELS WILL DEFINITELY HELP WITH THE
INITIAL AMOUNT OF RUNOFF OVER THE WEEKEND. THE MORE I LOOK AT
IT...THE MORE I LEAN TOWARDS THE LOWER SNOW LEVELS. SO INSTEAD OF
THE 9500 TO 10000 FEET SATURDAY MORNING THAT THE NAM12 WOULD GIVE
US...I`D LEAN TOWARDS THE 9000 FEET OR SO THAT THE GFS20 SHOWS.
SOMETHING TO WATCH. WHAT I DON`T LIKE IS THE MUCH DRIER GFS
THOUGH. STORM TOTALS ARE GENERALLY .75 TO 1 INCH ON THE GFS WHILE
THE 12Z ECMWF IS 4+ INCHES AROUND HERE AND AT LEAST 2-3 INCHES ON
THE GEM. LEAN TOWARDS A MIDDLE GROUND STILL WITH 1 TO 2 INCHES
ACROSS THE LOWER ELEVATIONS OF CENTRAL WY WITH CLOSER TO 2 IN THE
WRN HALF OF THE WIND RIVER BASIN AND ABOVE 2 CLOSER TO THE
FOOTHILLS FROM AROUND LANDER NORTHWESTWARD ALONG THE FOOTHILLS WITH 2 TO 4
INCHES ALONG THE EAST SLOPE OF THE WINDS WITH 2-3 INCHES IN THE
SRN ABSAROKAS.

MODELS STILL STRUGGLING WITH WHERE THE LOW WILL END UP BY SUNDAY
MORNING AND HOW FAST IT WILL MOVE EAST OF THE AREA. GFS IS ONCE
AGAIN SHOWING A PIECE OF THE LOW LIFTING NWD INTO SRN WY AND
STALLING OUT INTO MONDAY MORNING BEFORE JOINING THE REST OF THE LOW
OVER NEBRASKA LATER MONDAY. THE 12Z EURO LIFTS IT INTO FAR NRN
CO/EXTREME SRN WY SUNDAY MORNING AND THE SLOWLY MOVES IT OFF TO
WRN NE BY SUNDAY EVENING. A VERY WET SOLUTION FROM THE EURO WITH
OVER 4 INCHES ACROSS THE WIND RIVER BASIN VS THE INCH OR LESS ON
THE GFS. WILL STICK WITH MY INITIAL FEELING FROM THE PAST COUPLE
DAYS AS STATED IN THE FIRST PARAGRAPH. VARYING SOLUTIONS ALSO SHOW
UP WITH THE POTENTIAL SHORTWAVE DROPPING SEWD BEHIND OUR LARGE
UPPER LOW TUESDAY OR WEDNESDAY. ECMWF HAS BEEN PRETTY CONSISTENT
WITH THIS SYSTEM DROPPING SE ACROSS US TUESDAY. THE GFS IS
TRENDING THIS WAY BUT IS ABOUT A DAY SLOWER. WILL FOCUS ON OUR BIG
RAIN AND HIGHER SNOW EVENT OVER THE WEEKEND AND STICK WITH THE
GOING FCST FOR THIS NEXT EVENT. BOTTOM LINE...VERY WARM...DRY
WEATHER COMES TO A SCREECHING HALT LATER FRIDAY THROUGH THE
WEEKEND WITH SIGNIFICANT LOWER ELEVATION RAIN WITH THE PEAK AROUND
FREMONT COUNTY AND 1 TO 2 FEET OF SNOW ABOVE 10K FEET OR SO IN THE
WINDS. AHEAD OF THE UPPER LOW...WE SEE THE POTENTIAL FOR HIGHER
BASED GUSTY THUNDERSTORMS IN THE WEST THURSDAY AFTERNOON WITH
40-50 MPH WINDS VERY POSSIBLE WITH ISOLD SVR GUSTS NOT OUT OF THE
QUESTION. ON FRIDAY WITH THE FRONT COMING DOWN...THOSE AREAS IN
CENTRAL WYOMING START TO COOL WITH GRADUALLY INCREASING SHOWER
POTENTIAL FROM SW TO NE. SOUNDINGS STILL SHOWING STRONG TO SVR
TSTM POTENTIAL IN THE SWRN AND SRN AREAS INCLUDING
KJAC...KBPI...KRKS AND POSSIBLY AS FAR NORTH AS KLND/KRIW OVER TO
KCPR. THOSE LATTER AREAS ARE TURNING COOLER BUT STILL SHOW SOME
MODEST SHEAR AND DECENT CAPES. CAPES EVEN HIGHER FURTHER SOUTH IN
WARMER AIR. SHEAR NOT SHOWING QUITE AS STRONG AS YESTERDAY BUT
AVAILABLE CAPES OF 800-1200J/KG ARE LOOKING POSSIBLE. AFTER
THAT...MORE AND MORE RAIN WITH SOME EMBEDDED THUNDERSTORMS
POSSIBLE LATER FRIDAY NIGHT THROUGH SATURDAY NIGHT.

&&

.AVIATION.../06Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD WITH
POSSIBLE MVFR IF LOCAL SHOWERS IMPACT A TERMINAL. INCREASING
SOUTH-TO-SOUTHWEST FLOW AHEAD OF THE UPPER LOW APPROACHING THE
CALIFORNIA COAST WILL SPREAD MID-LEVEL MOISTURE ACROSS WESTERN
WYOMING THURSDAY. ENOUGH MOISTURE TO GENERATE CONVECTION OVER THE
HIGHER TERRAIN AFTER 19Z/THURSDAY. HAVE INCLUDED VCSH AT KJAC AND
KBPI TO ACCOUNT FOR CONVECTION MOVING OFF THE HIGHER TERRAIN...WITH
LOWERING CEILINGS AN POSSIBLE LIGHT OVERNIGHT SHOWERS PAST
02Z/FRIDAY. EXPECT SOUTH-SOUTHWEST WIND TO INCREASE BY EARLY THURSDAY
AFTERNOON WITH SPEEDS 9-15KTS. KRKS WINDS WILL BE ABOUT 5KTS HIGHER.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD...WITH
POSSIBLE MVFR CONDITIONS AT KCOD AFTER 02Z/FRIDAY IS LOCAL SHOWER
IMPACTS THE TERMINAL. LEADING EDGE OF INCREASING MOISTURE FROM THE
SOUTH-SOUTHWEST WILL REACH CENTRAL WYOMING BY EARLY THURSDAY
AFTERNOON. CONVECTION WILL GENERALLY BE CONFINED TO THE HIGHER
TERRAIN WITH VCSH ONLY NEEDED AT KCOD THURSDAY AFTERNOON AND EVENING.
ONLY TERMINAL WITH WIND OF SIGNIFICANCE WILL BE KCPR...WHERE
SOUTHWEST WIND AROUND 10KTS WILL HOLD STEADY OVERNIGHT. THIS
WIND WILL INCREASE AGAIN BETWEEN 14Z-16Z/THURSDAY WITH SPEEDS
14G20KTS ANTICIPATED. OTHER TERMINALS WILL SEE INCREASING SOUTH OR
EVEN SOUTHEAST FLOW DURING THE AFTERNOON WITH SPEEDS 6-10KTS.

&&

.FIRE WEATHER...

MAINLY DRY AND WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
MORNING FOR ALL AREAS. RELATIVE HUMIDITY WILL FALL INTO THE TEENS
FOR MANY LOWER ELEVATION LOCATIONS...BUT WINDS SHOULD REMAIN LIGHT
TO MODERATE. THE CHANCE OF SHOWERS WILL INCREASE IN THE WEST
THURSDAY AFTERNOON WITH A CHANCE OF THUNDERSTORMS FOR ALL AREAS ON
FRIDAY. A WETTING RAIN IS A GOOD POSSIBILITY FOR MANY AREAS FROM
FRIDAY NIGHT INTO THE WEEKEND. EXPECT MAINLY FAIR MIXING CONDITIONS
AND SMOKE DISPERSAL TODAY WITH FAIR TO GOOD SMOKE DISPERSAL THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...PS
LONG TERM...PS
AVIATION...MCDONALD
FIRE WEATHER...PS




000
FXUS65 KRIW 050430
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1030 PM MDT WED MAY 4 2016

.SHORT TERM AND LONG TERM...TONIGHT THROUGH NEXT WEDNESDAY

WARM RIDGE AXIS CENTERED OVER THE AREA WILL GRADUALLY SHIFT SLOWLY
EWD INTO THURSDAY AFTERNOON ALLOWING OUR UPPER LOW TO SLOWLY MOVE
TOWARD THE SOUTHERN CALIFORNIA COAST. THE MAJORITY OF THE GUIDANCE TAKE THIS
LARGE UPPER LOW INTO THE DESERT SW FRIDAY NIGHT INTO SATURDAY. AT
THE SAME TIME...A NRN PLAINS SHORTWAVE WILL PUSH A COOL FRONT SWD
QUICKLY DURING THE DAY FRIDAY. SETTING UP OUR CLASSIC PATTERN OF
UPSLOPE FOR AREAS ALONG AND EAST OF THE DIVIDE COMBINED WITH UPPER
DYNAMICS FROM THE LOW OVERRUNNING THIS COLD DOME. RAIN AMOUNTS
SHOULD BE SIGNIFICANT WITH RATHER HIGH SNOW LEVELS AT LEAST
INITIALLY...THEN GRADUALLY LOWERING LATER SATURDAY INTO SATURDAY
NIGHT. SNOW LEVELS WILL LIKELY START OUT FRIDAY EVENING NEAR 10K
FEET BUT WILL SLOWLY SLOWER INTO SATURDAY AFTERNOON. GFS IS COOLER
THAN THE NAM BY AT LEAST 500 TO 1000 FEET. WILL HAVE TO WATCH THIS
CLOSELY AS TO LOWER SNOW LEVELS WILL DEFINITELY HELP WITH THE
INITIAL AMOUNT OF RUNOFF OVER THE WEEKEND. THE MORE I LOOK AT
IT...THE MORE I LEAN TOWARDS THE LOWER SNOW LEVELS. SO INSTEAD OF
THE 9500 TO 10000 FEET SATURDAY MORNING THAT THE NAM12 WOULD GIVE
US...I`D LEAN TOWARDS THE 9000 FEET OR SO THAT THE GFS20 SHOWS.
SOMETHING TO WATCH. WHAT I DON`T LIKE IS THE MUCH DRIER GFS
THOUGH. STORM TOTALS ARE GENERALLY .75 TO 1 INCH ON THE GFS WHILE
THE 12Z ECMWF IS 4+ INCHES AROUND HERE AND AT LEAST 2-3 INCHES ON
THE GEM. LEAN TOWARDS A MIDDLE GROUND STILL WITH 1 TO 2 INCHES
ACROSS THE LOWER ELEVATIONS OF CENTRAL WY WITH CLOSER TO 2 IN THE
WRN HALF OF THE WIND RIVER BASIN AND ABOVE 2 CLOSER TO THE
FOOTHILLS FROM AROUND LANDER NORTHWESTWARD ALONG THE FOOTHILLS WITH 2 TO 4
INCHES ALONG THE EAST SLOPE OF THE WINDS WITH 2-3 INCHES IN THE
SRN ABSAROKAS.

MODELS STILL STRUGGLING WITH WHERE THE LOW WILL END UP BY SUNDAY
MORNING AND HOW FAST IT WILL MOVE EAST OF THE AREA. GFS IS ONCE
AGAIN SHOWING A PIECE OF THE LOW LIFTING NWD INTO SRN WY AND
STALLING OUT INTO MONDAY MORNING BEFORE JOINING THE REST OF THE LOW
OVER NEBRASKA LATER MONDAY. THE 12Z EURO LIFTS IT INTO FAR NRN
CO/EXTREME SRN WY SUNDAY MORNING AND THE SLOWLY MOVES IT OFF TO
WRN NE BY SUNDAY EVENING. A VERY WET SOLUTION FROM THE EURO WITH
OVER 4 INCHES ACROSS THE WIND RIVER BASIN VS THE INCH OR LESS ON
THE GFS. WILL STICK WITH MY INITIAL FEELING FROM THE PAST COUPLE
DAYS AS STATED IN THE FIRST PARAGRAPH. VARYING SOLUTIONS ALSO SHOW
UP WITH THE POTENTIAL SHORTWAVE DROPPING SEWD BEHIND OUR LARGE
UPPER LOW TUESDAY OR WEDNESDAY. ECMWF HAS BEEN PRETTY CONSISTENT
WITH THIS SYSTEM DROPPING SE ACROSS US TUESDAY. THE GFS IS
TRENDING THIS WAY BUT IS ABOUT A DAY SLOWER. WILL FOCUS ON OUR BIG
RAIN AND HIGHER SNOW EVENT OVER THE WEEKEND AND STICK WITH THE
GOING FCST FOR THIS NEXT EVENT. BOTTOM LINE...VERY WARM...DRY
WEATHER COMES TO A SCREECHING HALT LATER FRIDAY THROUGH THE
WEEKEND WITH SIGNIFICANT LOWER ELEVATION RAIN WITH THE PEAK AROUND
FREMONT COUNTY AND 1 TO 2 FEET OF SNOW ABOVE 10K FEET OR SO IN THE
WINDS. AHEAD OF THE UPPER LOW...WE SEE THE POTENTIAL FOR HIGHER
BASED GUSTY THUNDERSTORMS IN THE WEST THURSDAY AFTERNOON WITH
40-50 MPH WINDS VERY POSSIBLE WITH ISOLD SVR GUSTS NOT OUT OF THE
QUESTION. ON FRIDAY WITH THE FRONT COMING DOWN...THOSE AREAS IN
CENTRAL WYOMING START TO COOL WITH GRADUALLY INCREASING SHOWER
POTENTIAL FROM SW TO NE. SOUNDINGS STILL SHOWING STRONG TO SVR
TSTM POTENTIAL IN THE SWRN AND SRN AREAS INCLUDING
KJAC...KBPI...KRKS AND POSSIBLY AS FAR NORTH AS KLND/KRIW OVER TO
KCPR. THOSE LATTER AREAS ARE TURNING COOLER BUT STILL SHOW SOME
MODEST SHEAR AND DECENT CAPES. CAPES EVEN HIGHER FURTHER SOUTH IN
WARMER AIR. SHEAR NOT SHOWING QUITE AS STRONG AS YESTERDAY BUT
AVAILABLE CAPES OF 800-1200J/KG ARE LOOKING POSSIBLE. AFTER
THAT...MORE AND MORE RAIN WITH SOME EMBEDDED THUNDERSTORMS
POSSIBLE LATER FRIDAY NIGHT THROUGH SATURDAY NIGHT.

&&

.AVIATION.../06Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD WITH
POSSIBLE MVFR IF LOCAL SHOWERS IMPACT A TERMINAL. INCREASING
SOUTH-TO-SOUTHWEST FLOW AHEAD OF THE UPPER LOW APPROACHING THE
CALIFORNIA COAST WILL SPREAD MID-LEVEL MOISTURE ACROSS WESTERN
WYOMING THURSDAY. ENOUGH MOISTURE TO GENERATE CONVECTION OVER THE
HIGHER TERRAIN AFTER 19Z/THURSDAY. HAVE INCLUDED VCSH AT KJAC AND
KBPI TO ACCOUNT FOR CONVECTION MOVING OFF THE HIGHER TERRAIN...WITH
LOWERING CEILINGS AN POSSIBLE LIGHT OVERNIGHT SHOWERS PAST
02Z/FRIDAY. EXPECT SOUTH-SOUTHWEST WIND TO INCREASE BY EARLY THURSDAY
AFTERNOON WITH SPEEDS 9-15KTS. KRKS WINDS WILL BE ABOUT 5KTS HIGHER.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD...WITH
POSSIBLE MVFR CONDITIONS AT KCOD AFTER 02Z/FRIDAY IS LOCAL SHOWER
IMPACTS THE TERMINAL. LEADING EDGE OF INCREASING MOISTURE FROM THE
SOUTH-SOUTHWEST WILL REACH CENTRAL WYOMING BY EARLY THURSDAY
AFTERNOON. CONVECTION WILL GENERALLY BE CONFINED TO THE HIGHER
TERRAIN WITH VCSH ONLY NEEDED AT KCOD THURSDAY AFTERNOON AND EVENING.
ONLY TERMINAL WITH WIND OF SIGNIFICANCE WILL BE KCPR...WHERE
SOUTHWEST WIND AROUND 10KTS WILL HOLD STEADY OVERNIGHT. THIS
WIND WILL INCREASE AGAIN BETWEEN 14Z-16Z/THURSDAY WITH SPEEDS
14G20KTS ANTICIPATED. OTHER TERMINALS WILL SEE INCREASING SOUTH OR
EVEN SOUTHEAST FLOW DURING THE AFTERNOON WITH SPEEDS 6-10KTS.

&&

.FIRE WEATHER...

MAINLY DRY AND WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
MORNING FOR ALL AREAS. RELATIVE HUMIDITY WILL FALL INTO THE TEENS
FOR MANY LOWER ELEVATION LOCATIONS...BUT WINDS SHOULD REMAIN LIGHT
TO MODERATE. THE CHANCE OF SHOWERS WILL INCREASE IN THE WEST
THURSDAY AFTERNOON WITH A CHANCE OF THUNDERSTORMS FOR ALL AREAS ON
FRIDAY. A WETTING RAIN IS A GOOD POSSIBILITY FOR MANY AREAS FROM
FRIDAY NIGHT INTO THE WEEKEND. EXPECT MAINLY FAIR MIXING CONDITIONS
AND SMOKE DISPERSAL TODAY WITH FAIR TO GOOD SMOKE DISPERSAL THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...PS
LONG TERM...PS
AVIATION...MCDONALD
FIRE WEATHER...PS




000
FXUS65 KCYS 050422
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1022 PM MDT WED MAY 4 2016

.UPDATE...
ISSUED AT 944 PM MDT WED MAY 4 2016

FOR THE MID EVENING UPDATE NOT A WHOLE LOT TO CHANGE WITH THE
EXCEPTION OF MINOR TEMPERATURE TWEAKS FOR THE OVERNIGHT PERIOD AND
BRINGING IN SOME HIGH LEVEL CLOUDINESS A LITTLE EARLIER THAN
FORECASTED NEXT 24 HOURS BASED ON SATELLITE AND MODEL TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1021 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS FROM 15Z TO 00Z ON THURSDAY.

&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...JG
SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 050422
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1022 PM MDT WED MAY 4 2016

.UPDATE...
ISSUED AT 944 PM MDT WED MAY 4 2016

FOR THE MID EVENING UPDATE NOT A WHOLE LOT TO CHANGE WITH THE
EXCEPTION OF MINOR TEMPERATURE TWEAKS FOR THE OVERNIGHT PERIOD AND
BRINGING IN SOME HIGH LEVEL CLOUDINESS A LITTLE EARLIER THAN
FORECASTED NEXT 24 HOURS BASED ON SATELLITE AND MODEL TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1021 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS FROM 15Z TO 00Z ON THURSDAY.

&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...JG
SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS63 KUNR 050418
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1018 PM MDT WED MAY 4 2016

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 242 PM MDT WED MAY 4 2016

CURRENT SURFACE ANALYSIS SHOWS WARM FRONT MOVING INTO THE EASTERN
DAKOTAS...WITH WARM AIR IN PLACE ACROSS THE CWA. UPPER LEVEL
ANALYSIS SHOWS HIGH AMPLITUDE RIDGE OVER THE ROCKIES...MOVING
SLOWLY EAST ONTO THE PLAINS OVER THE NEXT 36 HRS. SKIES ARE MAINLY
SUNNY ACROSS THE AREA WITH TEMPS IN THE 70S. SOME BUILDING CUMULUS
HAS DEVELOPED OVER THE BLACK HILLS...BUT NO RADAR RETURNS AS OF
NOW. WINDS ARE MOSTLY ON THE LIGHTER SIDE FROM THE SOUTH TO
SOUTHEAST IN MOST AREAS.

OTHER THAN A STRAY SHOWER OR TWO OVER THE BLACK HILLS LATE THIS
AFTERNOON...DRY AND VERY WARM WEATHER IS EXPECTED THROUGH THE SHORT
TERM PERIOD. THERMAL RIDGE WILL SHIFT TO THE NORTHERN HIGH PLAINS
THURSDAY...WITH HIGHS IN THE 80S ACROSS MUCH OF THE CWA. WINDS WILL
BE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA...BECOME BREEZY AT
TIMES ACROSS PORTIONS OF SOUTHWEST INTO SOUTH CENTRAL SD LATER IN
THE DAY AND THURSDAY NIGHT AS LOW LEVEL JET DEVELOPS AND STRENGTHENS
OVER THE CENTRAL PLAINS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

UPPER RIDGE OVER THE CNTRL CONUS ON FRIDAY BEGINS TO BREAK DOWN
AS A STRONG UPPER LOW MOVES ONSHORE OVER SOUTHERN CALIFORNIA AND
ANOTHER LOW MOVES SOUTHEAST ACROSS SRN CANADA. MODELS AGREE ON A
SHORT-WAVE TROUGH MOVING OVER NERN WY AND SWRN SD FRIDAY
NIGHT...WHICH WILL RESULT IN A ROUND OF SHRA/TSRA. MUCAPE OF ONLY
500-1000J/KG AND 0-6KM BULK SHEAR VECTORS LESS THAN 25KT SUGGEST
ONLY PULSE SEVERE STORMS AT BEST. SLOW STORM MOTIONS MAY RESULT IN
LOCALLY HEAVY RAINFALL OVER NERN WY AND FAR SWRN SD.

THE SWRN CONUS UPPER LOW WILL MOVE OVER THE FOUR-CORNERS AREA BY
SUNDAY AND THEN DRIFT SLOWLY EASTWARD ACROSS THE CNTRL PLAINS MONDAY
AND TUESDAY. MODELS DISAGREE CONSIDERABLY AFTER 12Z MONDAY AS THE
ECMWF PARTIALLY ABSORBS THIS UPPER LOW INTO ANOTHER UPPER LOW COMING
FROM THE NORTHWEST...WHEREAS THE GFS EJECTS THE UPPER LOW EAST AHEAD
OF THE NEXT APPROACHING LOW. THE RESULT IS A BROAD-BRUSH OF POPS
OVER THE AREA THROUGH MOST OF THE EXTENDED PERIOD AS THE PATTERN IS
SOMEWHAT UNSETTLED. TEMPERATURES WILL BE WELL ABOVE AVERAGE FRIDAY
BUT THEN THEY WILL FALL BACK TO AROUND AVERAGE FOR THE REST OF THE
EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1017 PM MDT WED MAY 4 2016

VFR CONDITIONS THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...26
LONG TERM...BUNKERS
AVIATION...JC




000
FXUS63 KUNR 050418
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1018 PM MDT WED MAY 4 2016

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 242 PM MDT WED MAY 4 2016

CURRENT SURFACE ANALYSIS SHOWS WARM FRONT MOVING INTO THE EASTERN
DAKOTAS...WITH WARM AIR IN PLACE ACROSS THE CWA. UPPER LEVEL
ANALYSIS SHOWS HIGH AMPLITUDE RIDGE OVER THE ROCKIES...MOVING
SLOWLY EAST ONTO THE PLAINS OVER THE NEXT 36 HRS. SKIES ARE MAINLY
SUNNY ACROSS THE AREA WITH TEMPS IN THE 70S. SOME BUILDING CUMULUS
HAS DEVELOPED OVER THE BLACK HILLS...BUT NO RADAR RETURNS AS OF
NOW. WINDS ARE MOSTLY ON THE LIGHTER SIDE FROM THE SOUTH TO
SOUTHEAST IN MOST AREAS.

OTHER THAN A STRAY SHOWER OR TWO OVER THE BLACK HILLS LATE THIS
AFTERNOON...DRY AND VERY WARM WEATHER IS EXPECTED THROUGH THE SHORT
TERM PERIOD. THERMAL RIDGE WILL SHIFT TO THE NORTHERN HIGH PLAINS
THURSDAY...WITH HIGHS IN THE 80S ACROSS MUCH OF THE CWA. WINDS WILL
BE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA...BECOME BREEZY AT
TIMES ACROSS PORTIONS OF SOUTHWEST INTO SOUTH CENTRAL SD LATER IN
THE DAY AND THURSDAY NIGHT AS LOW LEVEL JET DEVELOPS AND STRENGTHENS
OVER THE CENTRAL PLAINS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

UPPER RIDGE OVER THE CNTRL CONUS ON FRIDAY BEGINS TO BREAK DOWN
AS A STRONG UPPER LOW MOVES ONSHORE OVER SOUTHERN CALIFORNIA AND
ANOTHER LOW MOVES SOUTHEAST ACROSS SRN CANADA. MODELS AGREE ON A
SHORT-WAVE TROUGH MOVING OVER NERN WY AND SWRN SD FRIDAY
NIGHT...WHICH WILL RESULT IN A ROUND OF SHRA/TSRA. MUCAPE OF ONLY
500-1000J/KG AND 0-6KM BULK SHEAR VECTORS LESS THAN 25KT SUGGEST
ONLY PULSE SEVERE STORMS AT BEST. SLOW STORM MOTIONS MAY RESULT IN
LOCALLY HEAVY RAINFALL OVER NERN WY AND FAR SWRN SD.

THE SWRN CONUS UPPER LOW WILL MOVE OVER THE FOUR-CORNERS AREA BY
SUNDAY AND THEN DRIFT SLOWLY EASTWARD ACROSS THE CNTRL PLAINS MONDAY
AND TUESDAY. MODELS DISAGREE CONSIDERABLY AFTER 12Z MONDAY AS THE
ECMWF PARTIALLY ABSORBS THIS UPPER LOW INTO ANOTHER UPPER LOW COMING
FROM THE NORTHWEST...WHEREAS THE GFS EJECTS THE UPPER LOW EAST AHEAD
OF THE NEXT APPROACHING LOW. THE RESULT IS A BROAD-BRUSH OF POPS
OVER THE AREA THROUGH MOST OF THE EXTENDED PERIOD AS THE PATTERN IS
SOMEWHAT UNSETTLED. TEMPERATURES WILL BE WELL ABOVE AVERAGE FRIDAY
BUT THEN THEY WILL FALL BACK TO AROUND AVERAGE FOR THE REST OF THE
EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1017 PM MDT WED MAY 4 2016

VFR CONDITIONS THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...26
LONG TERM...BUNKERS
AVIATION...JC




000
FXUS65 KCYS 050349 CCA
AFDCYS

AREA FORECAST DISCUSSION...CORRECTED UPDATE
NATIONAL WEATHER SERVICE CHEYENNE WY
944 PM MDT WED MAY 4 2016

.UPDATE...
ISSUED AT 944 PM MDT WED MAY 4 2016

FOR THE MID EVENING UPDATE NOT A WHOLE LOT TO CHANGE WITH THE
EXCEPTION OF MINOR TEMPERATURE TWEAKS FOR THE OVERNIGHT PERIOD AND
BRINGING IN SOME HIGH LEVEL CLOUDINESS A LITTLE EARLIER THAN
FORECASTED NEXT 24 HOURS BASED ON SATELLITE AND MODEL TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS AFTER 15Z THURSDAY.


&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...JG
SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 050344 AAA
AFDCYS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CHEYENNE WY
944 PM MDT WED MAY 4 2016

.UPDATE...
ISSUED AT 944 PM MDT WED MAY 4 2016

FOR THE MID EVENING UPDATE NOT A WHOLE LOT TO CHANGE WITH THE
EXCEPTION OF MINOR TEMPERATURE TWEAKS FOR THE OVERNIGHT PERIOD AND
BRINGING IN SOME HIGH LEVEL CLOUDINESS A LITTLER EARLIER THAN
FORECASTED NEXT 24 HOURS BASED ON SATELLITE AND MODEL TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS AFTER 15Z THURSDAY.


&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...JG
SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 050344 AAA
AFDCYS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CHEYENNE WY
944 PM MDT WED MAY 4 2016

.UPDATE...
ISSUED AT 944 PM MDT WED MAY 4 2016

FOR THE MID EVENING UPDATE NOT A WHOLE LOT TO CHANGE WITH THE
EXCEPTION OF MINOR TEMPERATURE TWEAKS FOR THE OVERNIGHT PERIOD AND
BRINGING IN SOME HIGH LEVEL CLOUDINESS A LITTLER EARLIER THAN
FORECASTED NEXT 24 HOURS BASED ON SATELLITE AND MODEL TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS AFTER 15Z THURSDAY.


&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...JG
SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS65 KCYS 042340
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
540 PM MDT WED MAY 4 2016

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERN TIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM MDT WED MAY 4 2016

VFR. GUSTS UP TO 25 KNOTS AFTER 15Z THURSDAY.

&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...RE
LONG TERM...RJM
AVIATION...RUBIN
FIRE WEATHER...RE




000
FXUS63 KUNR 042335
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
535 PM MDT WED MAY 4 2016

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 242 PM MDT WED MAY 4 2016

CURRENT SURFACE ANALYSIS SHOWS WARM FRONT MOVING INTO THE EASTERN
DAKOTAS...WITH WARM AIR IN PLACE ACROSS THE CWA. UPPER LEVEL
ANALYSIS SHOWS HIGH AMPLITUDE RIDGE OVER THE ROCKIES...MOVING
SLOWLY EAST ONTO THE PLAINS OVER THE NEXT 36 HRS. SKIES ARE MAINLY
SUNNY ACROSS THE AREA WITH TEMPS IN THE 70S. SOME BUILDING CUMULUS
HAS DEVELOPED OVER THE BLACK HILLS...BUT NO RADAR RETURNS AS OF
NOW. WINDS ARE MOSTLY ON THE LIGHTER SIDE FROM THE SOUTH TO
SOUTHEAST IN MOST AREAS.

OTHER THAN A STRAY SHOWER OR TWO OVER THE BLACK HILLS LATE THIS
AFTERNOON...DRY AND VERY WARM WEATHER IS EXPECTED THROUGH THE SHORT
TERM PERIOD. THERMAL RIDGE WILL SHIFT TO THE NORTHERN HIGH PLAINS
THURSDAY...WITH HIGHS IN THE 80S ACROSS MUCH OF THE CWA. WINDS WILL
BE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA...BECOME BREEZY AT
TIMES ACROSS PORTIONS OF SOUTHWEST INTO SOUTH CENTRAL SD LATER IN
THE DAY AND THURSDAY NIGHT AS LOW LEVEL JET DEVELOPS AND STRENGTHENS
OVER THE CENTRAL PLAINS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

UPPER RIDGE OVER THE CNTRL CONUS ON FRIDAY BEGINS TO BREAK DOWN
AS A STRONG UPPER LOW MOVES ONSHORE OVER SOUTHERN CALIFORNIA AND
ANOTHER LOW MOVES SOUTHEAST ACROSS SRN CANADA. MODELS AGREE ON A
SHORT-WAVE TROUGH MOVING OVER NERN WY AND SWRN SD FRIDAY
NIGHT...WHICH WILL RESULT IN A ROUND OF SHRA/TSRA. MUCAPE OF ONLY
500-1000J/KG AND 0-6KM BULK SHEAR VECTORS LESS THAN 25KT SUGGEST
ONLY PULSE SEVERE STORMS AT BEST. SLOW STORM MOTIONS MAY RESULT IN
LOCALLY HEAVY RAINFALL OVER NERN WY AND FAR SWRN SD.

THE SWRN CONUS UPPER LOW WILL MOVE OVER THE FOUR-CORNERS AREA BY
SUNDAY AND THEN DRIFT SLOWLY EASTWARD ACROSS THE CNTRL PLAINS MONDAY
AND TUESDAY. MODELS DISAGREE CONSIDERABLY AFTER 12Z MONDAY AS THE
ECMWF PARTIALLY ABSORBS THIS UPPER LOW INTO ANOTHER UPPER LOW COMING
FROM THE NORTHWEST...WHEREAS THE GFS EJECTS THE UPPER LOW EAST AHEAD
OF THE NEXT APPROACHING LOW. THE RESULT IS A BROAD-BRUSH OF POPS
OVER THE AREA THROUGH MOST OF THE EXTENDED PERIOD AS THE PATTERN IS
SOMEWHAT UNSETTLED. TEMPERATURES WILL BE WELL ABOVE AVERAGE FRIDAY
BUT THEN THEY WILL FALL BACK TO AROUND AVERAGE FOR THE REST OF THE
EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 534 PM MDT WED MAY 4 2016

VFR CONDITIONS THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...26
LONG TERM...BUNKERS
AVIATION...JC




000
FXUS63 KUNR 042335
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
535 PM MDT WED MAY 4 2016

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 242 PM MDT WED MAY 4 2016

CURRENT SURFACE ANALYSIS SHOWS WARM FRONT MOVING INTO THE EASTERN
DAKOTAS...WITH WARM AIR IN PLACE ACROSS THE CWA. UPPER LEVEL
ANALYSIS SHOWS HIGH AMPLITUDE RIDGE OVER THE ROCKIES...MOVING
SLOWLY EAST ONTO THE PLAINS OVER THE NEXT 36 HRS. SKIES ARE MAINLY
SUNNY ACROSS THE AREA WITH TEMPS IN THE 70S. SOME BUILDING CUMULUS
HAS DEVELOPED OVER THE BLACK HILLS...BUT NO RADAR RETURNS AS OF
NOW. WINDS ARE MOSTLY ON THE LIGHTER SIDE FROM THE SOUTH TO
SOUTHEAST IN MOST AREAS.

OTHER THAN A STRAY SHOWER OR TWO OVER THE BLACK HILLS LATE THIS
AFTERNOON...DRY AND VERY WARM WEATHER IS EXPECTED THROUGH THE SHORT
TERM PERIOD. THERMAL RIDGE WILL SHIFT TO THE NORTHERN HIGH PLAINS
THURSDAY...WITH HIGHS IN THE 80S ACROSS MUCH OF THE CWA. WINDS WILL
BE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA...BECOME BREEZY AT
TIMES ACROSS PORTIONS OF SOUTHWEST INTO SOUTH CENTRAL SD LATER IN
THE DAY AND THURSDAY NIGHT AS LOW LEVEL JET DEVELOPS AND STRENGTHENS
OVER THE CENTRAL PLAINS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

UPPER RIDGE OVER THE CNTRL CONUS ON FRIDAY BEGINS TO BREAK DOWN
AS A STRONG UPPER LOW MOVES ONSHORE OVER SOUTHERN CALIFORNIA AND
ANOTHER LOW MOVES SOUTHEAST ACROSS SRN CANADA. MODELS AGREE ON A
SHORT-WAVE TROUGH MOVING OVER NERN WY AND SWRN SD FRIDAY
NIGHT...WHICH WILL RESULT IN A ROUND OF SHRA/TSRA. MUCAPE OF ONLY
500-1000J/KG AND 0-6KM BULK SHEAR VECTORS LESS THAN 25KT SUGGEST
ONLY PULSE SEVERE STORMS AT BEST. SLOW STORM MOTIONS MAY RESULT IN
LOCALLY HEAVY RAINFALL OVER NERN WY AND FAR SWRN SD.

THE SWRN CONUS UPPER LOW WILL MOVE OVER THE FOUR-CORNERS AREA BY
SUNDAY AND THEN DRIFT SLOWLY EASTWARD ACROSS THE CNTRL PLAINS MONDAY
AND TUESDAY. MODELS DISAGREE CONSIDERABLY AFTER 12Z MONDAY AS THE
ECMWF PARTIALLY ABSORBS THIS UPPER LOW INTO ANOTHER UPPER LOW COMING
FROM THE NORTHWEST...WHEREAS THE GFS EJECTS THE UPPER LOW EAST AHEAD
OF THE NEXT APPROACHING LOW. THE RESULT IS A BROAD-BRUSH OF POPS
OVER THE AREA THROUGH MOST OF THE EXTENDED PERIOD AS THE PATTERN IS
SOMEWHAT UNSETTLED. TEMPERATURES WILL BE WELL ABOVE AVERAGE FRIDAY
BUT THEN THEY WILL FALL BACK TO AROUND AVERAGE FOR THE REST OF THE
EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 534 PM MDT WED MAY 4 2016

VFR CONDITIONS THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...26
LONG TERM...BUNKERS
AVIATION...JC




000
FXUS65 KCYS 042219
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
419 PM MDT WED MAY 4 2016

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERNTIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM MDT WED MAY 4 2016

VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL THROUGH THE PERIOD.
HOWEVER...COULD SEE OCCASIONAL GUSTS TO 20 KTS AT KRWL THIS
AFTERNOON...AND AT KCDR AFTER 05Z.

&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS65 KCYS 042219
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
419 PM MDT WED MAY 4 2016

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 419 PM MDT WED MAY 4 2016

QUIET WEATHER ACROSS THE CWA THIS AFTERNOON WILL CONTINUE THROUGH
THURSDAY AS AN UPPER RIDGE DRIFTS VERY SLOWLY EAST ACROSS THE
AREA. GENERALLY CLEAR SKIES ACROSS THE REGION TONIGHT AND THURSDAY
THEN A FEW SHOWERS MAY POP UP OVER THE HIGHER MOUNTAINS THURSDAY
AFTERNOON AS MOISTURE BEGINS TO INCREASE A BIT THERE DURING THE
DAY. WARM TEMPERATURES THURSDAY WITH MAXES IN THE MID 70S TO MID
80S OVER LOWER ELEVATIONS...ALONG WITH LIGHT WINDS. CHANGES BEGIN
ON FRIDAY AS THE UPPER RIDGE AXIS MOVES EAST AND LEAVES THE CWA
UNDER A SW TO SOUTHERLY UPPER FLOW AHEAD OF AN UPPER LOW TAT WILL
BE MOVING INTO THE FAR SW CONUS. INCREASING MOISTURE AND DIFFLUENT
UPPER FLOW WILL ALLOW FOR INCREASING SHOWERS AND A FEW STORMS
FRIDAY AFTERNOON AND NIGHT...AIDED BY AN INITIAL SHORTWAVE THAT
WILL LIFT NORTH ACROSS THE REGION AHEAD OF THE UPPER LOW. STILL
RELATIVELY WARM FRIDAY NIGHT SO ANY SNOW SHOULD BE CONFINED TO THE
HIGHEST PEAKS.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 419 PM MDT WED MAY 4 2016

THE UPPER LOW WILL STEADILY MOVE ACROSS THE 4 CORNERS REGION AND
ROCKIES SATURDAY THROUGH SUNDAY...THEN INTO THE CENTRAL PLAINS ON
MONDAY. SATURDAY MORNING COULD SEE A BRIEF LULL IN THE ACTION
ALTHOUGH PERSISTENT LLVL UPSLOPE FLOW WILL MAINTAIN LIGHT-
MODERATE RAIN IN UPSLOPE FAVORED LOCATIONS. MAY EVEN BE COLD
ENOUGH IN THE MORNING FOR A RAIN/SNOW MIX IN THE HIGH MOUNTAIN
PEAKS ABOVE 10KFT. AN EMBEDDED SHORTWAVE SWINGING UP FROM COLORADO
AND INTO THE CO/WY/NE REGION BY SATURDAY AFTERNOON WILL BRING A
RESURGENCE OF WIDESPREAD MODERATE TO LOCALLY HEAVY RAIN WHEN
COMBINED WITH CONTINUED UPSLOPE FLOW AND WEAK INSTABILITY. A FEW
T-STORMS ARE POSSIBLE AS WELL...BUT LOOK TO BE CONFINED MAINLY
WITHIN AND NEAR THE HIGHER TERRAIN AS THE PLAINS WILL BE TOO
STABLE. OVERALL RAIN RATES ON SATURDAY LOOK LOW WITH WEAK
INSTABILITY IN PLACE...BUT CANT RULE OUT A FEW STRONGER STORMS
MOVING UP FROM COLORADO MAINLY IN THE AFTERNOON/EVENING ACROSS THE
SOUTHERNTIER OF COUNTIES. STILL THINKING SNOW LEVELS WILL DROP
TO ROUGHLY 8-9KFT FEET BY SATURDAY NIGHT...WITH A FEW INCHES OF
SNOW ACCUMULATION POSSIBLE IN THE HIGHER PEAKS THROUGH SUNDAY.
WITH WATER LEVELS ALREADY SOMEWHAT HIGH ON THE LARAMIE AND LOWER
NORTH PLATTE RIVERS...COULD SEE PROBLEMS WITH MINOR FLOODING ALONG
THESE RIVERS DUE TO THE POTENTIAL RAINFALL OF AN INCH OR MORE
THROUGH SUNDAY. THINK THE UPPER NORTH PLATTE WILL SEE WATER RISES
AS WELL...BUT MAY NOT BE AS MUCH OF AN ISSUE SINCE CURRENT LEVELS
ARE RELATIVELY LOW. WILL CERTAINLY KEEP A CLOSE EYE ON THIS
SITUATION AS THE WEEKEND APPROACHES. WRAPAROUND MOISTURE AND
COLDER TEMPS ALOFT WILL MAINTAIN AT LEAST A CHANCE FOR SHOWERS AND
T-STORMS FOR MONDAY. TUESDAY LOOKS DRIER OVERALL AND A FEW DEGREES
WARMER AS THE UPPER LOW CONTINUES TO MOVE EASTWARD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM MDT WED MAY 4 2016

VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL THROUGH THE PERIOD.
HOWEVER...COULD SEE OCCASIONAL GUSTS TO 20 KTS AT KRWL THIS
AFTERNOON...AND AT KCDR AFTER 05Z.

&&

.FIRE WEATHER...
ISSUED AT 419 PM MDT WED MAY 4 2016

NO CONCERNS ANTICIPATED FOR THE REST OF THE WEEK INTO THE WEEKEND.
WARM TEMPERATURES WILL CONTINUE THURSDAY THEN COOLER AND WETTER
CONDITIONS WILL BEGIN BY LATE FRIDAY AND CONTINUE THROUGH THE
WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

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




000
FXUS63 KUNR 042043
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
243 PM MDT WED MAY 4 2016

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 242 PM MDT WED MAY 4 2016

CURRENT SURFACE ANALYSIS SHOWS WARM FRONT MOVING INTO THE EASTERN
DAKOTAS...WITH WARM AIR IN PLACE ACROSS THE CWA. UPPER LEVEL
ANALYSIS SHOWS HIGH AMPLITUDE RIDGE OVER THE ROCKIES...MOVING
SLOWLY EAST ONTO THE PLAINS OVER THE NEXT 36 HRS. SKIES ARE MAINLY
SUNNY ACROSS THE AREA WITH TEMPS IN THE 70S. SOME BUILDING CUMULUS
HAS DEVELOPED OVER THE BLACK HILLS...BUT NO RADAR RETURNS AS OF
NOW. WINDS ARE MOSTLY ON THE LIGHTER SIDE FROM THE SOUTH TO
SOUTHEAST IN MOST AREAS.

OTHER THAN A STRAY SHOWER OR TWO OVER THE BLACK HILLS LATE THIS
AFTERNOON...DRY AND VERY WARM WEATHER IS EXPECTED THROUGH THE SHORT
TERM PERIOD. THERMAL RIDGE WILL SHIFT TO THE NORTHERN HIGH PLAINS
THURSDAY...WITH HIGHS IN THE 80S ACROSS MUCH OF THE CWA. WINDS WILL
BE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA...BECOME BREEZY AT
TIMES ACROSS PORTIONS OF SOUTHWEST INTO SOUTH CENTRAL SD LATER IN
THE DAY AND THURSDAY NIGHT AS LOW LEVEL JET DEVELOPS AND STRENGTHENS
OVER THE CENTRAL PLAINS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

UPPER RIDGE OVER THE CNTRL CONUS ON FRIDAY BEGINS TO BREAK DOWN
AS A STRONG UPPER LOW MOVES ONSHORE OVER SOUTHERN CALIFORNIA AND
ANOTHER LOW MOVES SOUTHEAST ACROSS SRN CANADA. MODELS AGREE ON A
SHORT-WAVE TROUGH MOVING OVER NERN WY AND SWRN SD FRIDAY
NIGHT...WHICH WILL RESULT IN A ROUND OF SHRA/TSRA. MUCAPE OF ONLY
500-1000J/KG AND 0-6KM BULK SHEAR VECTORS LESS THAN 25KT SUGGEST
ONLY PULSE SEVERE STORMS AT BEST. SLOW STORM MOTIONS MAY RESULT IN
LOCALLY HEAVY RAINFALL OVER NERN WY AND FAR SWRN SD.

THE SWRN CONUS UPPER LOW WILL MOVE OVER THE FOUR-CORNERS AREA BY
SUNDAY AND THEN DRIFT SLOWLY EASTWARD ACROSS THE CNTRL PLAINS MONDAY
AND TUESDAY. MODELS DISAGREE CONSIDERABLY AFTER 12Z MONDAY AS THE
ECMWF PARTIALLY ABSORBS THIS UPPER LOW INTO ANOTHER UPPER LOW COMING
FROM THE NORTHWEST...WHEREAS THE GFS EJECTS THE UPPER LOW EAST AHEAD
OF THE NEXT APPROACHING LOW. THE RESULT IS A BROAD-BRUSH OF POPS
OVER THE AREA THROUGH MOST OF THE EXTENDED PERIOD AS THE PATTERN IS
SOMEWHAT UNSETTLED. TEMPERATURES WILL BE WELL ABOVE AVERAGE FRIDAY
BUT THEN THEY WILL FALL BACK TO AROUND AVERAGE FOR THE REST OF THE
EXTENDED PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 242 PM MDT WED MAY 4 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...26
LONG TERM...BUNKERS
AVIATION...BUNKERS




000
FXUS65 KRIW 041937
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
137 PM MDT WED MAY 4 2016

.SHORT TERM AND LONG TERM...TONIGHT THROUGH NEXT WEDNESDAY

WARM RIDGE AXIS CENTERED OVER THE AREA WILL GRADUALLY SHIFT SLOWLY
EWD INTO THURSDAY AFTERNOON ALLOWING OUR UPPER LOW TO SLOWLY MOVE
TOWARD THE SOCAL COAST. THE MAJORITY OF THE GUIDANCE TAKE THIS
LARGE UPPER LOW INTO THE DESERT SW FRIDAY NIGHT INTO SATURDAY. AT
THE SAME TIME...A NRN PLAINS SHORTWAVE WILL PUSH A COOL FRONT SWD
QUICKLY DURING THE DAY FRIDAY. SETTING UP OUR CLASSIC PATTERN OF
UPSLOPE FOR AREAS ALONG AND EAST OF THE DIVIDE COMBINED WITH UPPER
DYNAMICS FROM THE LOW OVERRUNNING THIS COLD DOME. RAIN AMOUNTS
SHOULD BE SIGNIFICANT WITH RATHER HIGH SNOW LEVELS AT LEAST
INITIALLY...THEN GRADUALLY LOWERING LATER SATURDAY INTO SATURDAY
NIGHT. SNOW LEVELS WILL LIKELY START OUT FRIDAY EVENING NEAR 10K
FEET BUT WILL SLOWLY SLOWER INTO SATURDAY AFTERNOON. GFS IS COOLER
THAN THE NAM BY AT LEAST 500 TO 1000 FEET. WILL HAVE TO WATCH THIS
CLOSELY AS TO LOWER SNOW LEVELS WILL DEFINITELY HELP WITH THE
INITIAL AMOUNT OF RUNOFF OVER THE WEEKEND. THE MORE I LOOK AT
IT...THE MORE I LEAN TOWARDS THE LOWER SNOW LEVELS. SO INSTEAD OF
THE 9500 TO 10000 FEET SATURDAY MORNING THAT THE NAM12 WOULD GIVE
US...I`D LEAN TOWARDS THE 9000 FEET OR SO THAT THE GFS20 SHOWS.
SOMETHING TO WATCH. WHAT I DON`T LIKE IS THE MUCH DRIER GFS
THOUGH. STORM TOTALS ARE GENERALLY .75 TO 1 INCH ON THE GFS WHILE
THE 12Z ECMWF IS 4+ INCHES AROUND HERE AND AT LEAST 2-3 INCHES ON
THE GEM. LEAN TOWARDS A MIDDLE GROUND STILL WITH 1 TO 2 INCHES
ACROSS THE LOWER ELEVATIONS OF CENTRAL WYO WITH CLOSER TO 2 IN THE
WRN HALF OF THE WIND RIVER BASIN AND ABOVE 2 CLOSER TO THE
FOOTHILLS FROM AROUND LANDER NWWD ALONG THE FOOTHILLS WITH 2 TO 4
INCHES ALONG THE EAST SLOPE OF THE WINDS WITH 2-3 INCHES IN THE
SRN ABSAROKAS.

MODELS STILL STRUGGLING WITH WHERE THE LOW WILL END UP BY SUNDAY
MORNING AND HOW FAST IT WILL MOVE EAST OF THE AREA. GFS IS ONCE
AGAIN SHOWING A PIECE OF THE LOW LIFTING NWD INTO SRN WYO AND
STALLING OUT INTO MONDAY MORNING BEFORE JOINING THE REST OF THE LOW
OVER NEBRASKA LATER MONDAY. THE 12Z EURO LIFTS IT INTO FAR NRN
CO/EXTREME SRN WY SUNDAY MORNING AND THE SLOWLY MOVES IT OFF TO
WRN NE BY SUNDAY EVENING. A VERY WET SOLUTION FROM THE EURO WITH
OVER 4 INCHES ACROSS THE WIND RIVER BASIN VS THE INCH OR LESS ON
THE GFS. WILL STICK WITH MY INITIAL FEELING FROM THE PAST COUPLE
DAYS AS STATED IN THE FIRST PARAGRAPH. VARYING SOLUTIONS ALSO SHOW
UP WITH THE POTENTIAL SHORTWAVE DROPPING SEWD BEHIND OUR LARGE
UPPER LOW TUESDAY OR WEDNESDAY. ECMWF HAS BEEN PRETTY CONSISTENT
WITH THIS SYSTEM DROPPING SE ACROSS US TUESDAY. THE GFS IS
TRENDING THIS WAY BUT IS ABOUT A DAY SLOWER. WILL FOCUS ON OUR BIG
RAIN AND HIGHER SNOW EVENT OVER THE WEEKEND AND STICK WITH THE
GOING FCST FOR THIS NEXT EVENT. BOTTOM LINE...VERY WARM...DRY
WEATHER COMES TO A SCREECHING HALT LATER FRIDAY THROUGH THE
WEEKEND WITH SIGNIFICANT LOWER ELEVATION RAIN WITH THE PEAK AROUND
FREMONT COUNTY AND 1 TO 2 FEET OF SNOW ABOVE 10K FEET OR SO IN THE
WINDS. AHEAD OF THE UPPER LOW...WE SEE THE POTENTIAL FOR HIGHER
BASED GUSTY THUNDERSTORMS IN THE WEST THURSDAY AFTERNOON WITH
40-50 MPH WINDS VERY POSSIBLE WITH ISOLD SVR GUSTS NOT OUT OF THE
QUESTION. ON FRIDAY WITH THE FRONT COMING DOWN...THOSE AREAS IN
CENTRAL WYOMING START TO COOL WITH GRADUALLY INCREASING SHOWER
POTENTIAL FROM SW TO NE. SOUNDINGS STILL SHOWING STRONG TO SVR
TSTM POTENTIAL IN THE SWRN AND SRN AREAS INCLUDING
KJAC...KBPI...KRKS AND POSSIBLY AS FAR NORTH AS KLND/KRIW OVER TO
KCPR. THOSE LATTER AREAS ARE TURNING COOLER BUT STILL SHOW SOME
MODEST SHEAR AND DECENT CAPES. CAPES EVEN HIGHER FURTHER SOUTH IN
WARMER AIR. SHEAR NOT SHOWING QUITE AS STRONG AS YESTERDAY BUT
AVAILABLE CAPES OF 800-1200J/KG ARE LOOKING POSSIBLE. AFTER
THAT...MORE AND MORE RAIN WITH SOME EMBEDDED THUNDERSTORMS
POSSIBLE LATER FRIDAY NIGHT THROUGH SATURDAY NIGHT.

&&

.AVIATION.../00Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD. INCREASING
SOUTH-TO-SOUTHWEST FLOW AHEAD OF THE UPPER LOW APPROACHING THE
CALIFORNIA COAST WILL SPREAD MID-LEVEL MOISTURE ACROSS WESTERN
WYOMING THURSDAY. ENOUGH MOISTURE TO GENERATE CONVECTION OVER THE
HIGHER TERRAIN AFTER 19Z/THURSDAY. HAVE INCLUDED VCSH AT KJAC AND
KBPI TO ACCOUNT FOR CONVECTION MOVING OFF THE HIGHER TERRAIN. EXPECT
SOUTH-SOUTHWEST WIND TO INCREASE BY EARLY THURSDAY AFTERNOON WITH
SPEEDS 9-15KTS. KRKS WINDS WILL BE ABOUT 5KTS HIGHER.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONDITIONS WILL REMAIN VFR THROUGH THE FORECAST PERIOD. LEADING
EDGE OF INCREASING MOISTURE FROM THE SOUTH-SOUTHWEST WILL REACH
CENTRAL WYOMING BY THURSDAY AFTERNOON. CONVECTION WILL GENERALLY
BE CONFINED TO THE HIGHER TERRAIN WITH VCSH ONLY NEEDED AT KCOD
THURSDAY AFTERNOON. ONLY TERMINAL WITH WIND OF SIGNIFICANCE WILL BE
KCPR. SOUTHWEST WIND AROUND 10KTS WILL HOLD STEADY OVERNIGHT. THIS
WIND WILL INCREASE AGAIN BETWEEN 14Z-16Z/THURSDAY WITH SPEEDS
14G20KTS ANTICIPATED. OTHER TERMINALS WILL SEE INCREASING SOUTH OR
EVEN SOUTHEAST FLOW DURING THE AFTERNOON WITH SPEEDS 6-10KTS.
&&

.FIRE WEATHER...

MAINLY DRY AND WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
MORNING FOR ALL AREAS. RELATIVE HUMIDITY WILL FALL INTO THE TEENS
FOR MANY LOWER ELEVATION LOCATIONS...BUT WINDS SHOULD REMAIN LIGHT
TO MODERATE. THE CHANCE OF SHOWERS WILL INCREASE IN THE WEST
THURSDAY AFTERNOON WITH A CHANCE OF THUNDERSTORMS FOR ALL AREAS ON
FRIDAY. A WETTING RAIN IS A GOOD POSSIBILITY FOR MANY AREAS FROM
FRIDAY NIGHT INTO THE WEEKEND. EXPECT MAINLY FAIR MIXING CONDITIONS
AND SMOKE DISPERSAL TODAY WITH FAIR TO GOOD SMOKE DISPERSAL THURSDAY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...PS
LONG TERM...PS
AVIATION...CNJ
FIRE WEATHER...PS




000
FXUS65 KRIW 041745
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 AM MDT WED MAY 4 2016

.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT

WITH THE UPCOMING ACTIVE WEATHER...WE WILL SPEND VERY LITTLE TIME ON
THE WEATHER THROUGH THURSDAY MORNING. WITH RIDGING STILL IN
CONTROL...IT CONTINUES TO LOOK VERY NICE WITH A GOOD DEAL OF
SUNSHINE AND WARM TEMPERATURES. ACROSS THE MOUNTAINS...ALTHOUGH WE
CAN NOT RULE OUT A SHOWER...THE CHANCE IS SO SMALL WE LEFT THE POPS
SILENT.

THINGS WILL BECOME A BIT MORE ACTIVE THURSDAY AFTERNOON AS AN UPPER
LEVEL LOW MOVING INTO CALIFORNIA THROWS SOME MID LEVEL MOISTURE INTO
THE AREA AND IT INTERACTS WITH SOME JET ENERGY TO PRODUCE A FEW
SHOWERS AND THUNDERSTORMS ACROSS AREAS WEST OF THE DIVIDE. AT THIS
TIME...COVERAGE DOES NOT LOOK THAT GREAT AND CONVECTION SHOULD BE
RESTRICTED TO WEST OF THE DIVIDE THROUGH THURSDAY. MEANWHILE...AREAS
EAST OF THE DIVIDE WILL HAVE ONE MORE DRY AND QUITE WARM DAY.
GUIDANCE NUMBERS CONTINUE TO CLIMB WITH THE OUTSIDE CHANCE THAT SOME
OF THE WARMER SPOTS LIKE GREYBULL COULD GET CLOSE TO 90.
SOUTHWESTERLY BREEZES WILL DEVELOP AHEAD OF THE FRONT...BUT NOTHING
UNUSUAL FOR WYOMING.

THINGS DEFINITELY GET MORE ACTIVE FOR FRIDAY. THE REGION WILL BE IN
A SQUEEZE PLAY AS A COLD FRONT DROPS SOUTHWARD OUT OF MONTANA AND
INTERACTS WITH THE MORE UNSTABLE AIR ACROSS THE AREA. MODELS ARE
SHOWING A DECENT AMOUNTS OF DIRECTION SHEAR IN THE AFTERNOON WITH
THE INSTABILITY AND SOME DECENT JET SUPPORT. THIS COULD LEAD TO SOME
STRONG AND POSSIBLY SEVERE STORMS IF A SHORTWAVE CAN CROSS AT THE
RIGHT TIME AND BRING A BIT OF EXTRA LIFT. THE STORM PREDICTION
CENTER HAS SOUTHWESTERN WYOMING UNDER A MARGINAL DAY 3 RISK.
CONTINUITY HAD THIS COVERED FAIRLY WELL SO WE LEFT IT ALONE.

THINGS THEN TRANSLATE TO A MORE STRATIFORM PRECIPITATION AT NIGHT AS
THE HEATING OF THE DAY AND INSTABILITY IS LOST. THE MODELS CONTINUE
TO BE RATHER ROBUST IN AMOUNTS OF RAIN WITH OVER A HALF AN INCH A
GOOD POSSIBLY OVERNIGHT IN AREAS FAVORED BY LOW LEVEL EASTERLY
FLOW. THROUGH FRIDAY NIGHT...THIS LOOKS TO BE MAINLY A RAIN EVENT
WITH 700 MILLIBAR TEMPERATURES EXPECTED TO REMAIN AT PLUS 2 OR
ABOVE. THIS WOULD PUT SNOW LEVELS AROUND 9500 OR ABOVE. THIS COULD
INCREASE FLOOD POTENTIAL IN SOME AREAS IF RAIN FALLS ON THE SNOWPACK
IN A PLACE LIKE THE WIND RIVER RANGE. STAY TUNED.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

SYNOPSIS...AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY LIFT
ACROSS THE GREAT BASIN AND CENTRAL ROCKIES OVER THE
WEEKEND...BRINGING CONTINUED WIDESPREAD RAIN AND MOUNTAIN SNOW
ACROSS MUCH OF THE AREA THROUGH SATURDAY NIGHT.  RAIN AND HIGHER
MOUNTAIN SNOW COULD BE QUITE ALONG THE EAST SLOPES OF THE DIVIDE AND
ADJACENT CENTRAL BASINS WITH SOME FLOODING POSSIBLE.  THE UPPER
LEVEL LOW PRESSURE SYSTEM WILL MOVE EAST INTO THE PLAINS ON MONDAY
WITH A COOL AND UNSETTLED NORTHWEST FLOW EXPECTED TO PREVAIL BEHIND
THIS SYSTEM THROUGH MID-WEEK.

DISCUSSION...MEDIUM-RANGE MODELS IN GOOD OVERALL AGREEMENT AT THE
OUTSET WITH REX BLOCK OVER THE INTERMOUNTAIN WEST...RIDGE OVER THE
NORTHERN ROCKIES AND CUTOFF NEAR LAS VEGAS 12Z SATURDAY. SPREAD
INCREASES LIFTING THE UPPER LOW NE INTO THE CENTRAL ROCKIES LATE IN
THE WEEKEND WITH THE ECMWF DISPLAYING THE NORTHERN MOST TRACK THIS
MORNING.  FORECAST CONTINUES TO BE WEIGHTED TOWARD THE MORE
CONSISTENT GFS/GEFS MEAN...TAKING UPPER LOW INTO THE FOUR CORNERS
REGION SUNDAY MORNING BEFORE JUMPING THE DIVIDE AND ENDING UP NEAR
GOODLAND KS ON MONDAY.  ALSO PREFER THE GFS EVOLUTION OF MORE WELL-
DEFINED HIGH AMPLITUDE RIDGE DEVELOPING ALONG 130W EARLY NEXT WEEK
WITH LOWERING HEIGHTS DOWNSTREAM ACROSS THE NORTHERN ROCKIES.

ON SATURDAY AND SUNDAY...AREA OF SIGNIFICANT WARM CONVEYOR
BELT/UPSLOPE PRECIPITATION IS EXPECTED TO DEVELOP ON THE NE QUADRANT
OF THE SW LOW FROM SOUTHEAST INTO CENTRAL WYOMING. PRECIPITATION
RATES ARE EXPECTED TO BE 0.50-1 INCH/6HR OVER AT LEAST A 24 HOUR
PERIOD ALONG THIS SWATH ARCING ROUGHLY FROM A CHEYENNE TO CASPER
(OR ALONG I25) LINE AND WESTWARD INTO THE EAST SLOPES OF THE WIND
RIVER AND SOUTHERN ABSAROKA RANGES. MAIN CONCERN CONTINUES TO BE
FLOODING POTENTIAL...WITH SNOW LEVELS EXPECTED TO BE BETWEEN
8.5-9KFT THROUGH SATURDAY EVENING BEFORE LOWERING SUNDAY MORNING
TO NEAR 8KFT. THE LITTLE WIND RIVER IS FORECAST BY THE MBRFC TO
CREST OVER A FOOT ABOVE FLOOD STAGE NEAR RIVERTON ON SUNDAY IF
THESE TEMPERATURES AND PRECIPITATION AMOUNTS PLAY OUT. 10 TO 20
INCHES OF SNOW IS FORECAST ABOVE 9000 FEET ACROSS THE WIND RIVER
AND SOUTHERN ABSAROKA RANGE FROM FRIDAY NIGHT THROUGH SUNDAY
MORNING.

MONDAY THROUGH WEDNESDAY...THERE IS DECREASING CONFIDENCE IN
PRECIPITATION PLACEMENT AND TIMING DURING THIS PERIOD.  WITH
PREFERRED GFS SCENARIO BETWEEN EXITING UPPER LOW AND NORTHERN STREAM
KICKER DIVING ACROSS THE NORTHERN ROCKIES...KEPT HIGHER POPS ACROSS
THE SOUTH AND WEST ON MONDAY GIVING EXITING UPPER LOW MORE
INFLUENCE...AND THEN TURNING ATTENTION TO THE NORTHERN STREAM KICKER
ON TUESDAY AND WEDNESDAY THAT WILL SPREAD SOME VALLEY RAIN AND
MOUNTAIN SNOW SHOWERS ACROSS MAINLY THE NORTH HALF OF THE CWA.

&&

.AVIATION.../18Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

CONTINUED VFR CONDITIONS AT ALL TERMINALS THROUGH MIDDAY THURSDAY.
INCREASING MOISTURE AHEAD OF THE UPPER LOW OFF THE CALIFORNIA COAST
WILL BEGIN TO LEAD TO MORE MID-LEVEL CLOUDINESS THURSDAY MORNING.
EXPECT SOME INCREASING SOUTH-SOUTHWEST WIND AROUND 8-11KTS AFTER 19Z-
21Z/TODAY. THESE DIURNAL WINDS WILL DECREASE THIS EVENING.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONTINUED VFR CONDITIONS AT ALL TERMINALS THROUGH MIDDAY THURSDAY.
OTHER THAN SOME INCREASING MID-CLOUD DECKS THURSDAY MORNING...LITTLE
CHANGE IS ANTICIPATED THROUGH 18Z/THURSDAY. ONLY KCPR WITH ANY WIND
OF SIGNIFICANCE THROUGH THE PERIOD. SOUTHWEST WIND AROUND 15KTS WILL
CONTINUE UNTIL 23Z/TODAY AND THEN HOLD STEADY AROUND 10KTS OVERNIGHT.
THIS WIND WILL INCREASE AGAIN BETWEEN 14Z-16Z/THURSDAY WITH SPEEDS
14G20KTS ANTICIPATED.

&&

.FIRE WEATHER...

MAINLY DRY AND WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
MORNING FOR ALL AREAS. RELATIVE HUMIDITY WILL FALL INTO THE TEENS
FOR MANY LOWER ELEVATION LOCATIONS...BUT WINDS SHOULD REMAIN LIGHT
TO MODERATE. THE CHANCE OF SHOWERS WILL INCREASE IN THE WEST
THURSDAY AFTERNOON WITH A CHANCE OF THUNDERSTORMS FOR ALL AREAS ON
FRIDAY. A WETTING RAIN IS A GOOD POSSIBILITY FOR MANY AREAS FROM
FRIDAY NIGHT INTO THE WEEKEND. EXPECT MAINLY FAIR MIXING CONDITIONS
AND SMOKE DISPERSAL TODAY WITH FAIR TO GOOD SMOKE DISPERSAL
THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HATTINGS
LONG TERM...AEM
AVIATION...CNJ
FIRE WEATHER...HATTINGS




000
FXUS65 KRIW 041745
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 AM MDT WED MAY 4 2016

.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT

WITH THE UPCOMING ACTIVE WEATHER...WE WILL SPEND VERY LITTLE TIME ON
THE WEATHER THROUGH THURSDAY MORNING. WITH RIDGING STILL IN
CONTROL...IT CONTINUES TO LOOK VERY NICE WITH A GOOD DEAL OF
SUNSHINE AND WARM TEMPERATURES. ACROSS THE MOUNTAINS...ALTHOUGH WE
CAN NOT RULE OUT A SHOWER...THE CHANCE IS SO SMALL WE LEFT THE POPS
SILENT.

THINGS WILL BECOME A BIT MORE ACTIVE THURSDAY AFTERNOON AS AN UPPER
LEVEL LOW MOVING INTO CALIFORNIA THROWS SOME MID LEVEL MOISTURE INTO
THE AREA AND IT INTERACTS WITH SOME JET ENERGY TO PRODUCE A FEW
SHOWERS AND THUNDERSTORMS ACROSS AREAS WEST OF THE DIVIDE. AT THIS
TIME...COVERAGE DOES NOT LOOK THAT GREAT AND CONVECTION SHOULD BE
RESTRICTED TO WEST OF THE DIVIDE THROUGH THURSDAY. MEANWHILE...AREAS
EAST OF THE DIVIDE WILL HAVE ONE MORE DRY AND QUITE WARM DAY.
GUIDANCE NUMBERS CONTINUE TO CLIMB WITH THE OUTSIDE CHANCE THAT SOME
OF THE WARMER SPOTS LIKE GREYBULL COULD GET CLOSE TO 90.
SOUTHWESTERLY BREEZES WILL DEVELOP AHEAD OF THE FRONT...BUT NOTHING
UNUSUAL FOR WYOMING.

THINGS DEFINITELY GET MORE ACTIVE FOR FRIDAY. THE REGION WILL BE IN
A SQUEEZE PLAY AS A COLD FRONT DROPS SOUTHWARD OUT OF MONTANA AND
INTERACTS WITH THE MORE UNSTABLE AIR ACROSS THE AREA. MODELS ARE
SHOWING A DECENT AMOUNTS OF DIRECTION SHEAR IN THE AFTERNOON WITH
THE INSTABILITY AND SOME DECENT JET SUPPORT. THIS COULD LEAD TO SOME
STRONG AND POSSIBLY SEVERE STORMS IF A SHORTWAVE CAN CROSS AT THE
RIGHT TIME AND BRING A BIT OF EXTRA LIFT. THE STORM PREDICTION
CENTER HAS SOUTHWESTERN WYOMING UNDER A MARGINAL DAY 3 RISK.
CONTINUITY HAD THIS COVERED FAIRLY WELL SO WE LEFT IT ALONE.

THINGS THEN TRANSLATE TO A MORE STRATIFORM PRECIPITATION AT NIGHT AS
THE HEATING OF THE DAY AND INSTABILITY IS LOST. THE MODELS CONTINUE
TO BE RATHER ROBUST IN AMOUNTS OF RAIN WITH OVER A HALF AN INCH A
GOOD POSSIBLY OVERNIGHT IN AREAS FAVORED BY LOW LEVEL EASTERLY
FLOW. THROUGH FRIDAY NIGHT...THIS LOOKS TO BE MAINLY A RAIN EVENT
WITH 700 MILLIBAR TEMPERATURES EXPECTED TO REMAIN AT PLUS 2 OR
ABOVE. THIS WOULD PUT SNOW LEVELS AROUND 9500 OR ABOVE. THIS COULD
INCREASE FLOOD POTENTIAL IN SOME AREAS IF RAIN FALLS ON THE SNOWPACK
IN A PLACE LIKE THE WIND RIVER RANGE. STAY TUNED.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

SYNOPSIS...AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY LIFT
ACROSS THE GREAT BASIN AND CENTRAL ROCKIES OVER THE
WEEKEND...BRINGING CONTINUED WIDESPREAD RAIN AND MOUNTAIN SNOW
ACROSS MUCH OF THE AREA THROUGH SATURDAY NIGHT.  RAIN AND HIGHER
MOUNTAIN SNOW COULD BE QUITE ALONG THE EAST SLOPES OF THE DIVIDE AND
ADJACENT CENTRAL BASINS WITH SOME FLOODING POSSIBLE.  THE UPPER
LEVEL LOW PRESSURE SYSTEM WILL MOVE EAST INTO THE PLAINS ON MONDAY
WITH A COOL AND UNSETTLED NORTHWEST FLOW EXPECTED TO PREVAIL BEHIND
THIS SYSTEM THROUGH MID-WEEK.

DISCUSSION...MEDIUM-RANGE MODELS IN GOOD OVERALL AGREEMENT AT THE
OUTSET WITH REX BLOCK OVER THE INTERMOUNTAIN WEST...RIDGE OVER THE
NORTHERN ROCKIES AND CUTOFF NEAR LAS VEGAS 12Z SATURDAY. SPREAD
INCREASES LIFTING THE UPPER LOW NE INTO THE CENTRAL ROCKIES LATE IN
THE WEEKEND WITH THE ECMWF DISPLAYING THE NORTHERN MOST TRACK THIS
MORNING.  FORECAST CONTINUES TO BE WEIGHTED TOWARD THE MORE
CONSISTENT GFS/GEFS MEAN...TAKING UPPER LOW INTO THE FOUR CORNERS
REGION SUNDAY MORNING BEFORE JUMPING THE DIVIDE AND ENDING UP NEAR
GOODLAND KS ON MONDAY.  ALSO PREFER THE GFS EVOLUTION OF MORE WELL-
DEFINED HIGH AMPLITUDE RIDGE DEVELOPING ALONG 130W EARLY NEXT WEEK
WITH LOWERING HEIGHTS DOWNSTREAM ACROSS THE NORTHERN ROCKIES.

ON SATURDAY AND SUNDAY...AREA OF SIGNIFICANT WARM CONVEYOR
BELT/UPSLOPE PRECIPITATION IS EXPECTED TO DEVELOP ON THE NE QUADRANT
OF THE SW LOW FROM SOUTHEAST INTO CENTRAL WYOMING. PRECIPITATION
RATES ARE EXPECTED TO BE 0.50-1 INCH/6HR OVER AT LEAST A 24 HOUR
PERIOD ALONG THIS SWATH ARCING ROUGHLY FROM A CHEYENNE TO CASPER
(OR ALONG I25) LINE AND WESTWARD INTO THE EAST SLOPES OF THE WIND
RIVER AND SOUTHERN ABSAROKA RANGES. MAIN CONCERN CONTINUES TO BE
FLOODING POTENTIAL...WITH SNOW LEVELS EXPECTED TO BE BETWEEN
8.5-9KFT THROUGH SATURDAY EVENING BEFORE LOWERING SUNDAY MORNING
TO NEAR 8KFT. THE LITTLE WIND RIVER IS FORECAST BY THE MBRFC TO
CREST OVER A FOOT ABOVE FLOOD STAGE NEAR RIVERTON ON SUNDAY IF
THESE TEMPERATURES AND PRECIPITATION AMOUNTS PLAY OUT. 10 TO 20
INCHES OF SNOW IS FORECAST ABOVE 9000 FEET ACROSS THE WIND RIVER
AND SOUTHERN ABSAROKA RANGE FROM FRIDAY NIGHT THROUGH SUNDAY
MORNING.

MONDAY THROUGH WEDNESDAY...THERE IS DECREASING CONFIDENCE IN
PRECIPITATION PLACEMENT AND TIMING DURING THIS PERIOD.  WITH
PREFERRED GFS SCENARIO BETWEEN EXITING UPPER LOW AND NORTHERN STREAM
KICKER DIVING ACROSS THE NORTHERN ROCKIES...KEPT HIGHER POPS ACROSS
THE SOUTH AND WEST ON MONDAY GIVING EXITING UPPER LOW MORE
INFLUENCE...AND THEN TURNING ATTENTION TO THE NORTHERN STREAM KICKER
ON TUESDAY AND WEDNESDAY THAT WILL SPREAD SOME VALLEY RAIN AND
MOUNTAIN SNOW SHOWERS ACROSS MAINLY THE NORTH HALF OF THE CWA.

&&

.AVIATION.../18Z ISSUANCE/

WEST OF THE CONTINENTAL DIVIDE...KJAC/KRKS/KPNA/KBPI AIRPORTS

CONTINUED VFR CONDITIONS AT ALL TERMINALS THROUGH MIDDAY THURSDAY.
INCREASING MOISTURE AHEAD OF THE UPPER LOW OFF THE CALIFORNIA COAST
WILL BEGIN TO LEAD TO MORE MID-LEVEL CLOUDINESS THURSDAY MORNING.
EXPECT SOME INCREASING SOUTH-SOUTHWEST WIND AROUND 8-11KTS AFTER 19Z-
21Z/TODAY. THESE DIURNAL WINDS WILL DECREASE THIS EVENING.

EAST OF THE CONTINENTAL DIVIDE...KCPR/KCOD/KRIW/KWRL/KLND AIRPORTS

CONTINUED VFR CONDITIONS AT ALL TERMINALS THROUGH MIDDAY THURSDAY.
OTHER THAN SOME INCREASING MID-CLOUD DECKS THURSDAY MORNING...LITTLE
CHANGE IS ANTICIPATED THROUGH 18Z/THURSDAY. ONLY KCPR WITH ANY WIND
OF SIGNIFICANCE THROUGH THE PERIOD. SOUTHWEST WIND AROUND 15KTS WILL
CONTINUE UNTIL 23Z/TODAY AND THEN HOLD STEADY AROUND 10KTS OVERNIGHT.
THIS WIND WILL INCREASE AGAIN BETWEEN 14Z-16Z/THURSDAY WITH SPEEDS
14G20KTS ANTICIPATED.

&&

.FIRE WEATHER...

MAINLY DRY AND WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
MORNING FOR ALL AREAS. RELATIVE HUMIDITY WILL FALL INTO THE TEENS
FOR MANY LOWER ELEVATION LOCATIONS...BUT WINDS SHOULD REMAIN LIGHT
TO MODERATE. THE CHANCE OF SHOWERS WILL INCREASE IN THE WEST
THURSDAY AFTERNOON WITH A CHANCE OF THUNDERSTORMS FOR ALL AREAS ON
FRIDAY. A WETTING RAIN IS A GOOD POSSIBILITY FOR MANY AREAS FROM
FRIDAY NIGHT INTO THE WEEKEND. EXPECT MAINLY FAIR MIXING CONDITIONS
AND SMOKE DISPERSAL TODAY WITH FAIR TO GOOD SMOKE DISPERSAL
THURSDAY.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HATTINGS
LONG TERM...AEM
AVIATION...CNJ
FIRE WEATHER...HATTINGS




000
FXUS65 KCYS 041733
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1133 AM MDT WED MAY 4 2016

.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 300 AM MDT WED MAY 4 2016

PRETTY QUIET AND PLEASANT WEATHER IN STORE FOR MUCH OF THE SHORT
TERM.  UPPER LEVEL RIDGE AXIS WILL BE OVER WYOMING TODAY AND
THURSDAY WITH WEAK SFC PRESSURE GRADIENTS AND WEAK WINDS ALOFT.  700
MB TEMPS WILL RISE TO AROUND 5C BY THIS AFTN AND THEN 9C BY THURS
AFTN.  THIS WILL TRANSLATE INTO WIDESPREAD HIGHS IN THE MID 70S TO
MID 80S BY THURSDAY FOR AREAS TO THE EAST OF THE LARAMIE RANGE.
INSTABILITY IS REALLY LIMITED THROUGH THURSDAY SO KEPT SLIGHT CHANCE
POPS OUT OF THE FCST.  THE COMBINATION OF ABOVE NORMAL TEMPS...LACK
OF WINDS...AND LACK OF PRECIPITATION WILL MAKE THE NEXT TWO DAYS
SOME OF THE NICEST WE HAVE SEEN SO FAR THIS SPRING.

THE RIDGE AXIS WILL SLIDE EASTWARD INTO NEBRASKA BY FRIDAY.
SOUTHERLY FLOW ALOFT WILL DEVELOP OVER THE CWA IN ADVANCE OF THE
CLOSED LOW OVER THE SOUTHWESTERN U.S.  SOUTHEASTERLY WINDS
DEVELOPING DURING THE AFTN WILL ADVECT HIGHER DEWPOINTS INTO THE
REGION.  CAPE VALUES RISE TO 500-750 J/KG BY FRIDAY AFTERNOON...THUS
WILL SEE ISOLATED TO SCATTERED CONVECTION...AIDED BY COOLING ALOFT.
CONVECTION COULD LAST WELL INTO THE EVENING/EARLY NIGHT.  WHILE
THERE COULD BE A STRONGER STORM WITH SMALL HAIL...THE OVERALL SVR
THREAT WILL BE LIMITED ON FRIDAY BY MARGINAL INSTABILITY AND ONLY
MODEST MIDLVL FLOW/DEEP LAYER SHEAR.

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 300 AM MDT WED MAY 4 2016

ANOTHER ROUND OF UNSETTLED WEATHER TO IMPACT THE FORECAST AREA
THIS WEEKEND AND EARLY NEXT WEEK. A BROAD AND SLOW MOVING UPPER
LEVEL TROUGH WILL SLOWLY DRIFT ACROSS THE ROCKY MOUNTAIN
REGION...PRODUCING WIDESPREAD PRECIPITATION. TEMPERATURES ALOFT
WITH THIS TROUGH WILL BE A GOOD DEAL WARMER THAN LAST WEEKS
SYSTEM...SUCH THAT PRECIPITATION WILL MAINLY FALL AS RAIN OUTSIDE
OF THE MOUNTAINS.

TO THIS POINT THE MODELS ARE STILL TRYING TO RESOLVE SMALLER
SCALE FEATURES EMBEDDED WITHIN THE UPPER TROUGH. THEREFORE
CONFIDENCE IS LOW AS TO EXACT TIMING FOR PRECIPITATION BUT SAFE TO
SAY MOST OF THE AREA WILL SEE SOME PRECIPITATION SATURDAY...
SUNDAY...AND MONDAY. THERE WILL BE A CHANCE FOR THUNDERSTORMS OVER
THIS TIME FRAME. BASED ON CURRENT MODEL DATA THE SEVERE
THUNDERSTORM THREAT IS LOW BUT THAT THREAT WILL BE SOMETHING TO
MONITOR AS THE WEEKEND APPROACHES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM MDT WED MAY 4 2016

VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL THROUGH THE PERIOD.
HOWEVER...COULD SEE OCCASIONAL GUSTS TO 20 KTS AT KRWL THIS
AFTERNOON...AND AT KCDR AFTER 05Z.

&&

.FIRE WEATHER...
ISSUED AT 207 AM MDT WED MAY 4 2016

MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS.  TEMPERATURES
WILL BE ABOVE NORMAL THROUGH FRIDAY.  MINIMUM AFTERNOON HUMIDITY
VALUES WILL DROP TO AROUND 20 PERCENT ON THURSDAY...HOWEVER WINDS
WILL BE LIGHT.  A BETTER CHANCE OF WIDESPREAD RAIN WILL OCCUR BY
FRIDAY EVENING INTO SUNDAY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...ZF
LONG TERM...SML
AVIATION...RJM
FIRE WEATHER...ZF




000
FXUS63 KUNR 041713
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1113 AM MDT WED MAY 4 2016

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 231 AM MDT WED MAY 4 2016

08Z SURFACE ANALYSIS HAD WEAK HIGH OVER THE DAKOTAS WITH MAINLY
CLEAR SKIES OVER THE CWA. WATER VAPOR SHOWED UPPER RIDGE
DOMINATING WEATHER OVER THE ROCKIES. THIS RIDGE WILL SHIFT OVER
THE NORTHERN PLAINS WEDNESDAY/THURSDAY.

TODAY...SURFACE HIGH SHIFTS EAST WITH RETURN FLOW OVER THE CWA.
CONVERGENCE OVER THE BLACK HILLS MAY RESULT IN AN ISOLATED -TSRA
GIVEN 250-500J/KG SBCAPE AND VERY WEAK SBCIN LATE THIS AFTERNOON.
CONVECTIVE ALLOWING MODELS HINT AT THIS SCENARIO. TEMPERATURES WILL
BE ABOUT 5F WARMER THAN TUESDAY GIVEN WARM AIR ADVECTION/THICKNESS
INCREASES.

TONIGHT/THURSDAY...WARM AIR ADVECTION CONTINUES WITH NICE WEATHER ON
TAP. HIGHS THURSDAY WILL BE ABOUT 10F HIGHER THAN WEDNESDAY WITH
WIDESPREAD 80S. CIN/SUBSIDENCE SHOULD BE SUFFICIENT TO SUPPRESS
CONVECTION EVEN WITH MODEST INSTABILITY FORECAST.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 231 AM MDT WED MAY 4 2016

UPPER RIDGE BEGINS TO BREAK DOWN ON FRIDAY AS A STRONG UPPER LOW
MOVES ONSHORE OVER SOUTHERN CALIFORNIA. THIS UPPER LOW WILL MOVE
INTO THE CENTRAL ROCKIES BY SUNDAY AND THEN DRIFT SLOWLY EASTWARD
ACROSS SOUTHERN SOUTH DAKOTA/NORTHERN NEBRASKA EARLY NEXT WEEK.
AFTER THIS LOW EXITS...ANOTHER UPPER LOW DROPS SOUTH FROM THE
PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES ON TUESDAY...BEFORE
MOVING ACROSS THE NORTHERN PLAINS ON WEDNESDAY AND THURSDAY.
OVERALL THIS PATTERN WILL LEAD TO NEAR DAILY CHANCES FOR
SHOWERS/STORMS AND COOLER...BUT SEASONAL TEMPERATURES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1112 AM MDT WED MAY 4 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 231 AM MDT WED MAY 4 2016

AVERAGE MINIMUM RELATIVE HUMIDITIES WILL DROP TO THE UPPER TEENS
TO UPPER 20S TODAY AND MID TEENS TO MID 20S THURSDAY. WINDS WILL
SWITCH TO THE SOUTH TODAY AND AVERAGE 10 TO 15 MPH THROUGH
THURSDAY...WITH SOME LOCATIONS OVER SOUTHERN SOUTH DAKOTA REACHING
10 TO 20 MPH THURSDAY.

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...BUNKERS
FIRE WEATHER...HELGESON




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