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000
FXUS65 KCYS 201119
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
519 AM MDT SUN APR 20 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)

ISSUED AT 334 AM MDT SUN APR 20 2014

WATER VAPOR IMAGERY FROM EARLY THIS MORNING SHOWS DRIER AIR AND
SUBSIDENCE MOVING OVER THE REGION WITH JUST SOME SCT MID CLOUDS
MOVING OVER THE FORECAST AREA. A FAIRLY STRONG UPPER LEVEL SHORTWAVE
CURRENTLY OVER THE NORTHERN ROCKIES WILL MOVE ACROSS THE US/CANADIAN
BORDER TODAY. THE ATTENDANT PACIFIC COLD FRONT IS CURRENTLY DRAPED
FROM WESTERN MONTANA DOWN INTO NORTHERN NEVADA...AND WILL MOVE
ACROSS THE PLAINS ROUGHLY BETWEEN 18 AND 00Z AND BACK INTO
THE MOUNTAINS THROUGH 06Z. TEMPS WILL INCREASE BACK INTO THE 60S AND
70S AHEAD OF THE FRONT WHILE A WEAK UPPER LEVEL IMPULSE IN ZONAL
FLOW ALOFT APPROACHES FROM THE WEST. THE COMBINATION OF FEATURES
IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND TSTORMS TO THE HIGH
COUNTRY AND ALONG THE CHEYENNE RIDGE LATE IN THE AFTERNOON. THE NAM
AND ECMWF ARE A BIT MORE BULLISH WITH INSTABILITY THIS AFTERNOON VS
THE GFS...WITH LI`S DROPPING TO BETWEEN MINUS 1 AND MINUS 2. BUT
TIMING OF THE FRONT AND SUBSIDENCE AHEAD OF THE DISTURBANCE LOOKS TO
LIMIT CONVECTION ACROSS THE PLAINS. NOT WHOLLY CONVINCE THERE WONT
BE A STRAY SHOWER OR TWO ALONG THE FRONT AS IT TREKS SOUTH ACROSS
THIS AREA...BUT CHANCES ARE LOW ENOUGH TO WILL KEEP MENTION OUT OF
THE FORECAST.

COOLER TEMPS AND WEAK SOUTHEASTERLY RETURN FLOW WILL KEEP CONDITIONS
DRY FOR THE MOST PART ON MONDAY...WITH ONLY A SLIGHT CHANCE FOR RAIN
SHOWERS WITHIN CONVERGENT SFC FLOW DEVELOPING ALONG THE LARAMIE
RANGE. OTHERWISE...MONDAY LOOKS TO BE A FAIRLY CALM AND PLEASANT
DAY. FLOW ALOFT WILL INCREASE AND BACK TO THE SOUTHWEST AHEAD OF A
RATHER STRONG UPPER TROUGH MOVING ACROSS THE GREAT BASIN MONDAY
NIGHT AND TUESDAY. THE LEESIDE PRESSURE TROUGH WILL STRENGTHEN AHEAD
OF THIS WAVE...WITH INCREASING SOUTHERLY SFC FLOW ADVECTING UPPER
30S TO 40S DEW POINTS INTO THE PANHANDLE ON TUESDAY. A PIECE OF
ENERGY EJECTING OUT AHEAD OF THE TROUGH WILL MOVE OVER THE CWA
TUESDAY AFTERNOON WITH 700MB TEMPS INCREASING TO BETWEEN 7 AND 9C.
SO...EXPECT A BROADER COVERAGE OF CONVECTION TO DEVELOP IN THE
AFTERNOON WITH THE COMBINATION OF ENERGY ALOFT...OROGRAPHICS...AND
SFC CONVERGENCE ALONG THE LEESIDE TROUGH. WILL MAINTAIN ONLY SLIGHT
CHANCE TO CHANCE FOR TSTORMS FOR NOW THO AS WAA ALOFT AND POSSIBLE
MIDLEVEL DRY SLOTTING COULD LIMIT OVERALL EXPANSE AND INTENSITY OF
CONVECTION. BUT...WILL HAVE TO WATCH THIS SYSTEM CLOSELY FOR THE
POTENTIAL A FEW STRONGER STORMS MAY DEVELOP ACROSS THE PANHANDLE
WHERE LLVL MOISTURE AND COOLER TEMPS ALOFT WILL BE IN PLACE.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 334 AM MDT SUN APR 20 2014

WINDS CONTINUE TO BE THE MAIN FORECAST CHALLENGE IN THE LONG
TERM...FOLLOWED BY THUNDERSTORM CHANCES.

STARTING OFF TUESDAY NIGHT...LOOKS LIKE WE SHOULD SEE ONGOING
CONVECTION MOVING OUT INTO THE PANHANDLE TUESDAY EVENING. NAM
SHOWING 40 TO LOW 50 DEWPOINTS IN THE PANHANDLE TUESDAY NIGHT. GFS
AND NAM SHOWING FAIRLY WIDESPREAD QPF ENDING AROUND 06Z. WENT
AHEAD WITH CHANCE POPS AS IT REMAINS UNSTABLE OUT THERE THROUGH
THE EVENING HOURS. NAM FORECASTING LIFTED INDICES OF -3 TO -4C. TO
THE WEST...A STRONG SHORTWAVE TRACKS THROUGH WESTERN WYOMING WITH
A COLD FRONT FORECAST TO MOVE JUST WEST OF CARBON COUNTY TUESDAY
EVENING. FAIRLY UNSTABLE CONDITIONS OUT THAT WAY TOO...SO A
COMBINATION OF UNSTABLE AIR AND UPSLOPING CONDITIONS SHOULD GIVE
US FAIRLY GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS.

SHORTWAVE TRACKS INTO EASTERN MONTANA BY 12Z WEDNESDAY. COLD FRONT
LOOKS TO MOVE THROUGH SOUTHEAST WYOMING THROUGH THE DAY WEDNESDAY
WITH 700MB WINDS REALLY RAMPING UP BEHIND THE FRONT. BOTH THE GFS
AND ECMWF SHOWING 700MB WINDS INCREASING TO 45 TO 50KTS BEHIND
THIS FRONT. GUIDANCE HAS BEEN SHOWING THIS HAPPENING FOR SEVERAL
MODEL RUNS NOW...SO CONFIDENCE IS GROWING THAT WE WILL AT LEAST
SEE OUR WIND PRONE AREAS HITTING WARNING CRITERIA WEDNESDAY
AFTERNOON AND MAYBE AS EARLY AS WEDNESDAY MORNING IF THE ECMWF
SOLUTION COMES TRUE.

WINDS REMAIN ELEVATED THURSDAY INTO FRIDAY AS THE GFS AND TO A
LESSER EXTENT THE ECMWF KEEP 700MB WINDS OF 40KTS OR HIGHER. BY
FRIDAY MORNING...A SURFACE LOW MOVES INTO NORTH CENTRAL
WYOMING...EASING THE GRADIENT AND WINDS THROUGH FRIDAY AFTERNOON.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 516 AM MDT SUN APR 20 2014

LOOKS LIKE WE COULD SEE ISOLATED TSTMS AND SCATTERED SHOWERS FOR
AIRPORTS ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON. DO
THINK FOR THE MOST PART THAT CONDITIONS WILL STAY VFR AND THAT IS
WHAT WE HAVE IN THE TERMINAL FORECASTS FOR KCYS...KLAR AND KRWL.
VFR IN THE PANHANDLE A PRETTY SURE BET AS CONVECTION WILL BE WEST
OVER CENTRAL WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 334 AM MDT SUN APR 20 2014

THIS AFTERNOON WILL SEE A CHANCE FOR SHOWERS AND TSTORMS MAINLY
ALONG AND WEST OF INTERSTATE 25...WITH WETTING RAINS LIKELY FROM
THIS ACTIVITY. HUMIDITY VALUES WILL GENERALLY STAY ABOVE 20
PERCENT DURING THE AFTERNOON HOURS TODAY THROUGH
MIDWEEK...ALTHOUGH HUMIDITIES MAY DROP TO 15 PERCENT ACROSS FAR
WESTERN PORTIONS OF CARBON COUNTY ON MONDAY. GOOD RECOVERIES ARE
EXPECTED AT NIGHT. ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS IS
POSSIBLE ON TUESDAY...WITH GUSTY WINDS LIKELY TUESDAY AND
WEDNESDAY.

&&

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

$$

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






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000
FXUS65 KRIW 201025
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
425 AM MDT SUN APR 20 2014

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

SAT IMAGERY STILL SHOWING SPLIT UPR WAVE PATTERN ACROSS THE CONUS.
WY CURRENTLY UNDER WEAK NEARLY ZONAL FLOW W/ RIDGE N AND TROF OF THE
STATE. UPSTREAM GETTING INTO THE PAC NW...STRONG JET NOSING INTO
THAT REGION...GETTING READY TO FOLD AS LARGE TROF ROTATES AROUND AK
GULF LOW. AT THE SFC...WEAK GRADIENT W/ LOW P TO THE WEST AND
TROF/FRONT STILL HANGING AROUND THE SRN FORECAST AREA...LIFTING NWD
SLOWLY.

NICE WARM AND LOW IMPACT EASTER SUNDAY OVERALL. THE AFTERNOON WILL
OFFER LOW END CHANCES FOR ISOLATED TO WIDELY SCATTERED SHOWERS WITH
SOME THUNDER AS A WEAK UPR LVL DISTURBANCE AND STALLED SFC FRONT
RACE BACK S THROUGH THE FA. TIMING AND LOW END AVAILABLE MOISTURE
WILL LIMIT THE CONVECTIVE AREA TO MAINLY THE S CNTRL...SRN AND SERN
ZONES. HOWEVER...THIS WILL BE ANOTHER CASE OF HIGH BASED SHOWERS/FEW
STORMS WITH LITTLE RAIN...AND MORE GUSTY WINDS.

MONDAY THRU MOST OF THE DAY...UPR RIDGE AND STABLE ATMOSPHERE IN
PLACE. MONDAY NIGHT...UPR RIDGE AXIS STARTS TO HEAD OUT WHILE TROF
FROM THE WEST BEGINS TO MOVE IN AND PVA BEGINS TO ENTER THE WRN
PORTION OF THE STATE. LEAD VORT MAX ASSOCIATED WITH PORTION JET/TROF
MENTIONED ABOVE WILL THEN WORK ITS WAY INTO THE WRN MOUNTAINS WITH
SOME PAC MOISTURE/PRECIP LATE MONDAY NIGHT/TUE MORNING.

TUESDAY THEN WILL HERALD THE BEGINNING OF NEW CYCLOGENESIS FROM THE
PAC NW INTO THE NRN GREAT BASIN AS THE STRONGER DYNAMICS FROM THE
SYSTEM IN AK GULF MOVE IN. THE ADDITION OF MODEST MID LVL MOISTURE
INTO AN INCREASING UNSTABLE ATMOSPHERE W/ VERY STEEP LAPSE RATES
WILL GIVE CHANCES FOR ISOLATED TO SCATTERED CONVECTION BY THE
AFTERNOON ACROSS MOST OF THE CWA. AN ISOLATED STRONG STORM COULD BE
POSSIBLE SOMEWHERE IN ERN JOHNSON COUNTY TUE AFTERNOON/EVE ALONG
NEAR PREFRONTAL/LEE TROF...IF MOISTURE RETURN GETS BACK NEAR THIS
REGION. WARRANTS KEEPING AN EYE ON THIS AREA FOR THE NEXT FEW
DAYS. OTHERWISE...THE BEST CHANCE FOR MORE SIGNIFICANT
PRECIPITATION WILL OCCUR ACROSS THE WRN MOUNTAINS AS INCREASING
MOISTURE AND OROGRAPHIC LIFTING COMBINES W/ DECENT UPR JET
DYNAMICS TO YIELD A GOOD REGION OF QG FORCING AS A STRONG CYCLONE
FORMS TO OUR NORTH INTO MT BY THE END OF THIS PERIOD. THE CURRENT
FCST PLACEMENT OF THE INCOMING TROF/JET DYNAMICS SUGGEST A SIMILAR
TRACK TO THAT OF A FEW DAYS AGO...W/ SPLIT CYCLONE
DEVELOPMENT...ONE TO THE N AND THE OTHER IN THE LEE OF THE CNTRL
ROCKIES. RESULTS WILL LIKELY BE SIMILAR OVERALL...WITH MOST
PRECIP...LIQUID/FROZEN...IN THE MOUNTAINS...AND MUCH LESS
EVERYWHERE ELSE.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

PACIFIC COLD FRONT WILL PUSH ACROSS AREA TUESDAY NIGHT INTO THE HIGH
PLAINS BY 12Z WEDNESDAY. ASSOCIATED UPPER TROUGH CLOSES OFF WITH
STACKED LOW FORMING NEAR HAVRE 18Z WEDNESDAY.  GFS KEEPS MORE ENERGY
ROTATING SOUTH OF THIS UPPER LOW BUT TREND IS TOWARD CONSOLIDATION
OVER NORTH CENTRAL MONTANA.  THUS...THIS IS LOOKING MORE LIKE A
DOWNSLOPE WIND EVENT WITH AND BEHIND THE FRONTAL PASSAGE EAST OF THE
DIVIDE WEDNESDAY MORNING WITH TIGHT W-E PRESSURE GRADIENT AND COLD AIR
SPILLING DOWN THE EAST SLOPES. MOST FAVORABLE AREAS FOR NEAR HIGH
WIND CRITERIA WILL BE FROM THE SOUTHERN ENDS OF THE ABSAROKA AND
BIGHORN RANGES TO THE INTERSTATE 80 CORRIDOR. OUT WEST...THE
HEAVIEST PERIOD OF SNOWFALL WILL OCCUR WITH THE FRONTAL PASSAGE
TUESDAY NIGHT...THOUGH NUMEROUS SNOW SHOWERS WILL WRAP AROUND THE
BACKSIDE OF THE LOW INTO NW WY ON WEDNESDAY...MAINLY FROM
TETON/TOGWOTEE PASS NORTHWARD. THE EC`S MORE STACKED UPPER LOW
RESULTS IN A MUCH MILDER AIRMASS OVER WYOMING WEDNESDAY AFTERNOON AS COLD
POOL LIFTS INTO MONTANA...H7 TEMPS -2C TO -5C EAST OF THE DIVIDE.
WITH DOWNSLOPE DRY ADIABATIC WARMING...HIGH TEMPERATURES WERE
BUMPED UP A FEW DEGREES ACROSS CENTRAL AREAS AND POPS LOWERED TO
MAINLY ISOLATED ACROSS THE LOWER ELEVATIONS EXCEPT CLOSER TO THE
DIVIDE WHERE SOME BLOW-OVER RAIN SHOWERS ARE LIKELY. GFS AND EC
BOTH SLIDE THE MAIN UPPER LOW TO NEAR GGW BY 12Z THURSDAY WITH
TRAILING SHORTWAVE SWINGING SE ACROSS WYOMING WEDNESDAY
NIGHT...BRINGING ANOTHER SHOT OF SNOW SHOWERS TO THE WEST AND
BIGHORNS AND MAINLY ISOLATED RAIN AND SNOW SHOWERS EAST OF THE
DIVIDE IN CONTINUED DOWNSLOPE FLOW.

UPPER RIDGE BUILDS IN TO THE ROCKIES THURSDAY...GETTING SQUEEZED
BETWEEN SLOW-MOVING LOW EXITING ACROSS THE NORTHERN PLAINS AND NEXT
PACIFIC SYSTEM SHEARING ONTO THE NW COAST.   WNW BREEZES WILL
CONTINUE ACROSS THE AREA THOUGH NOT NEARLY AS STRONG AS WEDNESDAY
WITH CHANCE POPS IN THE NORTHERN MTNS.

UPPER RIDGE SLOWLY PROGRESSES ACROSS THE PLAINS FRIDAY AND THROUGH
THE WEEKEND.  THIS NEXT SERIES OF PACIFIC SYSTEMS LOOKS TO SPLIT AS
THEY HEAD INTO THIS RIDGE.  THE GFS IS MUCH STRONGER AND SLOWER WITH
THE SOUTHERN STREAM THAN ECMWF.  HOWEVER...ZONAL FLOW...STRONG W-E
JET STREAM ALONG 40N FROM THE CENTRAL PACIFIC INTO THE WEST COAST
WILL TAKE SHAPE BY SATURDAY WITH JET GRADUALLY NOSING INTO THE
WESTERN GREAT BASIN SUNDAY.  THIS FAVORS THE FASTER ECMWF
GUIDANCE...SEVERAL FAST-MOVING SHORTWAVES WITH LOW CONFIDENCE IN
TIMING ON DAYS 6-8.  THIS PATTERN WILL BRING THE BEST CHANCES OF
RAIN AND SNOW TO THE WEST FRIDAY THROUGH SUNDAY.  MILD AND
OCCASIONAL BREEZY/WINDY CONDITIONS WILL PREVAIL EAST OF THE DIVIDE
WITH SLIGHT CHANCES OF SHOWERS.


&&

.AVIATION.../12Z ISSUANCE/

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

VFR CONDITIONS WILL OCCUR TODAY AND TONIGHT. ISOLATED SHOWERS ARE
POSSIBLE ACROSS SOUTHERN NATRONA COUNTY FROM 21Z UNTIL 02Z. THE
SHOWERS ARE NOT FORECAST TO HIT THE KCPR AIRPORT. A COLD FRONT WILL
PUSH THROUGH NORTHERN WY FROM 15Z TO 19Z AND PUSH SOUTH INTO CENTRAL
WY AROUND 00Z. A WIND SHIFT TO THE NORTH WILL BE THE MAIN IMPACT.

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

VFR CONDITIONS WILL OCCUR TODAY AND TONIGHT. ISOLATED SHOWERS WILL
BE POSSIBLE OVER THE NW WY MOUNTAINS UNTIL 18Z. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHERN WY FROM 19Z UNTIL 02Z.
THIS ACTIVITY MAY IMPACT THE KRKS AIRPORT DURING THIS TIMEFRAME.

&&

.FIRE WEATHER...

TODAY...HIGH TEMPERATURES WILL BE WARM AND SEASONAL...WITH ANOTHER
ROUND OF ISOLATED TO WIDELY SCATTERED CHANCES FOR MOSTLY LIGHT
SHOWERS OR AN ISOLATED THUNDERSTORM POSSIBLE MAINLY SOUTH OF A
MARBLETON TO KAYCEE LINE. WINDS WILL BEGIN TO INCREASE ONCE AGAIN
MONDAY NIGHT AS WILL CHANCES FOR PRECIPITATION IN THE WESTERN
MOUNTAIN ZONES...AS THE NEXT UPPER LEVEL DISTURBANCE APPROACHES FROM
THE WEST...HERALDING THE BEGINNING OF A COUPLE OF DAYS OF
PRECIPITATION OUT WEST. SIGNIFICANT MOUNTAIN SNOWS WILL BE POSSIBLE
STARTING TUESDAY NIGHT THROUGH WEDNESDAY MORNING. OTHERWISE...WARM
AND MOSTLY DRY ACROSS DISPATCH ZONES EAST OF THE DIVIDE...WITH
SMALL CHANCES FOR ISOLATED SHOWERS AND THUNDERSTORMS THROUGH TUESDAY
EVENING. BREEZY TO WINDY CONDITIONS WILL ALSO COMMENCE ACROSS ALL
ZONES FROM TUESDAY AFTERNOON...LASTING THROUGH THURSDAY MORNING.
AS A RESULT...THERE WILL BE SOME ENHANCED FIRE DANGER...ESPECIALLY
TUESDAY...AS THE WARMEST TEMPERATURES OF THE SEASON COMBINE WITH
THE STRONG WINDS. COOLER TEMPERATURES AND BETTER CHANCES FOR
PRECIPITATION ARE EXPECTED BOTH WEDNESDAY AND THURSDAY...MODERATING
THE DANGER TO SOME EXTENT.

&&

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

$$

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








000
FXUS65 KCYS 200934
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
334 AM MDT SUN APR 20 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)

ISSUED AT 334 AM MDT SUN APR 20 2014

WATER VAPOR IMAGERY FROM EARLY THIS MORNING SHOWS DRIER AIR AND
SUBSIDENCE MOVING OVER THE REGION WITH JUST SOME SCT MID CLOUDS
MOVING OVER THE FORECAST AREA. A FAIRLY STRONG UPPER LEVEL SHORTWAVE
CURRENTLY OVER THE NORTHERN ROCKIES WILL MOVE ACROSS THE US/CANADIAN
BORDER TODAY. THE ATTENDANT PACIFIC COLD FRONT IS CURRENTLY DRAPED
FROM WESTERN MONTANA DOWN INTO NORTHERN NEVADA...AND WILL MOVE
ACROSS THE PLAINS ROUGHLY BETWEEN 18 AND 00Z AND BACK INTO
THE MOUNTAINS THROUGH 06Z. TEMPS WILL INCREASE BACK INTO THE 60S AND
70S AHEAD OF THE FRONT WHILE A WEAK UPPER LEVEL IMPULSE IN ZONAL
FLOW ALOFT APPROACHES FROM THE WEST. THE COMBINATION OF FEATURES
IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND TSTORMS TO THE HIGH
COUNTRY AND ALONG THE CHEYENNE RIDGE LATE IN THE AFTERNOON. THE NAM
AND ECMWF ARE A BIT MORE BULLISH WITH INSTABILITY THIS AFTERNOON VS
THE GFS...WITH LI`S DROPPING TO BETWEEN MINUS 1 AND MINUS 2. BUT
TIMING OF THE FRONT AND SUBSIDENCE AHEAD OF THE DISTURBANCE LOOKS TO
LIMIT CONVECTION ACROSS THE PLAINS. NOT WHOLLY CONVINCE THERE WONT
BE A STRAY SHOWER OR TWO ALONG THE FRONT AS IT TREKS SOUTH ACROSS
THIS AREA...BUT CHANCES ARE LOW ENOUGH TO WILL KEEP MENTION OUT OF
THE FORECAST.

COOLER TEMPS AND WEAK SOUTHEASTERLY RETURN FLOW WILL KEEP CONDITIONS
DRY FOR THE MOST PART ON MONDAY...WITH ONLY A SLIGHT CHANCE FOR RAIN
SHOWERS WITHIN CONVERGENT SFC FLOW DEVELOPING ALONG THE LARAMIE
RANGE. OTHERWISE...MONDAY LOOKS TO BE A FAIRLY CALM AND PLEASANT
DAY. FLOW ALOFT WILL INCREASE AND BACK TO THE SOUTHWEST AHEAD OF A
RATHER STRONG UPPER TROUGH MOVING ACROSS THE GREAT BASIN MONDAY
NIGHT AND TUESDAY. THE LEESIDE PRESSURE TROUGH WILL STRENGTHEN AHEAD
OF THIS WAVE...WITH INCREASING SOUTHERLY SFC FLOW ADVECTING UPPER
30S TO 40S DEW POINTS INTO THE PANHANDLE ON TUESDAY. A PIECE OF
ENERGY EJECTING OUT AHEAD OF THE TROUGH WILL MOVE OVER THE CWA
TUESDAY AFTERNOON WITH 700MB TEMPS INCREASING TO BETWEEN 7 AND 9C.
SO...EXPECT A BROADER COVERAGE OF CONVECTION TO DEVELOP IN THE
AFTERNOON WITH THE COMBINATION OF ENERGY ALOFT...OROGRAPHICS...AND
SFC CONVERGENCE ALONG THE LEESIDE TROUGH. WILL MAINTAIN ONLY SLIGHT
CHANCE TO CHANCE FOR TSTORMS FOR NOW THO AS WAA ALOFT AND POSSIBLE
MIDLEVEL DRY SLOTTING COULD LIMIT OVERALL EXPANSE AND INTENSITY OF
CONVECTION. BUT...WILL HAVE TO WATCH THIS SYSTEM CLOSELY FOR THE
POTENTIAL A FEW STRONGER STORMS MAY DEVELOP ACROSS THE PANHANDLE
WHERE LLVL MOISTURE AND COOLER TEMPS ALOFT WILL BE IN PLACE.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 334 AM MDT SUN APR 20 2014

WINDS CONTINUE TO BE THE MAIN FORECAST CHALLENGE IN THE LONG
TERM...FOLLOWED BY THUNDERSTORM CHANCES.

STARTING OFF TUESDAY NIGHT...LOOKS LIKE WE SHOULD SEE ONGOING
CONVECTION MOVING OUT INTO THE PANHANDLE TUESDAY EVENING. NAM
SHOWING 40 TO LOW 50 DEWPOINTS IN THE PANHANDLE TUESDAY NIGHT. GFS
AND NAM SHOWING FAIRLY WIDESPREAD QPF ENDING AROUND 06Z. WENT
AHEAD WITH CHANCE POPS AS IT REMAINS UNSTABLE OUT THERE THROUGH
THE EVENING HOURS. NAM FORECASTING LIFTED INDICES OF -3 TO -4C. TO
THE WEST...A STRONG SHORTWAVE TRACKS THROUGH WESTERN WYOMING WITH
A COLD FRONT FORECAST TO MOVE JUST WEST OF CARBON COUNTY TUESDAY
EVENING. FAIRLY UNSTABLE CONDITIONS OUT THAT WAY TOO...SO A
COMBINATION OF UNSTABLE AIR AND UPSLOPING CONDITIONS SHOULD GIVE
US FAIRLY GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS.

SHORTWAVE TRACKS INTO EASTERN MONTANA BY 12Z WEDNESDAY. COLD FRONT
LOOKS TO MOVE THROUGH SOUTHEAST WYOMING THROUGH THE DAY WEDNESDAY
WITH 700MB WINDS REALLY RAMPING UP BEHIND THE FRONT. BOTH THE GFS
AND ECMWF SHOWING 700MB WINDS INCREASING TO 45 TO 50KTS BEHIND
THIS FRONT. GUIDANCE HAS BEEN SHOWING THIS HAPPENING FOR SEVERAL
MODEL RUNS NOW...SO CONFIDENCE IS GROWING THAT WE WILL AT LEAST
SEE OUR WIND PRONE AREAS HITTING WARNING CRITERIA WEDNESDAY
AFTERNOON AND MAYBE AS EARLY AS WEDNESDAY MORNING IF THE ECMWF
SOLUTION COMES TRUE.

WINDS REMAIN ELEVATED THURSDAY INTO FRIDAY AS THE GFS AND TO A
LESSER EXTENT THE ECMWF KEEP 700MB WINDS OF 40KTS OR HIGHER. BY
FRIDAY MORNING...A SURFACE LOW MOVES INTO NORTH CENTRAL
WYOMING...EASING THE GRADIENT AND WINDS THROUGH FRIDAY AFTERNOON.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1121 PM MDT SAT APR 19 2014

VFR CONDITIONS EXPECTED AS SOUTHEAST WYOMING AND NORTHERN COLORADO
REMAIN UNDER AN AREA OF HIGH PRESSURE. DO NOT FORESEE ANY WEATHER
IMPACTS TO AVIATION INTERESTS THE NEXT 24 TO 48 HOURS.

&&

.FIRE WEATHER...
ISSUED AT 334 AM MDT SUN APR 20 2014

THIS AFTERNOON WILL SEE A CHANCE FOR SHOWERS AND TSTORMS MAINLY
ALONG AND WEST OF INTERSTATE 25...WITH WETTING RAINS LIKELY FROM
THIS ACTIVITY. HUMIDITY VALUES WILL GENERALLY STAY ABOVE 20
PERCENT DURING THE AFTERNOON HOURS TODAY THROUGH
MIDWEEK...ALTHOUGH HUMIDITIES MAY DROP TO 15 PERCENT ACROSS FAR
WESTERN PORTIONS OF CARBON COUNTY ON MONDAY. GOOD RECOVERIES ARE
EXPECTED AT NIGHT. ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS IS
POSSIBLE ON TUESDAY...WITH GUSTY WINDS LIKELY TUESDAY AND
WEDNESDAY.

&&

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

$$

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








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000
FXUS63 KUNR 200906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
306 AM MDT SUN APR 20 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 305 AM MDT SUN APR 20 2014

CURRENT SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
CENTRAL AND EASTERN DAKOTAS. AN AREA OF LOW PRESSURE IS LOCATED
OVER SOUTHERN AB...WITH WEAK COLD FRONT STRETCHING SOUTH-SOUTHWEST
ACROSS WESTERN MT INTO EASTERN ID. LEE TROF STRETCHES SOUTHEAST
INTO EASTERN WY. UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE
NORTHERN HIGH PLAINS...WITH SHORTWAVE TROF MOVING QUICKLY EAST
ACROSS THE NORTHERN ROCKIES. SKIES ARE MAINLY CLEAR ACROSS THE
AREA WITH TEMPS MOSTLY IN THE MID 30S TO MID 40S. WINDS ARE SOUTH
TO SOUTHEAST ACROSS MOST OF THE AREA NOW.

WARM AND MAINLY DRY WX WILL CONTINUE FOR TODAY AND INTO EARLY THIS
WEEK AS NEAR ZONAL FLOW ALOFT PERSISTS. FOR TODAY...SKIES WILL BE
MOSTLY SUNNY IN GENERAL...ESPECIALLY THROUGH THE MIDDAY HOURS.
CLOUDS WILL INCREASE SOME IN THE AFTERNOON AS THE COLD FRONT
ARRIVES...ESPECIALLY ACROSS SOUTHERN AREAS. HIGHS WILL MOSTLY BE IN
THE 70S...WITH 60S OVER THE BLACK HILLS AND PORTIONS OF NORTHEAST
WY. THE FRONT WILL MAKE ITS WAY INTO WESTERN PORTIONS OF THE CWA BY
18Z AND ACROSS THE REST OF THE CWA DURING THE AFTERNOON AND EARLY
EVENING. BRISK NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE PLAINS
BEHIND THE FRONT THIS AFTERNOON AND EVENING.

AHEAD OF THE FRONT...SOUTHERLY WINDS WILL HELP TO BRING INCREASING
LOW LEVEL MOISTURE THROUGH THE DAY...ESPECIALLY TO THE EAST OF THE
BLACK HILLS...WHERE DEWPOINTS SHOULD RISE INTO THE 40S THIS
AFTERNOON. THIS MOISTURE...COMBINED WITH STRONG WARMING AND STEEP
LAPSE RATES THIS AFTERNOON...WILL HELP TO PRODUCE CAPE VALUES LIKELY
EXCEEDING 500 J/KG OVER SOUTH CENTRAL SD BY LATE IN THE DAY. THE
FRONT WILL ARRIVE IN THIS AREA LATE IN THE DAY...WITH AT LEAST
ISOLATED SHOWERS AND STORMS EXPECTED TO DEVELOP LATE IN THE
AFTERNOON AND EARLY EVENING. A STRONGER STORM OR TWO LOOKS POSSIBLE
WITH GUSTY WINDS AND AT LEAST THE POTENTIAL FOR SMALL HAIL. ANY
ACTIVITY SHOULD PUSH EAST OF SOUTH CENTRAL SD BY LATE EVENING.

AS TODAYS WEATHER WILL BE SIMILAR TO WHAT HAPPENED FRIDAY...MONDAY
WILL BE MUCH LIKE YESTERDAY...WITH MOSTLY SUNNY SKIES...MILD
TEMPERATURES...AND RELATIVELY LIGHT WINDS. NORTHWESTERLY WINDS CAN
BE EXPECTED TO THE NORTH AND EAST OF THE BLACK HILLS...WITH WINDS
TURNING SOUTHERLY OVER NORTHEAST WY AND THE BLACK HILLS. HIGHS WILL
BE IN THE 60S AND LOWER 70S. LOWS MONDAY NIGHT WILL GENERALLY BE IN
THE MID 30S TO MID 40S...WITH SOUTH TO SOUTHEAST WINDS DEVELOPING
OVER THE ENTIRE AREA.

&&

.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 305 AM MDT SUN APR 20 2014

MODELS ARE IN PRETTY GOOD AGREEMENT FOR MEDIUM RANGE. AN UPPER
LEVEL TROUGH ENTERING THE NORTHWEST US COAST EARLY TUESDAY WILL
MOVE ACROSS THE ROCKIES INTO THE NORTHERN PLAINS BY THURSDAY
MORNING.

AHEAD OF IT ON TUESDAY...LOW PRESSURE WILL DEVELOP OVER MT WITH WELL
DEFINED PRESSURE FALLS AND SUBSEQUENT WINDY SOUTHERLY RETURN FLOW.
LOW MOVES INTO SOUTHEAST MT WITH TROUGH PIVOTING NORTHEAST INTO
NORTHEAST WY/WESTERN SD. A FEW -TSRA MAY DEVELOP ALONG/AHEAD OF THIS
BOUNDARY. 0-6KM SHEAR SUFFICIENT FOR STRONG STORMS...BUT MOISTURE
AVAILABILITY IN QUESTION GIVEN AMOUNT OF MIXING AS TEMPERATURES
CLIMB WELL INTO THE 70S.

WEDNESDAY...INITIAL LOW PRESSURE MOVES EAST OF CWA AS SECONDARY LOW
DEVELOPS OVER MT/SK BORDER AS UPPER LOW WRAPS UP OVER THE SAME AREA.
THIS WILL PUSH DRIER AIR INTO CWA EARLY...BUT MOISTURE WILL RETURN
LATER IN THE DAY/NIGHT AS WRAP AROUND SHIFTS SOUTH FROM MT/ND.
TEMPERATURES WILL BE QUITE WARM GIVEN FORECAST SOUNDINGS WITH WEAK
INSTABILITY SUPPORTIVE OF DIURNAL -TSRA. AS PRECIPITATION TRENDS TO
-SHRA WEDNESDAY NIGHT...A FEW -SHSN POSSIBLE IN THE HIGHER
ELEVATIONS GIVEN WET BULB PROFILES.

THURSDAY...UPPER/SURFACE LOW SHIFTS EAST INTO THE UPPER MIDWEST
LEAVING BACKWASH PRECIPITATION ACROSS THE CWA AS WELL AS A RATHER
TIGHT PRESSURE GRADIENT. HAVE PAINTED VERY WINDY CONDITIONS...BUT
COULD EASILY BE IN THE STRONG CATEGORY GIVEN CYCLONIC FLOW/COLD AIR
ADVECTION. COLD ENOUGH FOR -SHRASN THURSDAY NIGHT...EVEN ON THE
PLAINS OF NORTHEAST WY/NORTHWEST SD. TEMPERATURES WILL BE NOTICEABLY
COLDER.

FOR FRIDAY...LULL IN THE WEATHER EXPECTED AS UPPER LEVEL RIDGE POKES
INTO THE CWA. LOOKING AHEAD TO NEXT WEEKEND...GFS/ECMWF BRING
ANOTHER STORM SYSTEM/UPPER LOW INTO THE AREA...BUT THIS TIME MOVING
IT FROM THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS. MODELS HAVE
TRENDED WETTER WITH THIS SYSTEM...BUT TOO FAR OUT TO ASCERTAIN
EFFECT ON SENSIBLE WEATHER. WILL HAVE NORMAL CHANCE POPS IN THERE
FOR NOW.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 305 AM MDT SUN APR 20 2014

A WEAK COLD FRONT WILL PASS THROUGH THE AREA TODAY. AHEAD OF
IT...SOUTHERLY WINDS ARE EXPECTED. BEHIND IT...WINDS WILL SHIFT TO
A NORTHERLY DIRECTION AND BECOME GUSTY AT TIMES. ISOLATED -TSRA
ARE POSSIBLE OVER SOUTH CENTRAL SD LATE THIS AFTERNOON/EARLY THIS
EVENING WITH LOCAL MVFR VSBYS/GUSTY WINDS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON







000
FXUS63 KUNR 200906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
306 AM MDT SUN APR 20 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 305 AM MDT SUN APR 20 2014

CURRENT SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
CENTRAL AND EASTERN DAKOTAS. AN AREA OF LOW PRESSURE IS LOCATED
OVER SOUTHERN AB...WITH WEAK COLD FRONT STRETCHING SOUTH-SOUTHWEST
ACROSS WESTERN MT INTO EASTERN ID. LEE TROF STRETCHES SOUTHEAST
INTO EASTERN WY. UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE
NORTHERN HIGH PLAINS...WITH SHORTWAVE TROF MOVING QUICKLY EAST
ACROSS THE NORTHERN ROCKIES. SKIES ARE MAINLY CLEAR ACROSS THE
AREA WITH TEMPS MOSTLY IN THE MID 30S TO MID 40S. WINDS ARE SOUTH
TO SOUTHEAST ACROSS MOST OF THE AREA NOW.

WARM AND MAINLY DRY WX WILL CONTINUE FOR TODAY AND INTO EARLY THIS
WEEK AS NEAR ZONAL FLOW ALOFT PERSISTS. FOR TODAY...SKIES WILL BE
MOSTLY SUNNY IN GENERAL...ESPECIALLY THROUGH THE MIDDAY HOURS.
CLOUDS WILL INCREASE SOME IN THE AFTERNOON AS THE COLD FRONT
ARRIVES...ESPECIALLY ACROSS SOUTHERN AREAS. HIGHS WILL MOSTLY BE IN
THE 70S...WITH 60S OVER THE BLACK HILLS AND PORTIONS OF NORTHEAST
WY. THE FRONT WILL MAKE ITS WAY INTO WESTERN PORTIONS OF THE CWA BY
18Z AND ACROSS THE REST OF THE CWA DURING THE AFTERNOON AND EARLY
EVENING. BRISK NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE PLAINS
BEHIND THE FRONT THIS AFTERNOON AND EVENING.

AHEAD OF THE FRONT...SOUTHERLY WINDS WILL HELP TO BRING INCREASING
LOW LEVEL MOISTURE THROUGH THE DAY...ESPECIALLY TO THE EAST OF THE
BLACK HILLS...WHERE DEWPOINTS SHOULD RISE INTO THE 40S THIS
AFTERNOON. THIS MOISTURE...COMBINED WITH STRONG WARMING AND STEEP
LAPSE RATES THIS AFTERNOON...WILL HELP TO PRODUCE CAPE VALUES LIKELY
EXCEEDING 500 J/KG OVER SOUTH CENTRAL SD BY LATE IN THE DAY. THE
FRONT WILL ARRIVE IN THIS AREA LATE IN THE DAY...WITH AT LEAST
ISOLATED SHOWERS AND STORMS EXPECTED TO DEVELOP LATE IN THE
AFTERNOON AND EARLY EVENING. A STRONGER STORM OR TWO LOOKS POSSIBLE
WITH GUSTY WINDS AND AT LEAST THE POTENTIAL FOR SMALL HAIL. ANY
ACTIVITY SHOULD PUSH EAST OF SOUTH CENTRAL SD BY LATE EVENING.

AS TODAYS WEATHER WILL BE SIMILAR TO WHAT HAPPENED FRIDAY...MONDAY
WILL BE MUCH LIKE YESTERDAY...WITH MOSTLY SUNNY SKIES...MILD
TEMPERATURES...AND RELATIVELY LIGHT WINDS. NORTHWESTERLY WINDS CAN
BE EXPECTED TO THE NORTH AND EAST OF THE BLACK HILLS...WITH WINDS
TURNING SOUTHERLY OVER NORTHEAST WY AND THE BLACK HILLS. HIGHS WILL
BE IN THE 60S AND LOWER 70S. LOWS MONDAY NIGHT WILL GENERALLY BE IN
THE MID 30S TO MID 40S...WITH SOUTH TO SOUTHEAST WINDS DEVELOPING
OVER THE ENTIRE AREA.

&&

.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 305 AM MDT SUN APR 20 2014

MODELS ARE IN PRETTY GOOD AGREEMENT FOR MEDIUM RANGE. AN UPPER
LEVEL TROUGH ENTERING THE NORTHWEST US COAST EARLY TUESDAY WILL
MOVE ACROSS THE ROCKIES INTO THE NORTHERN PLAINS BY THURSDAY
MORNING.

AHEAD OF IT ON TUESDAY...LOW PRESSURE WILL DEVELOP OVER MT WITH WELL
DEFINED PRESSURE FALLS AND SUBSEQUENT WINDY SOUTHERLY RETURN FLOW.
LOW MOVES INTO SOUTHEAST MT WITH TROUGH PIVOTING NORTHEAST INTO
NORTHEAST WY/WESTERN SD. A FEW -TSRA MAY DEVELOP ALONG/AHEAD OF THIS
BOUNDARY. 0-6KM SHEAR SUFFICIENT FOR STRONG STORMS...BUT MOISTURE
AVAILABILITY IN QUESTION GIVEN AMOUNT OF MIXING AS TEMPERATURES
CLIMB WELL INTO THE 70S.

WEDNESDAY...INITIAL LOW PRESSURE MOVES EAST OF CWA AS SECONDARY LOW
DEVELOPS OVER MT/SK BORDER AS UPPER LOW WRAPS UP OVER THE SAME AREA.
THIS WILL PUSH DRIER AIR INTO CWA EARLY...BUT MOISTURE WILL RETURN
LATER IN THE DAY/NIGHT AS WRAP AROUND SHIFTS SOUTH FROM MT/ND.
TEMPERATURES WILL BE QUITE WARM GIVEN FORECAST SOUNDINGS WITH WEAK
INSTABILITY SUPPORTIVE OF DIURNAL -TSRA. AS PRECIPITATION TRENDS TO
-SHRA WEDNESDAY NIGHT...A FEW -SHSN POSSIBLE IN THE HIGHER
ELEVATIONS GIVEN WET BULB PROFILES.

THURSDAY...UPPER/SURFACE LOW SHIFTS EAST INTO THE UPPER MIDWEST
LEAVING BACKWASH PRECIPITATION ACROSS THE CWA AS WELL AS A RATHER
TIGHT PRESSURE GRADIENT. HAVE PAINTED VERY WINDY CONDITIONS...BUT
COULD EASILY BE IN THE STRONG CATEGORY GIVEN CYCLONIC FLOW/COLD AIR
ADVECTION. COLD ENOUGH FOR -SHRASN THURSDAY NIGHT...EVEN ON THE
PLAINS OF NORTHEAST WY/NORTHWEST SD. TEMPERATURES WILL BE NOTICEABLY
COLDER.

FOR FRIDAY...LULL IN THE WEATHER EXPECTED AS UPPER LEVEL RIDGE POKES
INTO THE CWA. LOOKING AHEAD TO NEXT WEEKEND...GFS/ECMWF BRING
ANOTHER STORM SYSTEM/UPPER LOW INTO THE AREA...BUT THIS TIME MOVING
IT FROM THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS. MODELS HAVE
TRENDED WETTER WITH THIS SYSTEM...BUT TOO FAR OUT TO ASCERTAIN
EFFECT ON SENSIBLE WEATHER. WILL HAVE NORMAL CHANCE POPS IN THERE
FOR NOW.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 305 AM MDT SUN APR 20 2014

A WEAK COLD FRONT WILL PASS THROUGH THE AREA TODAY. AHEAD OF
IT...SOUTHERLY WINDS ARE EXPECTED. BEHIND IT...WINDS WILL SHIFT TO
A NORTHERLY DIRECTION AND BECOME GUSTY AT TIMES. ISOLATED -TSRA
ARE POSSIBLE OVER SOUTH CENTRAL SD LATE THIS AFTERNOON/EARLY THIS
EVENING WITH LOCAL MVFR VSBYS/GUSTY WINDS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON







000
FXUS63 KUNR 200906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
306 AM MDT SUN APR 20 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 305 AM MDT SUN APR 20 2014

CURRENT SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
CENTRAL AND EASTERN DAKOTAS. AN AREA OF LOW PRESSURE IS LOCATED
OVER SOUTHERN AB...WITH WEAK COLD FRONT STRETCHING SOUTH-SOUTHWEST
ACROSS WESTERN MT INTO EASTERN ID. LEE TROF STRETCHES SOUTHEAST
INTO EASTERN WY. UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE
NORTHERN HIGH PLAINS...WITH SHORTWAVE TROF MOVING QUICKLY EAST
ACROSS THE NORTHERN ROCKIES. SKIES ARE MAINLY CLEAR ACROSS THE
AREA WITH TEMPS MOSTLY IN THE MID 30S TO MID 40S. WINDS ARE SOUTH
TO SOUTHEAST ACROSS MOST OF THE AREA NOW.

WARM AND MAINLY DRY WX WILL CONTINUE FOR TODAY AND INTO EARLY THIS
WEEK AS NEAR ZONAL FLOW ALOFT PERSISTS. FOR TODAY...SKIES WILL BE
MOSTLY SUNNY IN GENERAL...ESPECIALLY THROUGH THE MIDDAY HOURS.
CLOUDS WILL INCREASE SOME IN THE AFTERNOON AS THE COLD FRONT
ARRIVES...ESPECIALLY ACROSS SOUTHERN AREAS. HIGHS WILL MOSTLY BE IN
THE 70S...WITH 60S OVER THE BLACK HILLS AND PORTIONS OF NORTHEAST
WY. THE FRONT WILL MAKE ITS WAY INTO WESTERN PORTIONS OF THE CWA BY
18Z AND ACROSS THE REST OF THE CWA DURING THE AFTERNOON AND EARLY
EVENING. BRISK NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE PLAINS
BEHIND THE FRONT THIS AFTERNOON AND EVENING.

AHEAD OF THE FRONT...SOUTHERLY WINDS WILL HELP TO BRING INCREASING
LOW LEVEL MOISTURE THROUGH THE DAY...ESPECIALLY TO THE EAST OF THE
BLACK HILLS...WHERE DEWPOINTS SHOULD RISE INTO THE 40S THIS
AFTERNOON. THIS MOISTURE...COMBINED WITH STRONG WARMING AND STEEP
LAPSE RATES THIS AFTERNOON...WILL HELP TO PRODUCE CAPE VALUES LIKELY
EXCEEDING 500 J/KG OVER SOUTH CENTRAL SD BY LATE IN THE DAY. THE
FRONT WILL ARRIVE IN THIS AREA LATE IN THE DAY...WITH AT LEAST
ISOLATED SHOWERS AND STORMS EXPECTED TO DEVELOP LATE IN THE
AFTERNOON AND EARLY EVENING. A STRONGER STORM OR TWO LOOKS POSSIBLE
WITH GUSTY WINDS AND AT LEAST THE POTENTIAL FOR SMALL HAIL. ANY
ACTIVITY SHOULD PUSH EAST OF SOUTH CENTRAL SD BY LATE EVENING.

AS TODAYS WEATHER WILL BE SIMILAR TO WHAT HAPPENED FRIDAY...MONDAY
WILL BE MUCH LIKE YESTERDAY...WITH MOSTLY SUNNY SKIES...MILD
TEMPERATURES...AND RELATIVELY LIGHT WINDS. NORTHWESTERLY WINDS CAN
BE EXPECTED TO THE NORTH AND EAST OF THE BLACK HILLS...WITH WINDS
TURNING SOUTHERLY OVER NORTHEAST WY AND THE BLACK HILLS. HIGHS WILL
BE IN THE 60S AND LOWER 70S. LOWS MONDAY NIGHT WILL GENERALLY BE IN
THE MID 30S TO MID 40S...WITH SOUTH TO SOUTHEAST WINDS DEVELOPING
OVER THE ENTIRE AREA.

&&

.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 305 AM MDT SUN APR 20 2014

MODELS ARE IN PRETTY GOOD AGREEMENT FOR MEDIUM RANGE. AN UPPER
LEVEL TROUGH ENTERING THE NORTHWEST US COAST EARLY TUESDAY WILL
MOVE ACROSS THE ROCKIES INTO THE NORTHERN PLAINS BY THURSDAY
MORNING.

AHEAD OF IT ON TUESDAY...LOW PRESSURE WILL DEVELOP OVER MT WITH WELL
DEFINED PRESSURE FALLS AND SUBSEQUENT WINDY SOUTHERLY RETURN FLOW.
LOW MOVES INTO SOUTHEAST MT WITH TROUGH PIVOTING NORTHEAST INTO
NORTHEAST WY/WESTERN SD. A FEW -TSRA MAY DEVELOP ALONG/AHEAD OF THIS
BOUNDARY. 0-6KM SHEAR SUFFICIENT FOR STRONG STORMS...BUT MOISTURE
AVAILABILITY IN QUESTION GIVEN AMOUNT OF MIXING AS TEMPERATURES
CLIMB WELL INTO THE 70S.

WEDNESDAY...INITIAL LOW PRESSURE MOVES EAST OF CWA AS SECONDARY LOW
DEVELOPS OVER MT/SK BORDER AS UPPER LOW WRAPS UP OVER THE SAME AREA.
THIS WILL PUSH DRIER AIR INTO CWA EARLY...BUT MOISTURE WILL RETURN
LATER IN THE DAY/NIGHT AS WRAP AROUND SHIFTS SOUTH FROM MT/ND.
TEMPERATURES WILL BE QUITE WARM GIVEN FORECAST SOUNDINGS WITH WEAK
INSTABILITY SUPPORTIVE OF DIURNAL -TSRA. AS PRECIPITATION TRENDS TO
-SHRA WEDNESDAY NIGHT...A FEW -SHSN POSSIBLE IN THE HIGHER
ELEVATIONS GIVEN WET BULB PROFILES.

THURSDAY...UPPER/SURFACE LOW SHIFTS EAST INTO THE UPPER MIDWEST
LEAVING BACKWASH PRECIPITATION ACROSS THE CWA AS WELL AS A RATHER
TIGHT PRESSURE GRADIENT. HAVE PAINTED VERY WINDY CONDITIONS...BUT
COULD EASILY BE IN THE STRONG CATEGORY GIVEN CYCLONIC FLOW/COLD AIR
ADVECTION. COLD ENOUGH FOR -SHRASN THURSDAY NIGHT...EVEN ON THE
PLAINS OF NORTHEAST WY/NORTHWEST SD. TEMPERATURES WILL BE NOTICEABLY
COLDER.

FOR FRIDAY...LULL IN THE WEATHER EXPECTED AS UPPER LEVEL RIDGE POKES
INTO THE CWA. LOOKING AHEAD TO NEXT WEEKEND...GFS/ECMWF BRING
ANOTHER STORM SYSTEM/UPPER LOW INTO THE AREA...BUT THIS TIME MOVING
IT FROM THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS. MODELS HAVE
TRENDED WETTER WITH THIS SYSTEM...BUT TOO FAR OUT TO ASCERTAIN
EFFECT ON SENSIBLE WEATHER. WILL HAVE NORMAL CHANCE POPS IN THERE
FOR NOW.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 305 AM MDT SUN APR 20 2014

A WEAK COLD FRONT WILL PASS THROUGH THE AREA TODAY. AHEAD OF
IT...SOUTHERLY WINDS ARE EXPECTED. BEHIND IT...WINDS WILL SHIFT TO
A NORTHERLY DIRECTION AND BECOME GUSTY AT TIMES. ISOLATED -TSRA
ARE POSSIBLE OVER SOUTH CENTRAL SD LATE THIS AFTERNOON/EARLY THIS
EVENING WITH LOCAL MVFR VSBYS/GUSTY WINDS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON







000
FXUS63 KUNR 200906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
306 AM MDT SUN APR 20 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 305 AM MDT SUN APR 20 2014

CURRENT SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
CENTRAL AND EASTERN DAKOTAS. AN AREA OF LOW PRESSURE IS LOCATED
OVER SOUTHERN AB...WITH WEAK COLD FRONT STRETCHING SOUTH-SOUTHWEST
ACROSS WESTERN MT INTO EASTERN ID. LEE TROF STRETCHES SOUTHEAST
INTO EASTERN WY. UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE
NORTHERN HIGH PLAINS...WITH SHORTWAVE TROF MOVING QUICKLY EAST
ACROSS THE NORTHERN ROCKIES. SKIES ARE MAINLY CLEAR ACROSS THE
AREA WITH TEMPS MOSTLY IN THE MID 30S TO MID 40S. WINDS ARE SOUTH
TO SOUTHEAST ACROSS MOST OF THE AREA NOW.

WARM AND MAINLY DRY WX WILL CONTINUE FOR TODAY AND INTO EARLY THIS
WEEK AS NEAR ZONAL FLOW ALOFT PERSISTS. FOR TODAY...SKIES WILL BE
MOSTLY SUNNY IN GENERAL...ESPECIALLY THROUGH THE MIDDAY HOURS.
CLOUDS WILL INCREASE SOME IN THE AFTERNOON AS THE COLD FRONT
ARRIVES...ESPECIALLY ACROSS SOUTHERN AREAS. HIGHS WILL MOSTLY BE IN
THE 70S...WITH 60S OVER THE BLACK HILLS AND PORTIONS OF NORTHEAST
WY. THE FRONT WILL MAKE ITS WAY INTO WESTERN PORTIONS OF THE CWA BY
18Z AND ACROSS THE REST OF THE CWA DURING THE AFTERNOON AND EARLY
EVENING. BRISK NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE PLAINS
BEHIND THE FRONT THIS AFTERNOON AND EVENING.

AHEAD OF THE FRONT...SOUTHERLY WINDS WILL HELP TO BRING INCREASING
LOW LEVEL MOISTURE THROUGH THE DAY...ESPECIALLY TO THE EAST OF THE
BLACK HILLS...WHERE DEWPOINTS SHOULD RISE INTO THE 40S THIS
AFTERNOON. THIS MOISTURE...COMBINED WITH STRONG WARMING AND STEEP
LAPSE RATES THIS AFTERNOON...WILL HELP TO PRODUCE CAPE VALUES LIKELY
EXCEEDING 500 J/KG OVER SOUTH CENTRAL SD BY LATE IN THE DAY. THE
FRONT WILL ARRIVE IN THIS AREA LATE IN THE DAY...WITH AT LEAST
ISOLATED SHOWERS AND STORMS EXPECTED TO DEVELOP LATE IN THE
AFTERNOON AND EARLY EVENING. A STRONGER STORM OR TWO LOOKS POSSIBLE
WITH GUSTY WINDS AND AT LEAST THE POTENTIAL FOR SMALL HAIL. ANY
ACTIVITY SHOULD PUSH EAST OF SOUTH CENTRAL SD BY LATE EVENING.

AS TODAYS WEATHER WILL BE SIMILAR TO WHAT HAPPENED FRIDAY...MONDAY
WILL BE MUCH LIKE YESTERDAY...WITH MOSTLY SUNNY SKIES...MILD
TEMPERATURES...AND RELATIVELY LIGHT WINDS. NORTHWESTERLY WINDS CAN
BE EXPECTED TO THE NORTH AND EAST OF THE BLACK HILLS...WITH WINDS
TURNING SOUTHERLY OVER NORTHEAST WY AND THE BLACK HILLS. HIGHS WILL
BE IN THE 60S AND LOWER 70S. LOWS MONDAY NIGHT WILL GENERALLY BE IN
THE MID 30S TO MID 40S...WITH SOUTH TO SOUTHEAST WINDS DEVELOPING
OVER THE ENTIRE AREA.

&&

.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 305 AM MDT SUN APR 20 2014

MODELS ARE IN PRETTY GOOD AGREEMENT FOR MEDIUM RANGE. AN UPPER
LEVEL TROUGH ENTERING THE NORTHWEST US COAST EARLY TUESDAY WILL
MOVE ACROSS THE ROCKIES INTO THE NORTHERN PLAINS BY THURSDAY
MORNING.

AHEAD OF IT ON TUESDAY...LOW PRESSURE WILL DEVELOP OVER MT WITH WELL
DEFINED PRESSURE FALLS AND SUBSEQUENT WINDY SOUTHERLY RETURN FLOW.
LOW MOVES INTO SOUTHEAST MT WITH TROUGH PIVOTING NORTHEAST INTO
NORTHEAST WY/WESTERN SD. A FEW -TSRA MAY DEVELOP ALONG/AHEAD OF THIS
BOUNDARY. 0-6KM SHEAR SUFFICIENT FOR STRONG STORMS...BUT MOISTURE
AVAILABILITY IN QUESTION GIVEN AMOUNT OF MIXING AS TEMPERATURES
CLIMB WELL INTO THE 70S.

WEDNESDAY...INITIAL LOW PRESSURE MOVES EAST OF CWA AS SECONDARY LOW
DEVELOPS OVER MT/SK BORDER AS UPPER LOW WRAPS UP OVER THE SAME AREA.
THIS WILL PUSH DRIER AIR INTO CWA EARLY...BUT MOISTURE WILL RETURN
LATER IN THE DAY/NIGHT AS WRAP AROUND SHIFTS SOUTH FROM MT/ND.
TEMPERATURES WILL BE QUITE WARM GIVEN FORECAST SOUNDINGS WITH WEAK
INSTABILITY SUPPORTIVE OF DIURNAL -TSRA. AS PRECIPITATION TRENDS TO
-SHRA WEDNESDAY NIGHT...A FEW -SHSN POSSIBLE IN THE HIGHER
ELEVATIONS GIVEN WET BULB PROFILES.

THURSDAY...UPPER/SURFACE LOW SHIFTS EAST INTO THE UPPER MIDWEST
LEAVING BACKWASH PRECIPITATION ACROSS THE CWA AS WELL AS A RATHER
TIGHT PRESSURE GRADIENT. HAVE PAINTED VERY WINDY CONDITIONS...BUT
COULD EASILY BE IN THE STRONG CATEGORY GIVEN CYCLONIC FLOW/COLD AIR
ADVECTION. COLD ENOUGH FOR -SHRASN THURSDAY NIGHT...EVEN ON THE
PLAINS OF NORTHEAST WY/NORTHWEST SD. TEMPERATURES WILL BE NOTICEABLY
COLDER.

FOR FRIDAY...LULL IN THE WEATHER EXPECTED AS UPPER LEVEL RIDGE POKES
INTO THE CWA. LOOKING AHEAD TO NEXT WEEKEND...GFS/ECMWF BRING
ANOTHER STORM SYSTEM/UPPER LOW INTO THE AREA...BUT THIS TIME MOVING
IT FROM THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS. MODELS HAVE
TRENDED WETTER WITH THIS SYSTEM...BUT TOO FAR OUT TO ASCERTAIN
EFFECT ON SENSIBLE WEATHER. WILL HAVE NORMAL CHANCE POPS IN THERE
FOR NOW.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 305 AM MDT SUN APR 20 2014

A WEAK COLD FRONT WILL PASS THROUGH THE AREA TODAY. AHEAD OF
IT...SOUTHERLY WINDS ARE EXPECTED. BEHIND IT...WINDS WILL SHIFT TO
A NORTHERLY DIRECTION AND BECOME GUSTY AT TIMES. ISOLATED -TSRA
ARE POSSIBLE OVER SOUTH CENTRAL SD LATE THIS AFTERNOON/EARLY THIS
EVENING WITH LOCAL MVFR VSBYS/GUSTY WINDS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON







000
FXUS63 KUNR 200535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1134 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON WITH LCL MVFR VSBY AND GUSTY WINDS.

&&

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

$$

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






000
FXUS63 KUNR 200535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1134 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON WITH LCL MVFR VSBY AND GUSTY WINDS.

&&

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

$$

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






000
FXUS63 KUNR 200535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1134 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON WITH LCL MVFR VSBY AND GUSTY WINDS.

&&

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

$$

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






000
FXUS63 KUNR 200535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1134 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON WITH LCL MVFR VSBY AND GUSTY WINDS.

&&

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

$$

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






000
FXUS65 KRIW 200531
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1131 PM MDT SAT APR 19 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY (ISSUED AT 156 PM MDT)

WEAK SHORTWAVE MOVED INTO THE SW THIS MORNING WITH ACCAS AND
SPRINKLES. THIS AREA HAS NOW TURNED INTO LIGHT SHOWERS AND IS
MERGING WITH OUR MOISTURE...LEFTOVER FRONTAL BOUNDARY AND DAYTIME
HEATING TO PRODUCING SOME BUILDING CUMULUS OVER SWEETWATER COUNTY.
IDEA OF MAINLY ISOLATED SHOWERS AND A COUPLE THUNDERSTORMS IS
LOOKING GOOD WITH A FEW MORE OVER THE MOUNTAINS. COUPLE LIGHTNING
STRIKES JUST SOUTH OF THE BORDER SO FAR. NEXT SYSTEM MOVES EWD
AWAY FROM THE UPPER LOW OFF THE B.C. COAST WHICH PUSHES A COLD
FRONT SE ACROSS THE AREA ON EASTER. THE FRONT MAY INTERACT WITH
THE LEFTOVER MOISTURE FROM TODAY`S SYSTEM OVER OUR FAR SERN ZONES
TO PROVIDE ANOTHER DAY OF MAINLY ISOLATED SHOWERS AND PERHAPS A
THUNDERSTORM OR TWO. INSTABILITY LOOKS VERY LIMITED ON
FORECAST/INTERPOLATED SOUNDINGS. OTHERWISE...ANOTHER MILD DAY
WITH TEMPERATURES GENERALLY 60S EAST OF THE DIVIDE AND 50S TO
LOWER 60S WEST. THE MOUNTAINS WILL BE IN THE 40S AND 50S. RIDGE
AXIS MOVES OVERHEAD ON MONDAY WITH SLIGHTLY WARMER TEMPERATURES
YET. COULD BE A FEW SHOWERS TRYING TO DEVELOP OVER THE FAR WEST BY
MONDAY EVENING AS SOME MOISTURE FROM THE ERN FRINGES OF OUR BIG
MIDWEEK SYSTEM WORKS ON A WARM TEMPERATURES MONDAY.
OTHERWISE...MONDAY LOOKS DRY AND MILD TO WARM. TUESDAY WE STILL
OUR BIG NEGATIVELY TILTED UPPER LOW MOVE INTO THE GREAT BASIN WITH
RAPIDLY FALLING PRESSURES AS A SURFACE LOW FORMS OVER MONTANA.
STRONG SLY FLOW WHICH WILL DEVELOP MONDAY NIGHT WILL CONTINUE TO
STRENGTHEN THROUGH THE DAY TUESDAY LEADING TO A WINDY TO VERY
WINDY DAY FOR MOST EVERYONE. COLD FRONT NEAR THE FAR WEST LATE IN
THE DAY WITH A LINE OF SHOWERS AND THUNDERSTORMS QUITE LIKELY OUT
WEST. A FEW OF THESE COULD BE QUITE STRONG EVEN IF IT`S JUST
SHOWERS AND OR THUNDERSTORMS MOVING NWD AND ADDING TO THE AMBIENT
STRONG SLY FLOW PRODUCING VERY STRONG SLY WINDS. EAST OF THE
DIVIDE...DAYTIME HEATING MAY BE ENOUGH FOR ISOLATED SHOWERS AND
THUNDERSTORMS WITH SOME RETURN FLOW MOISTURE AND HIGHER CAPES
POSSIBLE IN JOHNSON COUNTY. OTHERWISE...WARM AND WINDY WITH PCPN
BECOMING FAIRLY WIDESPREAD OUT WEST. SNOW LEVELS WILL BE ABOVE 10K
FEET DURING THE DAY ADDING TO THE RISK OF SOME MODERATE TO LOCALLY
HEAVY RAIN ON DEEP SNOWPACK.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

A VIGOROUS SHORTWAVE TRACKING NORTHEAST AROUND THE BASE OF THE DEEP
TROUGH THAT WILL BE SITUATED ALONG THE CANADIAN/PACIFIC NORTHWEST
COAST TUE NT WILL PRODUCE NUMEROUS RAIN AND SNOW SHOWERS IN THE FAR
WEST TUESDAY NIGHT WITH 2 TO 3 INCHES OF ACCUMULATING SNOW AFTER
MIDNIGHT IN THE FAR WEST. SOME ISOLATED THUNDER ALSO POSSIBLE.
PRECIPITATION WILL SPILL OVER TO AREAS EAST OF THE DIVIDE LATER
TUESDAY NIGHT AND INTO WEDNESDAY. WEDNESDAY WILL FEATURE PRECIP
MAINLY IN THE FORM OF RAIN EXCEPT MOSTLY SNOW IN THE MOUNTAINS. BY
WEDNESDAY...THE AFOREMENTIONED TROUGH WILL CLOSE INTO AN ALMOST
VERTICALLY STACKED LOW OVER MONTANA AS IT TRACKS EAST. HIGH TEMPS
WED SHOULD RUN ABOUT 10 TO 20 DEGREES COOLER COMPARED TO TUE.THERE
WILL BE MORE PRECIP ACROSS THE NORTH HALF OF THE CWA WEDNESDAY NIGHT
CLOSER TO THE TRACK OF THE LOW. DURING THE COURSE OF THE NIGHT
WEDNESDAY NIGHT...H7 TEMPS WILL DROP TO -10C WEST OF THE DIVIDE AND
-8C EAST SO THAT BY 06Z THU...MOST OF WHAT PRECIP OCCURS WILL BE IN
THE FORM OF SNOWFALL. BY WEDNESDAY NIGHT...WITH ENOUGH COLD AIR
ALOFT DESTABILIZING THE ATMOSPHERE...EXPECT CONVECTIVE SNOW BANDS TO
FORM OFF SOUTH PASS...THE OWL CREEK/BRIDGER MTNS AND THE BIG HORN
MTNS IN THE FAVORABLE NORTHWEST FLOW...WITH THESE SNOW BANDS LIKELY
EXTENDING INTO THE LOWER ELEVATIONS OF EASTERN FREMONT...NATRONA AND
JOHNSON COUNTIES AS WELL AS GREATER CASPER. THE ECMWF IS SLOWER THAN
THE GFS WITH THIS TROUGH SO KEPT THE TIMING OF THE PRECIP THE SAME
WHICH IS A BLEND OF THE SPEED OF THE TWO MODELS. SNOWFALL WILL TAPER
OFF THURSDAY MORNING. EXPECT RATHER BENIGN CONDITIONS THU AFT
THROUGH FRIDAY WITH SLIGHTLY ABOVE NORMAL TEMPS. THEN ON SATURDAY
WILL KEEP THE LOW POPS IN THE FAR WEST WITH THE APPROACH OF THE NEXT
UPSTREAM TROUGH WITH THE EURO AGAIN FASTER THAN THE GFS SO WILL KEEP
THE TIMING OF THE ASCT PRECIP THE SAME WITH THE BLEND OF THE TWO
MODELS. TEMPS WILL WARM SOMEWHAT SATURDAY.

&&

.AVIATION.../06Z ISSUANCE/

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

VFR CONDITIONS WILL OCCUR TODAY AND TONIGHT. ISOLATED SHOWERS ARE
POSSIBLE ACROSS SOUTHERN NATRONA COUNTY FROM 21Z SUNDAY UNTIL 02Z
MONDAY. THE SHOWERS ARE NOT FORECAST TO HIT THE KCPR AIRPORT. A COLD
FRONT WILL PUSH THROUGH NORTHERN WY FROM 15Z TO 19Z AND PUSH SOUTH
INTO CENTRAL WY AROUND 00Z MONDAY. A WIND SHIFT TO THE NORTH WILL
BE THE MAIN IMPACT.

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

VFR CONDITIONS WILL OCCUR TODAY AND TONIGHT. ISOLATED SHOWERS WILL
BE POSSIBLE OVER THE NW WY MOUNTAINS UNTIL 18Z. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHERN WY FROM 19Z SUNDAY UNTIL
02Z MONDAY. THIS ACTIVITY MAY IMPACT THE KRKS AIRPORT DURING THIS
TIMEFRAME.

&&

.FIRE WEATHER...

IT WILL BE MILD TO WARM AND DRY THE REMAINDER OF THE WEEKEND AND
IN MOST AREAS THROUGH MONDAY. THERE WILL BE BREEZY TO WINDY AREAS
AT TIMES AND A COLD FRONT WILL SHIFT WINDS TO THE NORTH ACROSS THE
NORTH AND EAST PART OF THE DISTRICT ON SUNDAY WHILE WEST TO
NORTHWEST WINDS CONTINUE ELSEWHERE. WINDS WILL STRENGTHEN
CONSIDERABLY MONDAY NIGHT AND TUESDAY AHEAD OF A SIGNIFICANT STORM
SYSTEM THAT WILL MOVE EAST ACROSS THE AREA TUESDAY THROUGH
WEDNESDAY. STRONG TO VERY STRONG SOUTHERLY WINDS ARE EXPECTED ON
TUESDAY WITH SHOWERS AND POSSIBLE THUNDERSTORMS DEVELOPING OUT
WEST AND ISOLATED SHOWERS AND THUNDERSTORMS EAST OF THE DIVIDE.

&&

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

&&

$$

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










000
FXUS65 KCYS 200523
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1123 PM MDT SAT APR 19 2014

.UPDATE...
ISSUED AT 904 PM MDT SAT APR 19 2014

LATEST RADAR LOOP INDICATED THAT THE BULK OF THE SHOWERS HAD ENDED
ACROSS THE AREA. THEREFORE...PARTLY TO MOSTLY CLOUDY SKIES CAN BE
EXPECTED THE REMAINDER OF THE NIGHT. TEMPERATURE TRENDS APPEAR TO BE
ON TRACK FOR LOWS TONIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 230 PM MDT SAT APR 19 2014

EASTERLY WINDS AND CIRRUS CLOUDS HAVE HELD TEMPERATURES DOWN OVER
EASTERN PORTIONS OF THE FORECAST AREA. THESE COOLER BOUNDARY
LAYER/SURFACE TEMPERATURES WILL LIMIT THE CHANCES FOR
THUNDERSTORMS THE REST OF THIS AFTERNOON AND EVENING. LESS CLOUD
COVER IN THE WEST...MAINLY IN CARBON COUNTY WILL ALLOW FOR AT
LEAST A FEW LIGHTNING STRIKES. NOT LOOKING FOR ANY SEVERE STORMS
TODAY BUT GRAUPLE/SMALL HAIL AND GUSTY WINDS POSSIBLE WITH A FEW
OF THE STRONGER THUNDERSTORMS.

UPPER LEVEL SYSTEM CURRENTLY OVER COLORADO WILL DEPART INTO THE
PLAINS TONIGHT. FLOW WILL SLOWLY TURN TO THE WEST TONIGHT AND
TOMORROW MORNING BEHIND THE WAVE. WEAK UPPER LEVEL SUBSIDENCE
WILL SET IN SUNDAY BUT STILL THERE IS A CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS IN THE WEST. COOL AIR ALOFT AND STEEP LAPSE
RATES SHOULD ALLOW FOR SOME CONVECTION BUT AGAIN NO SEVERE WEATHER
THREAT. MONDAY SHOULD BE DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE AREA. A FEW SHOWERS POSSIBLE NEAR THE MOUNTAINS BUT THAT IS
ABOUT IT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT APR 19 2014

UPPER RIDGE AXIS WILL MOVE EAST OF THE CWA TUESDAY WHILE NEXT
UPPER TROF APPROACHES THE AREA FROM THE WEST COASTAL AREAS. A BIT
OF CONVECTION POSSIBLE TUESDAY AFTERNOON AND EVENING AS SOME WEAK
INSTABILITY SHOULD EXIST TO INTERACT WITH A MINOR IMPULSE IN THE
UPPER FLOW. TURNING COOLER WEDS AND THURSDAY AS THE UPPER TROF
PASSES ACROSS THE REGION. SCATTERED SHOWERS SHOULD ACCOMPANY THIS
SYSTEM BUT BE CONFINED MAINLY TO THE MTNS AND NORTHERN PARTS OF
THE CWA WHILE BREEZY TO WINDY DOWNSLOPE FLOW HINDERS ACTIVITY
ELSEWHERE. MAINLY DRY AND A LITTLE WARMER FOR FRIDAY AND SATURDAY
IN PROGRESSIVE UPPER FLOW PATTERN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1121 PM MDT SAT APR 19 2014

VFR CONDITIONS EXPECTED AS SOUTHEAST WYOMING AND NORTHERN COLORADO
REMAIN UNDER AN AREA OF HIGH PRESSURE. DO NOT FORSEE ANY WEATHER
IMPACTS TO AVIATION INTERESTS THE NEXT 24 TO 48 HOURS.

&&

.FIRE WEATHER...
ISSUED AT 230 PM MDT SAT APR 19 2014

NO FIRE WEATHER CONCERNS THROUGH MONDAY. HUMIDITY VALUES WILL
GENERALLY DROP TO AS LOW AS 20 PERCENT DURING THE AFTERNOON HOURS
WHILE RECOVERIES WILL BE INTO THE 70 TO 90 PERCENT RANGE. BREEZY
SUNDAY AFTERNOON...OTHERWISE WINDS WILL MAINLY BE ON THE LIGHT
SIDE. STRONGER WINDS LIKELY TUESDAY INTO WEDNESDAY.

&&

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

$$

UPDATE...REC
SHORT TERM...SML
LONG TERM...RE
AVIATION...CLAYCOMB
FIRE WEATHER...SML







000
FXUS65 KCYS 200311
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
911 PM MDT SAT APR 19 2014

.UPDATE...
ISSUED AT 904 PM MDT SAT APR 19 2014

LATEST RADAR LOOP INDICATED THAT THE BULK OF THE SHOWERS HAD ENDED
ACROSS THE AREA. THEREFORE...PARTLY TO MOSTLY CLOUDY SKIES CAN BE
EXPECTED THE REMAINDER OF THE NIGHT. TEMPERATURE TRENDS APPEAR TO BE
ON TRACK FOR LOWS TONIGHT.


&&

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 230 PM MDT SAT APR 19 2014

EASTERLY WINDS AND CIRRUS CLOUDS HAVE HELD TEMPERATURES DOWN OVER
EASTERN PORTIONS OF THE FORECAST AREA. THESE COOLER BOUNDARY
LAYER/SURFACE TEMPERATURES WILL LIMIT THE CHANCES FOR
THUNDERSTORMS THE REST OF THIS AFTERNOON AND EVENING. LESS CLOUD
COVER IN THE WEST...MAINLY IN CARBON COUNTY WILL ALLOW FOR AT
LEAST A FEW LIGHTNING STRIKES. NOT LOOKING FOR ANY SEVERE STORMS
TODAY BUT GRAUPLE/SMALL HAIL AND GUSTY WINDS POSSIBLE WITH A FEW
OF THE STRONGER THUNDERSTORMS.

UPPER LEVEL SYSTEM CURRENTLY OVER COLORADO WILL DEPART INTO THE
PLAINS TONIGHT. FLOW WILL SLOWLY TURN TO THE WEST TONIGHT AND
TOMORROW MORNING BEHIND THE WAVE. WEAK UPPER LEVEL SUBSIDENCE
WILL SET IN SUNDAY BUT STILL THERE IS A CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS IN THE WEST. COOL AIR ALOFT AND STEEP LAPSE
RATES SHOULD ALLOW FOR SOME CONVECTION BUT AGAIN NO SEVERE WEATHER
THREAT. MONDAY SHOULD BE DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE AREA. A FEW SHOWERS POSSIBLE NEAR THE MOUNTAINS BUT THAT IS
ABOUT IT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT APR 19 2014

UPPER RIDGE AXIS WILL MOVE EAST OF THE CWA TUESDAY WHILE NEXT
UPPER TROF APPROACHES THE AREA FROM THE WEST COASTAL AREAS. A BIT
OF CONVECTION POSSIBLE TUESDAY AFTERNOON AND EVENING AS SOME WEAK
INSTABILITY SHOULD EXIST TO INTERACT WITH A MINOR IMPULSE IN THE
UPPER FLOW. TURNING COOLER WEDS AND THURSDAY AS THE UPPER TROF
PASSES ACROSS THE REGION. SCATTERED SHOWERS SHOULD ACCOMPANY THIS
SYSTEM BUT BE CONFINED MAINLY TO THE MTNS AND NORTHERN PARTS OF
THE CWA WHILE BREEZY TO WINDY DOWNSLOPE FLOW HINDERS ACTIVITY
ELSEWHERE. MAINLY DRY AND A LITTLE WARMER FOR FRIDAY AND SATURDAY
IN PROGRESSIVE UPPER FLOW PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 555 PM MDT SAT APR 19 2014

LATEST RADAR LOOP WAS SHOWING A FEW SHOWERS CONTINUING TO FLARE UP
ACROSS THE LARAMIE RANGE. THESE SHOWERS MAY CONTAIN A FEW WIND
GUSTS UP TO 30 TO 40 MPH. OTHERWISE...THE SHOWER ACTIVITY SHOULD
BEGIN TO DIE OFF AFTER SUNSET. LIGHT WINDS CAN BE EXPECTED
OVERNIGHT INTO TOMORROW MORNING BEFORE ANOTHER WEAK BOUNDARY
PASSES THROUGH THE AREA DURING THE AFTERNOON ALONG WITH A FEW SHOWERS.
OTHERWISE...VFR CONDITIONS SHOULD BE THE RULE.


&&

.FIRE WEATHER...
ISSUED AT 230 PM MDT SAT APR 19 2014

NO FIRE WEATHER CONCERNS THROUGH MONDAY. HUMIDITY VALUES WILL
GENERALLY DROP TO AS LOW AS 20 PERCENT DURING THE AFTERNOON HOURS
WHILE RECOVERIES WILL BE INTO THE 70 TO 90 PERCENT RANGE. BREEZY
SUNDAY AFTERNOON...OTHERWISE WINDS WILL MAINLY BE ON THE LIGHT
SIDE. STRONGER WINDS LIKELY TUESDAY INTO WEDNESDAY.

&&

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

$$

UPDATE...REC
SHORT TERM...SML
LONG TERM...RE
AVIATION...REC
FIRE WEATHER...SML








000
FXUS65 KCYS 200001
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
601 PM MDT SAT APR 19 2014

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 230 PM MDT SAT APR 19 2014

EASTERLY WINDS AND CIRRUS CLOUDS HAVE HELD TEMPERATURES DOWN OVER
EASTERN PORTIONS OF THE FORECAST AREA. THESE COOLER BOUNDARY
LAYER/SURFACE TEMPERATURES WILL LIMIT THE CHANCES FOR
THUNDERSTORMS THE REST OF THIS AFTERNOON AND EVENING. LESS CLOUD
COVER IN THE WEST...MAINLY IN CARBON COUNTY WILL ALLOW FOR AT
LEAST A FEW LIGHTNING STRIKES. NOT LOOKING FOR ANY SEVERE STORMS
TODAY BUT GRAUPLE/SMALL HAIL AND GUSTY WINDS POSSIBLE WITH A FEW
OF THE STRONGER THUNDERSTORMS.

UPPER LEVEL SYSTEM CURRENTLY OVER COLORADO WILL DEPART INTO THE
PLAINS TONIGHT. FLOW WILL SLOWLY TURN TO THE WEST TONIGHT AND
TOMORROW MORNING BEHIND THE WAVE. WEAK UPPER LEVEL SUBSIDENCE
WILL SET IN SUNDAY BUT STILL THERE IS A CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS IN THE WEST. COOL AIR ALOFT AND STEEP LAPSE
RATES SHOULD ALLOW FOR SOME CONVECTION BUT AGAIN NO SEVERE WEATHER
THREAT. MONDAY SHOULD BE DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE AREA. A FEW SHOWERS POSSIBLE NEAR THE MOUNTAINS BUT THAT IS
ABOUT IT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT APR 19 2014

UPPER RIDGE AXIS WILL MOVE EAST OF THE CWA TUESDAY WHILE NEXT
UPPER TROF APPROACHES THE AREA FROM THE WEST COASTAL AREAS. A BIT
OF CONVECTION POSSIBLE TUESDAY AFTERNOON AND EVENING AS SOME WEAK
INSTABILITY SHOULD EXIST TO INTERACT WITH A MINOR IMPULSE IN THE
UPPER FLOW. TURNING COOLER WEDS AND THURSDAY AS THE UPPER TROF
PASSES ACROSS THE REGION. SCATTERED SHOWERS SHOULD ACCOMPANY THIS
SYSTEM BUT BE CONFINED MAINLY TO THE MTNS AND NORTHERN PARTS OF
THE CWA WHILE BREEZY TO WINDY DOWNSLOPE FLOW HINDERS ACTIVITY
ELSEWHERE. MAINLY DRY AND A LITTLE WARMER FOR FRIDAY AND SATURDAY
IN PROGRESSIVE UPPER FLOW PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 555 PM MDT SAT APR 19 2014

LATEST RADAR LOOP WAS SHOWING A FEW SHOWERS CONTINUING TO FLARE UP
ACROSS THE LARAMIE RANGE. THESE SHOWERS MAY CONTAIN A FEW WIND
GUSTS UP TO 30 TO 40 MPH. OTHERWISE...THE SHOWER ACTIVITY SHOULD
BEGIN TO DIE OFF AFTER SUNSET. LIGHT WINDS CAN BE EXPECTED
OVERNIGHT INTO TOMORROW MORNING BEFORE ANOTHER WEAK BOUNDARY
PASSES THROUGH THE AREA DURING THE AFTERNOON ALONG WITH A FEW SHOWERS.
OTHERWISE...VFR CONDITIONS SHOULD BE THE RULE.

&&

.FIRE WEATHER...
ISSUED AT 230 PM MDT SAT APR 19 2014

NO FIRE WEATHER CONCERNS THROUGH MONDAY. HUMIDITY VALUES WILL
GENERALLY DROP TO AS LOW AS 20 PERCENT DURING THE AFTERNOON HOURS
WHILE RECOVERIES WILL BE INTO THE 70 TO 90 PERCENT RANGE. BREEZY
SUNDAY AFTERNOON...OTHERWISE WINDS WILL MAINLY BE ON THE LIGHT
SIDE. STRONGER WINDS LIKELY TUESDAY INTO WEDNESDAY.

&&

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

$$

SHORT TERM...SML
LONG TERM...RE
AVIATION...REC
FIRE WEATHER...SML







000
FXUS63 KUNR 192339
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
539 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 538 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON.

&&

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

$$

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






000
FXUS63 KUNR 192339
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
539 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.


&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 538 PM MDT SAT APR 19 2014

SOUTHERLY WINDS TONIGHT WILL SHIFT TO THE NORTHWEST
SUNDAY AS A COLD FRONT PASSES THROUGH THE AREA. VFR CONDITIONS WILL
CONTINUE THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA ON SUNDAY AFTERNOON.

&&

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

$$

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







000
FXUS65 KCYS 192030
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
230 PM MDT SAT APR 19 2014

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 230 PM MDT SAT APR 19 2014

EASTERLY WINDS AND CIRRUS CLOUDS HAVE HELD TEMPERATURES DOWN OVER
EASTERN PORTIONS OF THE FORECAST AREA. THESE COOLER BOUNDARY
LAYER/SURFACE TEMPERATURES WILL LIMIT THE CHANCES FOR
THUNDERSTORMS THE REST OF THIS AFTERNOON AND EVENING. LESS CLOUD
COVER IN THE WEST...MAINLY IN CARBON COUNTY WILL ALLOW FOR AT
LEAST A FEW LIGHTNING STRIKES. NOT LOOKING FOR ANY SEVERE STORMS
TODAY BUT GRAUPLE/SMALL HAIL AND GUSTY WINDS POSSIBLE WITH A FEW
OF THE STRONGER THUNDERSTORMS.

UPPER LEVEL SYSTEM CURRENTLY OVER COLORADO WILL DEPART INTO THE
PLAINS TONIGHT. FLOW WILL SLOWLY TURN TO THE WEST TONIGHT AND
TOMORROW MORNING BEHIND THE WAVE. WEAK UPPER LEVEL SUBSIDENCE
WILL SET IN SUNDAY BUT STILL THERE IS A CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS IN THE WEST. COOL AIR ALOFT AND STEEP LAPSE
RATES SHOULD ALLOW FOR SOME CONVECTION BUT AGAIN NO SEVERE WEATHER
THREAT. MONDAY SHOULD BE DRY AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE AREA. A FEW SHOWERS POSSIBLE NEAR THE MOUNTAINS BUT THAT IS
ABOUT IT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT APR 19 2014

UPPER RIDGE AXIS WILL MOVE EAST OF THE CWA TUESDAY WHILE NEXT
UPPER TROF APPROACHES THE AREA FROM THE WEST COASTAL AREAS. A BIT
OF CONVECTION POSSIBLE TUESDAY AFTERNOON AND EVENING AS SOME WEAK
INSTABILITY SHOULD EXIST TO INTERACT WITH A MINOR IMPULSE IN THE
UPPER FLOW. TURNING COOLER WEDS AND THURSDAY AS THE UPPER TROF
PASSES ACROSS THE REGION. SCATTERED SHOWERS SHOULD ACCOMPANY THIS
SYSTEM BUT BE CONFINED MAINLY TO THE MTNS AND NORTHERN PARTS OF
THE CWA WHILE BREEZY TO WINDY DOWNSLOPE FLOW HINDERS ACTIVITY
ELSEWHERE. MAINLY DRY AND A LITTLE WARMER FOR FRIDAY AND SATURDAY
IN PROGRESSIVE UPPER FLOW PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1240 PM MDT SAT APR 19 2014

PLENTY OF MID AND HIGH CLOUDS WILL MOVE OVER THE AERODROMES THIS
AFTERNOON THEN SOME CLEARING EXPECTED TONIGHT.  MAINLY VFR THROUGH
SUNDAY BUT SOME PDS OF MVFR VSBYS POSSIBLE WITH ANY SHOWERS THAT
MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING.

&&

.FIRE WEATHER...
ISSUED AT 230 PM MDT SAT APR 19 2014

NO FIRE WEATHER CONCERNS THROUGH MONDAY. HUMIDITY VALUES WILL
GENERALLY DROP TO AS LOW AS 20 PERCENT DURING THE AFTERNOON HOURS
WHILE RECOVERIES WILL BE INTO THE 70 TO 90 PERCENT RANGE. BREEZY
SUNDAY AFTERNOON...OTHERWISE WINDS WILL MAINLY BE ON THE LIGHT
SIDE. STRONGER WINDS LIKELY TUESDAY INTO WEDNESDAY.

&&

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

$$

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





000
FXUS63 KUNR 192026
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
226 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.

&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND
SOUTH CENTRAL SOUTH DAKOTA ON SUNDAY AFTERNOON.

&&

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

$$

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






000
FXUS63 KUNR 192026
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
226 PM MDT SAT APR 19 2014

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT APR 19 2014

UPPER LEVEL ANALYSIS HAS CUT OFF LOWS ACROSS MANITOBA AND ARIZONA
WITH NEAR ZONAL FLOW ACROSS THE NW CONUS. NEXT UPPER TROF JUST NOW
MAKING ITS WAY INTO THE PACIFIC NORTHWEST. SKIES ARE SUNNY WITH
SOME MID LEVEL CLOUDS CROSSING SOUTH CENTRAL SOUTH DAKOTA. AT THE
SURFACE...HIGH PRESSURE IS LOCATED ACROSS THE NORTHERN AND CENTRAL
PLAINS. TEMPERATURES ARE IN THE 50S AND 60S WITH VARIABLE AND
BREEZY WINDS IN SPOTS.

WARM WEATHER WILL PERSIST THROUGH SUNDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT REMAIN OVER THE AREA. WARMER AIR WILL RETURN
TONIGHT AND SUNDAY AS WINDS SHIFT TO THE SOUTH-SOUTHEAST. SUNDAY
WILL SEE TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND
EVENING...BRINGING BRISK NORTHWEST WINDS BEHIND IT. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK. DRY
WEATHER RETURNS FOR SUNDAY NIGHT.

&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING WARMER THAN AVERAGE TEMPERATURES
TO THE NORTHERN PLAINS ON MONDAY AND TUESDAY. FORECAST MODELS
CONTINUE TO SHOW AN UPPER LEVEL TROUGH AFFECTING THE AREA FROM
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SHOW THE ECMWF IS
FAVORING SLIGHTLY FASTER MOVEMENT TO THE SYSTEM AND IS ALSO
FARTHER NORTH WITH THE UPPER LOW COMPARED TO THE LATEST GFS
SOLUTION. IN GENERAL THE RESULT WILL BE INCREASING CHANCES FOR
PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS INCREASING
GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW DEVELOPS OVER
THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST. GENERAL CHANCE
POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH AT NIGHT FOR A
BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY NIGHT/THURSDAY
MORNING AND THEN ON THE PLAINS THURSDAY NIGHT. MODEL SOLUTIONS
DIVERGE FOR FRIDAY AND SATURDAY DUE TO THE DIFFERENCES IN SPEED
AND TIMING OF THE EASTWARD PROGRESS OF THE UPPER TROUGH ON
FRIDAY AND THE TIMING OF THE NEXT TROUGH APPROACHING FROM THE WEST
ON SATURDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 210 PM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS OVER PARTS OF SOUTHWESTERN AND
SOUTH CENTRAL SOUTH DAKOTA ON SUNDAY AFTERNOON.

&&

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

$$

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







000
FXUS65 KRIW 191956
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
156 PM MDT SAT APR 19 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY

WEAK SHORTWAVE MOVED INTO THE SW THIS MORNING WITH ACCAS AND
SPRINKLES. THIS AREA HAS NOW TURNED INTO LIGHT SHOWERS AND IS
MERGING WITH OUR MOISTURE...LEFTOVER FRONTAL BOUNDARY AND DAYTIME
HEATING TO PRODUCING SOME BUILDING CUMULUS OVER SWEETWATER COUNTY.
IDEA OF MAINLY ISOLATED SHOWERS AND A COUPLE THUNDERSTORMS IS
LOOKING GOOD WITH A FEW MORE OVER THE MOUNTAINS. COUPLE LIGHTNING
STRIKES JUST SOUTH OF THE BORDER SO FAR. NEXT SYSTEM MOVES EWD
AWAY FROM THE UPPER LOW OFF THE B.C. COAST WHICH PUSHES A COLD
FRONT SE ACROSS THE AREA ON EASTER. THE FRONT MAY INTERACT WITH
THE LEFTOVER MOISTURE FROM TODAY`S SYSTEM OVER OUR FAR SERN ZONES
TO PROVIDE ANOTHER DAY OF MAINLY ISOLATED SHOWERS AND PERHAPS A
THUNDERSTORM OR TWO. INSTABILITY LOOKS VERY LIMITED ON
FORECAST/INTERPOLATED SOUNDINGS. OTHERWISE...ANOTHER MILD DAY
WITH TEMPERATURES GENERALLY 60S EAST OF THE DIVIDE AND 50S TO
LOWER 60S WEST. THE MOUNTAINS WILL BE IN THE 40S AND 50S. RIDGE
AXIS MOVES OVERHEAD ON MONDAY WITH SLIGHTLY WARMER TEMPERATURES
YET. COULD BE A FEW SHOWERS TRYING TO DEVELOP OVER THE FAR WEST BY
MONDAY EVENING AS SOME MOISTURE FROM THE ERN FRINGES OF OUR BIG
MIDWEEK SYSTEM WORKS ON A WARM TEMPERATURES MONDAY.
OTHERWISE...MONDAY LOOKS DRY AND MILD TO WARM. TUESDAY WE STILL
OUR BIG NEGATIVELY TILTED UPPER LOW MOVE INTO THE GREAT BASIN WITH
RAPIDLY FALLING PRESSURES AS A SURFACE LOW FORMS OVER MONTANA.
STRONG SLY FLOW WHICH WILL DEVELOP MONDAY NIGHT WILL CONTINUE TO
STRENGTHEN THROUGH THE DAY TUESDAY LEADING TO A WINDY TO VERY
WINDY DAY FOR MOST EVERYONE. COLD FRONT NEAR THE FAR WEST LATE IN
THE DAY WITH A LINE OF SHOWERS AND THUNDERSTORMS QUITE LIKELY OUT
WEST. A FEW OF THESE COULD BE QUITE STRONG EVEN IF IT`S JUST
SHOWERS AND OR THUNDERSTORMS MOVING NWD AND ADDING TO THE AMBIENT
STRONG SLY FLOW PRODUCING VERY STRONG SLY WINDS. EAST OF THE
DIVIDE...DAYTIME HEATING MAY BE ENOUGH FOR ISOLATED SHOWERS AND
THUNDERSTORMS WITH SOME RETURN FLOW MOISTURE AND HIGHER CAPES
POSSIBLE IN JOHNSON COUNTY. OTHERWISE...WARM AND WINDY WITH PCPN
BECOMING FAIRLY WIDESPREAD OUT WEST. SNOW LEVELS WILL BE ABOVE 10K
FEET DURING THE DAY ADDING TO THE RISK OF SOME MODERATE TO LOCALLY
HEAVY RAIN ON DEEP SNOWPACK.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

A VIGOROUS SHORTWAVE TRACKING NORTHEAST AROUND THE BASE OF THE DEEP
TROUGH THAT WILL BE SITUATED ALONG THE CANADIAN/PACIFIC NORTHWEST
COAST TUE NT WILL PRODUCE NUMEROUS RAIN AND SNOW SHOWERS IN THE FAR
WEST TUESDAY NIGHT WITH 2 TO 3 INCHES OF ACCUMULATING SNOW AFTER
MIDNIGHT IN THE FAR WEST. SOME ISOLATED THUNDER ALSO POSSIBLE.
PRECIPITATION WILL SPILL OVER TO AREAS EAST OF THE DIVIDE LATER
TUESDAY NIGHT AND INTO WEDNESDAY. WEDNESDAY WILL FEATURE PRECIP
MAINLY IN THE FORM OF RAIN EXCEPT MOSTLY SNOW IN THE MOUNTAINS. BY
WEDNESDAY...THE AFOREMENTIONED TROUGH WILL CLOSE INTO AN ALMOST
VERTICALLY STACKED LOW OVER MONTANA AS IT TRACKS EAST. HIGH TEMPS
WED SHOULD RUN ABOUT 10 TO 20 DEGREES COOLER COMPARED TO TUE.THERE
WILL BE MORE PRECIP ACROSS THE NORTH HALF OF THE CWA WEDNESDAY NIGHT
CLOSER TO THE TRACK OF THE LOW. DURING THE COURSE OF THE NIGHT
WEDNESDAY NIGHT...H7 TEMPS WILL DROP TO -10C WEST OF THE DIVIDE AND
-8C EAST SO THAT BY 06Z THU...MOST OF WHAT PRECIP OCCURS WILL BE IN
THE FORM OF SNOWFALL. BY WEDNESDAY NIGHT...WITH ENOUGH COLD AIR
ALOFT DESTABILIZING THE ATMOSPHERE...EXPECT CONVECTIVE SNOW BANDS TO
FORM OFF SOUTH PASS...THE OWL CREEK/BRIDGER MTNS AND THE BIG HORN
MTNS IN THE FAVORABLE NORTHWEST FLOW...WITH THESE SNOW BANDS LIKELY
EXTENDING INTO THE LOWER ELEVATIONS OF EASTERN FREMONT...NATRONA AND
JOHNSON COUNTIES AS WELL AS GREATER CASPER. THE ECMWF IS SLOWER THAN
THE GFS WITH THIS TROUGH SO KEPT THE TIMING OF THE PRECIP THE SAME
WHICH IS A BLEND OF THE SPEED OF THE TWO MODELS. SNOWFALL WILL TAPER
OFF THURSDAY MORNING. EXPECT RATHER BENIGN CONDITIONS THU AFT
THROUGH FRIDAY WITH SLIGHTLY ABOVE NORMAL TEMPS. THEN ON SATURDAY
WILL KEEP THE LOW POPS IN THE FAR WEST WITH THE APPROACH OF THE NEXT
UPSTREAM TROUGH WITH THE EURO AGAIN FASTER THAN THE GFS SO WILL KEEP
THE TIMING OF THE ASCT PRECIP THE SAME WITH THE BLEND OF THE TWO
MODELS. TEMPS WILL WARM SOMEWHAT SATURDAY.

&&

.AVIATION.../00Z ISSUANCE/

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

VFR CONDITIONS WITH ONLY FEW-SCT HIGH CLOUDS AND MAINLY LIGHT WINDS
ARE EXPECTED THROUGH THE FORECAST PERIOD. HOWEVER...SOME ISOLATED
SHOWERS OR EVEN A THUNDERSTORM COULD FORM IN SOUTHEAST SWEETWATER
COUNTY DURING THE REMAINDER OF THIS AFTERNOON. WINDS WILL VEER TO
THE NORTH DURING THE COURSE OF THE AFTERNOON ON SUNDAY AS A WEAK
FRONTAL BOUNDARY PUSHES SOUTH OVER THE AREA.

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

THERE IS THE POSSIBILITY OF ISOLATED CONVECTION SOUTH OF INTERSTATE
80. THIS ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS TERMINAL...BUT THE
TERMINAL COULD SEE SOME OUTFLOW WINDS FROM THE ACTIVITY.
OTHERWISE...VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED.

&&

.FIRE WEATHER...

IT WILL BE MILD TO WARM AND DRY THE REMAINDER OF THE WEEKEND AND
IN MOST AREAS THROUGH MONDAY. THERE WILL BE BREEZY TO WINDY AREAS
AT TIMES AND A COLD FRONT WILL SHIFT WINDS TO THE NORTH ACROSS THE
NORTH AND EAST PART OF THE DISTRICT ON SUNDAY WHILE WEST TO
NORTHWEST WINDS CONTINUE ELSEWHERE. WINDS WILL STRENGTHEN
CONSIDERABLY MONDAY NIGHT AND TUESDAY AHEAD OF A SIGNIFICANT STORM
SYSTEM THAT WILL MOVE EAST ACROSS THE AREA TUESDAY THROUGH
WEDNESDAY. STRONG TO VERY STRONG SOUTHERLY WINDS ARE EXPECTED ON
TUESDAY WITH SHOWERS AND POSSIBLE THUNDERSTORMS DEVELOPING OUT
WEST AND ISOLATED SHOWERS AND THUNDERSTORMS EAST OF THE DIVIDE.

&&

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

&&

$$

SHORT TERM...SKRBAC
LONG TERM...LIPSON
AVIATION...LIPSON
FIRE WEATHER...SKRBAC







000
FXUS65 KRIW 191727
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1127 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY STILL SHOWS PROGRESSIVE/FAST MOVING NRN BRANCH OF POLAR
FLOW ATOP SOMEWHAT SLOWER SRN BRANCH OF SUB-TROPICAL FLOW STRETCHING
ACROSS THE ENTIRE CONUS. THERE ARE NO LESS THAN 5 ACTIVE UPR LOWS
ENCOMPASSING THE CONUS...WITH EACH TRYING TO STEAL SOME THUNDER FROM
THE OTHER...KEEP ALL IN CHECK FOR THE MOST PART. HERE...UPR TROF
THRU WITH A COUPLE OF MOSTLY DRY FRONTS DRAPED ACROSS THE SRN AND
NRN FA. BENIGN HIGH PRESSURE WITH WEAK GRADIENT SLOWLY INFILTRATING
FROM THE NW...REIGNING IN THE WINDS FOR A WHILE ANYWAY.

GENERALLY...TODAY WILL BE SLIGHTLY COOLER THAN FRIDAY...WITH HIGH
TEMPS STILL REACHING INTO THE MIDDLE AND UPPER 60S FOR MOST OF THE
LOWER ELEVATIONS. OTHERWISE...NEARLY STATIONARY FRONT SET UP NEAR/
NORTH OF THE WY/CO BORDER IN OUR SRN MOST ZONES WILL AID IN RENEWED
CONVECTIVE DEVELOPMENT BY MID DAY IN A LARGELY DRY ADIABATIC
ATMOSPHERE. THIS AREA MAY LIFT FAR ENOUGH NORTH THAT SOME ACTIVITY
MAY PRESENT ITSELF OVR SRN NATRONA COUNTY TOO. WON`T HELP MUCH
HOWEVER AS CONVECTIVE MODE WILL HAVE LITTLE MOISTURE TO WORK
WITH...YIELDING MOSTLY DRY SHOWERS/STORMS WITH GUSTY WINDS.

SUNDAY WILL BE NICE OVERALL. THE AFTERNOON WILL OFFER LOW END
CHANCES FOR ISOLATED TO WIDELY SCATTERED SHOWERS WITH SOME THUNDER
AS A WEAK UPR LVL DISTURBANCE AND SFC FRONT RACE THROUGH THE FA.
TIMING AND MARGINALLY AVAILABLE MOISTURE WILL LIMIT THE CONVECTIVE
AREA TO OUR SRN AND SERN ZONES. HOWEVER...THIS WILL BE ANOTHER CASE
OF HIGH BASED SHOWERS/FEW STORMS WITH LITTLE RAIN...AND MORE GUSTY
WINDS. MONDAY THRU MOST OF THE DAY...UPR RIDGE AND STABLE ATMOSPHERE
IN PLACE. BY EVENING HOWEVER...RIDGE AXIS STARTS TO HEAD OUT WHILE
TROF FROM THE WEST BEGINS TO MOVE IN WITH PVA STARTING AS PART OF
POLAR JET...CURRENTLY HOVERING OVR THE EPAC REGION W OF
WA/OR...WORKS ITS WAY INTO THE WRN MOUNTAINS WITH A LITTLE MOISTURE.
THIS WILL HERALD THE BEGINNING OF NEW CYCLOGENESIS IN THE PAC NW
STATES THAT WILL AFFECT OUR CWA IN SOME RESPECT THROUGH THE MIDDLE
OF NEXT WEEK.

.LONG TERM...TUESDAY THROUGH SATURDAY

UPPER LOW ALONG THE EASTERN END OF THE ALEUTIANS EARLY THIS MORNING
WILL DIG INTO THE EASTERN PACIFIC AND MOVE ONTO THE WEST COAST
TUESDAY MORNING...WITH UPPER TROUGH LIFTING ACROSS THE ROCKIES ON
WEDNESDAY.  ASSOCIATED SURFACE COLD FRONT WILL SLOWLY MOVE EAST
ACROSS IDAHO TUESDAY...INTO THE WEST TUESDAY AFTERNOON...AND ACROSS
CENTRAL WYOMING TUESDAY NIGHT.  ECMWF AND GFS SPREAD INCREASES AS
THE UPPER TROUGH CROSSES THE DIVIDE...THE ECMWF REMAINS QUICKER
BUILDING A RIDGE IN BEHIND THE TROUGH ON THURSDAY WHILE THE GFS
KEEPS A COOL UNSETTLED NW FLOW OVER THE AREA...BEFORE BUILDING THE
RIDGE IN THURSDAY NIGHT.  OPERATIONAL ECMWF IS SLIGHTLY FASTER THAN
THE EC ENSEMBLE MEAN WHILE THE GFS OPERATIONAL IS SLIGHTLY SLOWER
AND DEEPER THAN ITS ENSEMBLE MEAN.  SPLITTING THE DIFFERENCE WOULD
PUT THE UPPER TROUGH AXIS ROUGHLY ALONG 100W BY 00Z FRIDAY AND THE
UPSTREAM RIDGE ALONG 115W...WITH THIS RIDGE TRANSLATING THE AREA ON
FRIDAY AS NEXT PACIFIC TROUGH PUSHES ONTO THE WEST COAST.

FOR SENSIBLE WEATHER...

ON TUESDAY...VERY MILD AND WINDY CONDITIONS WILL DEVELOP ACROSS
CENTRAL AREAS AS PACIFIC COLD FRONT PUSHES ACROSS IDAHO WITH
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS THE
WEST...SHOWERS AND ISOLATED STORMS SPREADING EAST LATE IN THE DAY.
SNOW LEVELS WILL REMAIN QUITE HIGH TUESDAY AHEAD OF THE
FRONT...GENERALLY AROUND 10KFT AND UP. RAPID SNOW MELT AND
SIGNIFICANT RISES IN CREEKS AND STREAMS WILL BE A CONCERN WITH THE
WARM TEMPERATURES...ESPECIALLY WITH THE POTENTIAL FOR RAIN NEAR
AND BELOW 10KFT.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...COLD FRONT WILL PUSH ACROSS THE
AREA SPREADING SHOWERS AND ISOLATED THUNDERSTORMS EAST OF THE DIVIDE
WITH SNOW LEVELS LOWERING TO THE VALLEY FLOORS IN THE WEST.  WNW
MOIST CYCLONIC FLOW ON BACKSIDE OF TROUGH LOOKS TO BRING SIGNIFICANT
SNOW ACCUMULATIONS FROM TETON...TOGWOTEE PASS NORTH TO YNP AND
THE BEARTOOTH PASS AREA WEDNESDAY AND WEDNESDAY NIGHT. GUSTY
DOWNSLOPE WEST WINDS WILL HINDER PRECIPITATION EAST OF THE DIVIDE
BEHIND THE COLD FRONT ON WEDNESDAY WITH THE BEST CHANCES OF RAIN
OR A RAIN AND SNOW MIX ACROSS THE NORTH AND SWEETWATER COUNTY.
HOWEVER...COLDER AND UNSTABLE NW FLOW PREVAIL BEHIND THE SYSTEM
WEDNESDAY NIGHT WITH SIGNIFICANT SNOW POSSIBLE IN THE BIGHORN
RANGE WITH POSSIBLY SOME HEAVIER CONVECTIVE SNOWBANDS FORMING IN
THE CENTRAL BASINS.

THURSDAY...FORECAST MAINTAINS CHANCES OF SNOW SHOWERS IN THE
NORTHERN MOUNTAINS WITH SLIGHT CHANCES OF RAIN/SNOW SHOWERS ACROSS
THE LOWER ELEVATIONS OF THE NORTH.  GUSTY W-NW WINDS AND SEASONABLY
COOL CONDITIONS OTHERWISE.

FRIDAY AND SATURDAY...WARMING TREND WITH BACKING SW FLOW AHEAD OF
NEXT PACIFIC TROUGH WITH INCREASING CHANCES OF SHOWERS IN THE
WEST...SLIGHT CHANCES OF SHOWERS EAST OF THE DIVIDE ON SATURDAY.

&&

.AVIATION.../18Z ISSUANCE/

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

VFR CONDITIONS WITH ONLY FEW-SCT HIGH CLOUDS AND MAINLY LIGHT WINDS
ARE EXPECTED THROUGH THE FORECAST PERIOD. HOWEVER...SOME ISOLATED
SHOWERS OR EVEN A THUNDERSTORM COULD FORM IN SOUTHEAST SWEETWATER
COUNTY THIS AFTERNOON. WINDS WILL VEER TO THE NORTH DURING THE
COURSE OF THE AFTERNOON ON SUNDAY AS A WEAK FRONTAL BOUNDARY PUSHES
SOUTH OVER THE AREA.

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

THERE IS THE POSSIBILITY OF ISOLATED CONVECTION SOUTH OF INTERSTATE
80. THIS ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS TERMINAL...BUT THE
TERMINAL COULD SEE SOME OUTFLOW WINDS FROM THE ACTIVITY.
OTHERWISE...VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED.

&&

.FIRE WEATHER...

TODAY...HIGH TEMPERATURES WILL BE WARM AND SEASONAL...WITH
MUCH LIGHTER WINDS THAN ON FRIDAY. ISOLATED CHANCES FOR MOSTLY DRY
SHOWERS OR AN ISOLATED THUNDERSTORM WILL BE POSSIBLE SOUTH OF A ROCK
SPRINGS TO CASPER LINE.  SUNDAY WILL BE SIMILAR IN MANY
RESPECTS...WITH HIGH TEMPERATURES A FEW DEGREES WARMER AND SLIGHT
CHANCES FOR SHOWERS A JUST BIT FURTHER NORTH. WINDS WILL BEGIN TO
SLOWLY INCREASE MONDAY NIGHT AS WILL CHANCES FOR PRECIPITATION IN
THE WESTERN MOUNTAIN ZONES...AS THE NEXT UPPER LEVEL DISTURBANCE
APPROACHES FROM THE WEST...HERALDING THE BEGINNING OF A COUPLE OF
DAYS OF PRECIPITATION OUT WEST. SIGNIFICANT MOUNTAIN SNOWS WILL BE
POSSIBLE STARTING TUESDAY NIGHT. OTHERWISE...WARM AND DRY ACROSS THE
CENTRAL AND SOUTHERN DISPATCH ZONES THROUGH TUESDAY NIGHT...WITH
WINDY CONDITIONS COMMENCING ACROSS ALL ZONES FROM TUESDAY NIGHT AND
LASTING THROUGH THURSDAY. THERE WILL BE SOME ENHANCED FIRE
DANGER...ESPECIALLY ON TUESDAY...AS THE WARMEST TEMPERATURE OF THE
SEASON COMBINE WITH THE STRONG WINDS. COOLER TEMPERATURES BOTH
WEDNESDAY AND THURSDAY WILL THEN MODERATE THE DANGER TO SOME
EXTENT.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...AEM
AVIATION...LIPSON
FIRE WEATHER...BRAUN












000
FXUS63 KUNR 191727
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1127 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.


&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1126 AM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10






000
FXUS63 KUNR 191727
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1127 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.


&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1126 AM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10






000
FXUS63 KUNR 191727
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1127 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.


&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1126 AM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10






000
FXUS63 KUNR 191727
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1127 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.


&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1126 AM MDT SAT APR 19 2014

VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10






000
FXUS65 KCYS 191724
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1124 AM MDT SAT APR 19 2014

.UPDATE...
ISSUED AT 1046 AM MDT SAT APR 19 2014

FORECAST PRETTY WELL ON TRACK FOR TODAY. ONLY CONCERN IS THICK
CIRRUS OVER MOST OF THE SOUTHEAST FORECAST INHIBITING
THUNDERSTORM CHANCES TODAY. COOL NORTHEAST UPSLOPE WILL NOT HELP
WITH SURFACE BASED INSTABILITY EAST OF THE LARAMIE RANGE AND WINDS
WILL BE SLOWER TO COME AROUND TO THE SOUTH THAN MODELS EARLIER
PROJECTED. NAM AND GFS HAS BACKED OFF ON THE SLIGHTLY NEGATIVE
LIFTED INDEX AND LOOKING AT MODEL SOUNDINGS...STEEP SURFACE BASED
LAPSE RATES WILL BE TOUGH TO COME BY EAST OF THE LARAMIE RANGE.
REMOVED THUNDERSTORM MENTION EAST OF THE LARAMIE RANGE FOR
TODAY...BUT KEPT IT GOING TO THE WEST WHERE MORNING SUNSHINE WILL
PRODUCE THOSE STEEPER LAPSE RATES. CAN NOT COMPLETELY RULE OUT
SOME ELEVATED CONVECTION WITH LIGHTNING EVEN EAST OF THE LARAMIE
RANGE AS THE NORTHERN FRINGES OF AN UPPER LEVEL DISTURBANCE WILL
IMPACT THE SOUTHERN CWA...BUT WITH ONLY WEAK FORCING...LIGHTNING
CHANCES ARE REMOTE AT BEST. GUSTY WINDS AND SMALL GRAUPLE
CERTAINLY A POSSIBILITY WEST OF THE LARAMIE RANGE WITH ANY
STRONGER CONVECTION...BUT SEVERE THUNDERSTORMS NOT LIKELY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)

ISSUED AT 256 AM MDT SAT APR 19 2014

AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA THIS
AFTERNOON...WITH SURFACE WINDS VEERING TO THE SOUTHEAST ACROSS THE
PLAINS AND INCREASING IN STRENGTH. DEW POINTS WILL INCREASE INTO THE
UPPER 30S TO LOW 40S ACROSS THE PLAINS IN THIS MOISTURE ADVECTION
PATTERN WITH WEAK INSTABILITY PROGGED FOR THE AFTERNOON. HIGH CLOUD
COVER WILL KEEP TEMPS ON THE COOL SIDE AND THUS INSTABILITY WILL
BE LOW...BUT THE COMBO OF UPPER SUPPORT AND WEAK INSTABILITY WILL
SUPPORT A GOOD CHANCE FOR RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON ESPECIALLY FOR THE MOUNTAINS AND NEARBY PLAINS.
LOOKS AS THOUGH AREAS FROM THE LARAMIE RANGE TO THE I-25 CORRIDOR
COULD SEE THE BEST CHANCE FOR STORMS OUTSIDE THE MOUNTAINS WHERE
NAM PAINTS INSTABILITY AS HIGH AS 200 J/KG WITHIN THE
BEST...ALBEIT RELATIVELY WEAK...MOISTURE CONVERGENCE ZONE. SHOULD
SEE WETTING RAINS WITH THIS ACTIVITY AS PRECIPITABLE WATER VALUES
WILL INCREASE TO BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH
THROUGH THE AFTERNOON. CONVECTION WILL DIMINISH THROUGH THE
EVENING AS THE UPPER WAVE WEAKENS AND MOVES EAST.

FOR SUNDAY...A COLD FRONT ASSOCIATED WITH A SHORTWAVE MOVING ACROSS
US/CANADIAN BORDER WILL DROP SOUTH ACROSS THE EASTERN PLAINS IN THE
AFTERNOON. TEMPS WILL WARM INTO THE UPPER 60S TO UPPER 70S IN THE
LOWER ELEVATIONS AHEAD OF THE FRONT...WITH LI`S DROPPING TO AROUND
ZERO. TIMING OF THE FRONT COULD FAVOR DEVELOPMENT OF AFTERNOON
SHOWERS AND A FEW WEAK THUNDERSTORMS...ESPECIALLY ALONG THE LARAMIE
RANGE AND CHEYENNE RIDGE WHERE LLVL FORCING AND INSTABILITY ARE
MAXIMIZED. A WEAK DISTURBANCE MOVING OVERHEAD FROM THE WEST WILL
TRIGGER A FEW TSTORMS OVER THE MOUNTAINS IN THE AFTERNOON AS WELL.

SFC HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR MONDAY WITH MAX
TEMPS EXPECTED TO BE ABOUT 5F COOLER. SFC WINDS WILL VEER BACK TO
THE SOUTH-SOUTHEAST IN THE AFTERNOON AND SO MAY SEE A FEW RAIN
SHOWERS DEVELOP WITHIN THE CONVERGENCE ZONE VCTY LARAMIE RANGE.
COOLER SFC TEMPS AND WAA ALOFT DUE TO A BUILDING UPPER RIDGE FROM
THE WEST WILL MINIMIZE INSTABILITY AND THUS TSTORM CHANCES.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MDT SAT APR 19 2014

PRETTY STRONG LOW PRESSURE SYSTEM IN THE EXTENDED EXPECTED TO
BRING VERY STRONG WINDS AND SOME PRECIP CHANCES TO THE CWFA. THESE
ARE THE CHALLENGES IN THE LONG TERM.

FOR MONDAY NIGHT INTO TUESDAY...UPPER LEVEL RIDGING BUILDS INTO
THE AREA WITH 700MB TEMPERATURES CLIMBING FROM +4C MONDAY
AFTERNOON UP TO +8C TUESDAY AFTERNOON. LOOKS LIKE A PRETTY WARM
DAY TUESDAY WITH 80S RETURNING TO THE PANHANDLE AND UPPER 60S/LOW
70S FOR AREAS WEST OF THE LARAMIE RANGE.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO SOUTHERN
NEVADA TO NORTHERN UTAH TUESDAY AFTERNOON...THEN INTO WESTERN
WYOMING TUESDAY NIGHT. AHEAD OF THIS LOW...700MB WINDS BECOME
QUITE STRONG WITH THE GFS SHOW 50KTS AT 700MBS WEDNESDAY MORNING.
700MB CRAIG TO CASPER HEIGHT GRADIENT AT 60MTRS TUESDAY NIGHT AND
INCREASES TO 70MTRS DURING THE MORNING WEDNESDAY. WILL NEED TO
MONITOR THIS FOR POSSIBLE WIND HEADLINES DURING THIS
TIME FRAME...AT LEAST FOR OUR WIND PRONE AREAS.

COLD FRONT ASSOCIATED WITH THIS LOW LOOKS TO MOVE INTO THE AREA
WEDNESDAY AFTERNOON WITH 700MB TEMPERATURES FALLING TO -6C ACROSS
CARBON COUNTY WEDNESDAY NIGHT. FOR NOW...BEST CHANCES FOR PRECIP
LOOK TO BE THE MOUNTAINS AND AREAS WEST OF THE LARAMIE RANGE.
AREAS EAST WILL BE IMPACTED BY DOWNSLOPING WINDS...SO KEPT THESE
AREAS DRY.

CONCERNS FOR WIND HEADLINES SHIFTS EAST INTO THE PANHANDLE
WEDNESDAY NIGHT AS GFS 850MB WINDS INCREASE TO 40KTS. SHOULD BE AT
LEAST WIND ADVISORY CRITERIA OUT THERE...CONTINUING INTO THURSDAY
AFTERNOON.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1124 AM MDT SAT APR 19 2014

PLENTY OF MID AND HIGH CLOUDS WILL MOVE OVER THE AERODROMES THIS
AFTERNOON THEN SOME CLEARING EXPECTED TONIGHT.  MAINLY VFR THROUGH
SUNDAY BUT SOME PDS OF MVFR VSBYS POSSIBLE WITH ANY SHOWERS THAT
MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING.

&&

.FIRE WEATHER...
ISSUED AT 256 AM MDT SAT APR 19 2014

TEMPERATURES WILL BE COOLER TODAY WITH HIGHER HUMIDITIES AND LESS
WIND. CHANCES FOR WETTING RAINS AND ISOLATED THUNDERSTORMS WILL
INCREASE THIS AFTERNOON AND WILL CONTINUE THROUGH THE EVENING AS A
WEATHER DISTURBANCE TRACKS ACROSS THE REGION. ANOTHER COLD FRONT
WILL DROP SOUTH ACROSS THE AREA ON SUNDAY AND WILL BRING A SLIGHT
CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE
MOUNTAINS AND AREAS NEAR THE COLORADO BORDER. AFTER A COOLER DAY
MONDAY...EXPECT WARMER AND DRIER CONDITIONS FOR TUESDAY WITH WINDY
CONDITIONS POSSIBLE FOR WEDNESDAY.

&&

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

$$

UPDATE...SML
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...RE
FIRE WEATHER...RJM






000
FXUS65 KCYS 191658
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1058 AM MDT SAT APR 19 2014

.UPDATE...
ISSUED AT 1046 AM MDT SAT APR 19 2014

FORECAST PRETTY WELL ON TRACK FOR TODAY. ONLY CONCERN IS THICK
CIRRUS OVER MOST OF THE SOUTHEAST FORECAST INHIBITING
THUNDERSTORM CHANCES TODAY. COOL NORTHEAST UPSLOPE WILL NOT HELP
WITH SURFACE BASED INSTABILITY EAST OF THE LARAMIE RANGE AND WINDS
WILL BE SLOWER TO COME AROUND TO THE SOUTH THAN MODELS EARLIER
PROJECTED. NAM AND GFS HAS BACKED OFF ON THE SLIGHTLY NEGATIVE
LIFTED INDEX AND LOOKING AT MODEL SOUNDINGS...STEEP SURFACE BASED
LAPSE RATES WILL BE TOUGH TO COME BY EAST OF THE LARAMIE RANGE.
REMOVED THUNDERSTORM MENTION EAST OF THE LARAMIE RANGE FOR
TODAY...BUT KEPT IT GOING TO THE WEST WHERE MORNING SUNSHINE WILL
PRODUCE THOSE STEEPER LAPSE RATES. CAN NOT COMPLETELY RULE OUT
SOME ELEVATED CONVECTION WITH LIGHTNING EVEN EAST OF THE LARAMIE
RANGE AS THE NORTHERN FRINGES OF AN UPPER LEVEL DISTURBANCE WILL
IMPACT THE SOUTHERN CWA...BUT WITH ONLY WEAK FORCING...LIGHTNING
CHANCES ARE REMOTE AT BEST. GUSTY WINDS AND SMALL GRAUPLE
CERTAINLY A POSSIBILITY WEST OF THE LARAMIE RANGE WITH ANY
STRONGER CONVECTION...BUT SEVERE THUNDERSTORMS NOT LIKELY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)

ISSUED AT 256 AM MDT SAT APR 19 2014

AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA THIS
AFTERNOON...WITH SURFACE WINDS VEERING TO THE SOUTHEAST ACROSS THE
PLAINS AND INCREASING IN STRENGTH. DEW POINTS WILL INCREASE INTO THE
UPPER 30S TO LOW 40S ACROSS THE PLAINS IN THIS MOISTURE ADVECTION
PATTERN WITH WEAK INSTABILITY PROGGED FOR THE AFTERNOON. HIGH CLOUD
COVER WILL KEEP TEMPS ON THE COOL SIDE AND THUS INSTABILITY WILL
BE LOW...BUT THE COMBO OF UPPER SUPPORT AND WEAK INSTABILITY WILL
SUPPORT A GOOD CHANCE FOR RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON ESPECIALLY FOR THE MOUNTAINS AND NEARBY PLAINS.
LOOKS AS THOUGH AREAS FROM THE LARAMIE RANGE TO THE I-25 CORRIDOR
COULD SEE THE BEST CHANCE FOR STORMS OUTSIDE THE MOUNTAINS WHERE
NAM PAINTS INSTABILITY AS HIGH AS 200 J/KG WITHIN THE
BEST...ALBEIT RELATIVELY WEAK...MOISTURE CONVERGENCE ZONE. SHOULD
SEE WETTING RAINS WITH THIS ACTIVITY AS PRECIPITABLE WATER VALUES
WILL INCREASE TO BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH
THROUGH THE AFTERNOON. CONVECTION WILL DIMINISH THROUGH THE
EVENING AS THE UPPER WAVE WEAKENS AND MOVES EAST.

FOR SUNDAY...A COLD FRONT ASSOCIATED WITH A SHORTWAVE MOVING ACROSS
US/CANADIAN BORDER WILL DROP SOUTH ACROSS THE EASTERN PLAINS IN THE
AFTERNOON. TEMPS WILL WARM INTO THE UPPER 60S TO UPPER 70S IN THE
LOWER ELEVATIONS AHEAD OF THE FRONT...WITH LI`S DROPPING TO AROUND
ZERO. TIMING OF THE FRONT COULD FAVOR DEVELOPMENT OF AFTERNOON
SHOWERS AND A FEW WEAK THUNDERSTORMS...ESPECIALLY ALONG THE LARAMIE
RANGE AND CHEYENNE RIDGE WHERE LLVL FORCING AND INSTABILITY ARE
MAXIMIZED. A WEAK DISTURBANCE MOVING OVERHEAD FROM THE WEST WILL
TRIGGER A FEW TSTORMS OVER THE MOUNTAINS IN THE AFTERNOON AS WELL.

SFC HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR MONDAY WITH MAX
TEMPS EXPECTED TO BE ABOUT 5F COOLER. SFC WINDS WILL VEER BACK TO
THE SOUTH-SOUTHEAST IN THE AFTERNOON AND SO MAY SEE A FEW RAIN
SHOWERS DEVELOP WITHIN THE CONVERGENCE ZONE VCTY LARAMIE RANGE. COOLER
SFC TEMPS AND WAA ALOFT DUE TO A BUILDING UPPER RIDGE FROM THE WEST
WILL MINIMIZE INSTABILITY AND THUS TSTORM CHANCES.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MDT SAT APR 19 2014

PRETTY STRONG LOW PRESSURE SYSTEM IN THE EXTENDED EXPECTED TO
BRING VERY STRONG WINDS AND SOME PRECIP CHANCES TO THE CWFA. THESE
ARE THE CHALLENGES IN THE LONG TERM.

FOR MONDAY NIGHT INTO TUESDAY...UPPER LEVEL RIDGING BUILDS INTO
THE AREA WITH 700MB TEMPERATURES CLIMBING FROM +4C MONDAY
AFTERNOON UP TO +8C TUESDAY AFTERNOON. LOOKS LIKE A PRETTY WARM
DAY TUESDAY WITH 80S RETURNING TO THE PANHANDLE AND UPPER 60S/LOW
70S FOR AREAS WEST OF THE LARAMIE RANGE.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO SOUTHERN
NEVADA TO NORTHERN UTAH TUESDAY AFTERNOON...THEN INTO WESTERN
WYOMING TUESDAY NIGHT. AHEAD OF THIS LOW...700MB WINDS BECOME
QUITE STRONG WITH THE GFS SHOW 50KTS AT 700MBS WEDNESDAY MORNING.
700MB CRAIG TO CASPER HEIGHT GRADIENT AT 60MTRS TUESDAY NIGHT AND
INCREASES TO 70MTRS DURING THE MORNING WEDNESDAY. WILL NEED TO
MONITOR THIS FOR POSSIBLE WIND HEADLINES DURING THIS
TIME FRAME...AT LEAST FOR OUR WIND PRONE AREAS.

COLD FRONT ASSOCIATED WITH THIS LOW LOOKS TO MOVE INTO THE AREA
WEDNESDAY AFTERNOON WITH 700MB TEMPERATURES FALLING TO -6C ACROSS
CARBON COUNTY WEDNESDAY NIGHT. FOR NOW...BEST CHANCES FOR PRECIP
LOOK TO BE THE MOUNTAINS AND AREAS WEST OF THE LARAMIE RANGE.
AREAS EAST WILL BE IMPACTED BY DOWNSLOPING WINDS...SO KEPT THESE
AREAS DRY.

CONCERNS FOR WIND HEADLINES SHIFTS EAST INTO THE PANHANDLE
WEDNESDAY NIGHT AS GFS 850MB WINDS INCREASE TO 40KTS. SHOULD BE AT
LEAST WIND ADVISORY CRITERIA OUT THERE...CONTINUING INTO THURSDAY
AFTERNOON.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 506 AM MDT SAT APR 19 2014

CONFIDENCE A LITTLE HIGHER FOR TSTMS TO DEVELOP ACROSS SOUTHERN
WYOMING AND THE SOUTHERN PANHANDLE THIS AFTERNOON AND EVENING.
LATEST HRRR FORECAST SHOWING CONVECTION DEVELOPING AS EARLY AS 18Z
AND PERSISTING THROUGH 00Z FOR KCYS AND KRWL. FOLLOWED THIS
GUIDANCE IN TAFS. CONVECTION COULD MAKE IT TO KBFF AFTER 00Z...BUT
WILL HOLD OFF FOR NOW ON TSTMS.


&&

.FIRE WEATHER...
ISSUED AT 256 AM MDT SAT APR 19 2014

TEMPERATURES WILL BE COOLER TODAY WITH HIGHER HUMIDITIES AND LESS
WIND. CHANCES FOR WETTING RAINS AND ISOLATED THUNDERSTORMS WILL
INCREASE THIS AFTERNOON AND WILL CONTINUE THROUGH THE EVENING AS A
WEATHER DISTURBANCE TRACKS ACROSS THE REGION. ANOTHER COLD FRONT
WILL DROP SOUTH ACROSS THE AREA ON SUNDAY AND WILL BRING A SLIGHT
CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE
MOUNTAINS AND AREAS NEAR THE COLORADO BORDER. AFTER A COOLER DAY
MONDAY...EXPECT WARMER AND DRIER CONDITIONS FOR TUESDAY WITH WINDY
CONDITIONS POSSIBLE FOR WEDNESDAY.

&&

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

$$

UPDATE...SML
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...RJM







000
FXUS65 KCYS 191109
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
509 AM MDT SAT APR 19 2014

.SHORT TERM...(TODAY THROUGH MONDAY)

ISSUED AT 256 AM MDT SAT APR 19 2014

AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA THIS
AFTERNOON...WITH SURFACE WINDS VEERING TO THE SOUTHEAST ACROSS THE
PLAINS AND INCREASING IN STRENGTH. DEW POINTS WILL INCREASE INTO THE
UPPER 30S TO LOW 40S ACROSS THE PLAINS IN THIS MOISTURE ADVECTION
PATTERN WITH WEAK INSTABILITY PROGGED FOR THE AFTERNOON. HIGH CLOUD
COVER WILL KEEP TEMPS ON THE COOL SIDE AND THUS INSTABILITY WILL
BE LOW...BUT THE COMBO OF UPPER SUPPORT AND WEAK INSTABILITY WILL
SUPPORT A GOOD CHANCE FOR RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON ESPECIALLY FOR THE MOUNTAINS AND NEARBY PLAINS.
LOOKS AS THOUGH AREAS FROM THE LARAMIE RANGE TO THE I-25 CORRIDOR
COULD SEE THE BEST CHANCE FOR STORMS OUTSIDE THE MOUNTAINS WHERE
NAM PAINTS INSTABILITY AS HIGH AS 200 J/KG WITHIN THE
BEST...ALBEIT RELATIVELY WEAK...MOISTURE CONVERGENCE ZONE. SHOULD
SEE WETTING RAINS WITH THIS ACTIVITY AS PRECIPITABLE WATER VALUES
WILL INCREASE TO BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH
THROUGH THE AFTERNOON. CONVECTION WILL DIMINISH THROUGH THE
EVENING AS THE UPPER WAVE WEAKENS AND MOVES EAST.

FOR SUNDAY...A COLD FRONT ASSOCIATED WITH A SHORTWAVE MOVING ACROSS
US/CANADIAN BORDER WILL DROP SOUTH ACROSS THE EASTERN PLAINS IN THE
AFTERNOON. TEMPS WILL WARM INTO THE UPPER 60S TO UPPER 70S IN THE
LOWER ELEVATIONS AHEAD OF THE FRONT...WITH LI`S DROPPING TO AROUND
ZERO. TIMING OF THE FRONT COULD FAVOR DEVELOPMENT OF AFTERNOON
SHOWERS AND A FEW WEAK THUNDERSTORMS...ESPECIALLY ALONG THE LARAMIE
RANGE AND CHEYENNE RIDGE WHERE LLVL FORCING AND INSTABILITY ARE
MAXIMIZED. A WEAK DISTURBANCE MOVING OVERHEAD FROM THE WEST WILL
TRIGGER A FEW TSTORMS OVER THE MOUNTAINS IN THE AFTERNOON AS WELL.

SFC HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR MONDAY WITH MAX
TEMPS EXPECTED TO BE ABOUT 5F COOLER. SFC WINDS WILL VEER BACK TO
THE SOUTH-SOUTHEAST IN THE AFTERNOON AND SO MAY SEE A FEW RAIN
SHOWERS DEVELOP WITHIN THE CONVERGENCE ZONE VCTY LARAMIE RANGE. COOLER
SFC TEMPS AND WAA ALOFT DUE TO A BUILDING UPPER RIDGE FROM THE WEST
WILL MINIMIZE INSTABILITY AND THUS TSTORM CHANCES.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MDT SAT APR 19 2014

PRETTY STRONG LOW PRESSURE SYSTEM IN THE EXTENDED EXPECTED TO
BRING VERY STRONG WINDS AND SOME PRECIP CHANCES TO THE CWFA. THESE
ARE THE CHALLENGES IN THE LONG TERM.

FOR MONDAY NIGHT INTO TUESDAY...UPPER LEVEL RIDGING BUILDS INTO
THE AREA WITH 700MB TEMPERATURES CLIMBING FROM +4C MONDAY
AFTERNOON UP TO +8C TUESDAY AFTERNOON. LOOKS LIKE A PRETTY WARM
DAY TUESDAY WITH 80S RETURNING TO THE PANHANDLE AND UPPER 60S/LOW
70S FOR AREAS WEST OF THE LARAMIE RANGE.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO SOUTHERN
NEVADA TO NORTHERN UTAH TUESDAY AFTERNOON...THEN INTO WESTERN
WYOMING TUESDAY NIGHT. AHEAD OF THIS LOW...700MB WINDS BECOME
QUITE STRONG WITH THE GFS SHOW 50KTS AT 700MBS WEDNESDAY MORNING.
700MB CRAIG TO CASPER HEIGHT GRADIENT AT 60MTRS TUESDAY NIGHT AND
INCREASES TO 70MTRS DURING THE MORNING WEDNESDAY. WILL NEED TO
MONITOR THIS FOR POSSIBLE WIND HEADLINES DURING THIS
TIME FRAME...AT LEAST FOR OUR WIND PRONE AREAS.

COLD FRONT ASSOCIATED WITH THIS LOW LOOKS TO MOVE INTO THE AREA
WEDNESDAY AFTERNOON WITH 700MB TEMPERATURES FALLING TO -6C ACROSS
CARBON COUNTY WEDNESDAY NIGHT. FOR NOW...BEST CHANCES FOR PRECIP
LOOK TO BE THE MOUNTAINS AND AREAS WEST OF THE LARAMIE RANGE.
AREAS EAST WILL BE IMPACTED BY DOWNSLOPING WINDS...SO KEPT THESE
AREAS DRY.

CONCERNS FOR WIND HEADLINES SHIFTS EAST INTO THE PANHANDLE
WEDNESDAY NIGHT AS GFS 850MB WINDS INCREASE TO 40KTS. SHOULD BE AT
LEAST WIND ADVISORY CRITERIA OUT THERE...CONTINUING INTO THURSDAY
AFTERNOON.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 506 AM MDT SAT APR 19 2014

CONFIDENCE A LITTLE HIGHER FOR TSTMS TO DEVELOP ACROSS SOUTHERN
WYOMING AND THE SOUTHERN PANHANDLE THIS AFTERNOON AND EVENING.
LATEST HRRR FORECAST SHOWING CONVECTION DEVELOPING AS EARLY AS 18Z
AND PERSISTING THROUGH 00Z FOR KCYS AND KRWL. FOLLOWED THIS
GUIDANCE IN TAFS. CONVECTION COULD MAKE IT TO KBFF AFTER 00Z...BUT
WILL HOLD OFF FOR NOW ON TSTMS.

&&

.FIRE WEATHER...
ISSUED AT 256 AM MDT SAT APR 19 2014

TEMPERATURES WILL BE COOLER TODAY WITH HIGHER HUMIDITIES AND LESS
WIND. CHANCES FOR WETTING RAINS AND ISOLATED THUNDERSTORMS WILL
INCREASE THIS AFTERNOON AND WILL CONTINUE THROUGH THE EVENING AS A
WEATHER DISTURBANCE TRACKS ACROSS THE REGION. ANOTHER COLD FRONT
WILL DROP SOUTH ACROSS THE AREA ON SUNDAY AND WILL BRING A SLIGHT
CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE
MOUNTAINS AND AREAS NEAR THE COLORADO BORDER. AFTER A COOLER DAY
MONDAY...EXPECT WARMER AND DRIER CONDITIONS FOR TUESDAY WITH WINDY
CONDITIONS POSSIBLE FOR WEDNESDAY.

&&

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

$$

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







000
FXUS65 KRIW 190941
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
341 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY STILL SHOWS PROGRESSIVE/FAST MOVING NRN BRANCH OF POLAR
FLOW ATOP SOMEWHAT SLOWER SRN BRANCH OF SUB-TROPICAL FLOW STRETCHING
ACROSS THE ENTIRE CONUS. THERE ARE NO LESS THAN 5 ACTIVE UPR LOWS
ENCOMPASSING THE CONUS...WITH EACH TRYING TO STEAL SOME THUNDER FROM
THE OTHER...KEEP ALL IN CHECK FOR THE MOST PART. HERE...UPR TROF
THRU WITH A COUPLE OF MOSTLY DRY FRONTS DRAPED ACROSS THE SRN AND
NRN FA. BENIGN HIGH PRESSURE WITH WEAK GRADIENT SLOWLY INFILTRATING
FROM THE NW...REIGNING IN THE WINDS FOR A WHILE ANYWAY.

GENERALLY...TODAY WILL BE SLIGHTLY COOLER THAN FRIDAY...WITH HIGH
TEMPS STILL REACHING INTO THE MIDDLE AND UPPER 60S FOR MOST OF THE
LOWER ELEVATIONS. OTHERWISE...NEARLY STATIONARY FRONT SET UP NEAR/
NORTH OF THE WY/CO BORDER IN OUR SRN MOST ZONES WILL AID IN RENEWED
CONVECTIVE DEVELOPMENT BY MID DAY IN A LARGELY DRY ADIABATIC
ATMOSPHERE. THIS AREA MAY LIFT FAR ENOUGH NORTH THAT SOME ACTIVITY
MAY PRESENT ITSELF OVR SRN NATRONA COUNTY TOO. WON`T HELP MUCH
HOWEVER AS CONVECTIVE MODE WILL HAVE LITTLE MOISTURE TO WORK
WITH...YIELDING MOSTLY DRY SHOWERS/STORMS WITH GUSTY WINDS.

SUNDAY WILL BE NICE OVERALL. THE AFTERNOON WILL OFFER LOW END
CHANCES FOR ISOLATED TO WIDELY SCATTERED SHOWERS WITH SOME THUNDER
AS A WEAK UPR LVL DISTURBANCE AND SFC FRONT RACE THROUGH THE FA.
TIMING AND MARGINALLY AVAILABLE MOISTURE WILL LIMIT THE CONVECTIVE
AREA TO OUR SRN AND SERN ZONES. HOWEVER...THIS WILL BE ANOTHER CASE
OF HIGH BASED SHOWERS/FEW STORMS WITH LITTLE RAIN...AND MORE GUSTY
WINDS. MONDAY THRU MOST OF THE DAY...UPR RIDGE AND STABLE ATMOSPHERE
IN PLACE. BY EVENING HOWEVER...RIDGE AXIS STARTS TO HEAD OUT WHILE
TROF FROM THE WEST BEGINS TO MOVE IN WITH PVA STARTING AS PART OF
POLAR JET...CURRENTLY HOVERING OVR THE EPAC REGION W OF
WA/OR...WORKS ITS WAY INTO THE WRN MOUNTAINS WITH A LITTLE MOISTURE.
THIS WILL HERALD THE BEGINNING OF NEW CYCLOGENESIS IN THE PAC NW
STATES THAT WILL AFFECT OUR CWA IN SOME RESPECT THROUGH THE MIDDLE
OF NEXT WEEK.

.LONG TERM...TUESDAY THROUGH SATURDAY

UPPER LOW ALONG THE EASTERN END OF THE ALEUTIANS EARLY THIS MORNING
WILL DIG INTO THE EASTERN PACIFIC AND MOVE ONTO THE WEST COAST
TUESDAY MORNING...WITH UPPER TROUGH LIFTING ACROSS THE ROCKIES ON
WEDNESDAY.  ASSOCIATED SURFACE COLD FRONT WILL SLOWLY MOVE EAST
ACROSS IDAHO TUESDAY...INTO THE WEST TUESDAY AFTERNOON...AND ACROSS
CENTRAL WYOMING TUESDAY NIGHT.  ECMWF AND GFS SPREAD INCREASES AS
THE UPPER TROUGH CROSSES THE DIVIDE...THE ECMWF REMAINS QUICKER
BUILDING A RIDGE IN BEHIND THE TROUGH ON THURSDAY WHILE THE GFS
KEEPS A COOL UNSETTLED NW FLOW OVER THE AREA...BEFORE BUILDING THE
RIDGE IN THURSDAY NIGHT.  OPERATIONAL ECMWF IS SLIGHTLY FASTER THAN
THE EC ENSEMBLE MEAN WHILE THE GFS OPERATIONAL IS SLIGHTLY SLOWER
AND DEEPER THAN ITS ENSEMBLE MEAN.  SPLITTING THE DIFFERENCE WOULD
PUT THE UPPER TROUGH AXIS ROUGHLY ALONG 100W BY 00Z FRIDAY AND THE
UPSTREAM RIDGE ALONG 115W...WITH THIS RIDGE TRANSLATING THE AREA ON
FRIDAY AS NEXT PACIFIC TROUGH PUSHES ONTO THE WEST COAST.

FOR SENSIBLE WEATHER...

ON TUESDAY...VERY MILD AND WINDY CONDITIONS WILL DEVELOP ACROSS
CENTRAL AREAS AS PACIFIC COLD FRONT PUSHES ACROSS IDAHO WITH
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS THE
WEST...SHOWERS AND ISOLATED STORMS SPREADING EAST LATE IN THE DAY.
SNOW LEVELS WILL REMAIN QUITE HIGH TUESDAY AHEAD OF THE
FRONT...GENERALLY AROUND 10KFT AND UP. RAPID SNOW MELT AND
SIGNIFICANT RISES IN CREEKS AND STREAMS WILL BE A CONCERN WITH THE
WARM TEMPERATURES...ESPECIALLY WITH THE POTENTIAL FOR RAIN NEAR
AND BELOW 10KFT.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...COLD FRONT WILL PUSH ACROSS THE
AREA SPREADING SHOWERS AND ISOLATED THUNDERSTORMS EAST OF THE DIVIDE
WITH SNOW LEVELS LOWERING TO THE VALLEY FLOORS IN THE WEST.  WNW
MOIST CYCLONIC FLOW ON BACKSIDE OF TROUGH LOOKS TO BRING SIGNIFICANT
SNOW ACCUMULATIONS FROM TETON...TOGWOTEE PASS NORTH TO YNP AND
THE BEARTOOTH PASS AREA WEDNESDAY AND WEDNESDAY NIGHT. GUSTY
DOWNSLOPE WEST WINDS WILL HINDER PRECIPITATION EAST OF THE DIVIDE
BEHIND THE COLD FRONT ON WEDNESDAY WITH THE BEST CHANCES OF RAIN
OR A RAIN AND SNOW MIX ACROSS THE NORTH AND SWEETWATER COUNTY.
HOWEVER...COLDER AND UNSTABLE NW FLOW PREVAIL BEHIND THE SYSTEM
WEDNESDAY NIGHT WITH SIGNIFICANT SNOW POSSIBLE IN THE BIGHORN
RANGE WITH POSSIBLY SOME HEAVIER CONVECTIVE SNOWBANDS FORMING IN
THE CENTRAL BASINS.

THURSDAY...FORECAST MAINTAINS CHANCES OF SNOW SHOWERS IN THE
NORTHERN MOUNTAINS WITH SLIGHT CHANCES OF RAIN/SNOW SHOWERS ACROSS
THE LOWER ELEVATIONS OF THE NORTH.  GUSTY W-NW WINDS AND SEASONABLY
COOL CONDITIONS OTHERWISE.

FRIDAY AND SATURDAY...WARMING TREND WITH BACKING SW FLOW AHEAD OF
NEXT PACIFIC TROUGH WITH INCREASING CHANCES OF SHOWERS IN THE
WEST...SLIGHT CHANCES OF SHOWERS EAST OF THE DIVIDE ON SATURDAY.


&&

.AVIATION.../12Z ISSUANCE/

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

THE EXTENT OF STRATUS IN WAKE OF A COLD FRONT OVER NATRONA
COUNTY...POSSIBLY IMPACTING KCPR...REMAINS IN QUESTION EARLY THIS
MORNING. WHETHER OR NOT TO KEEP THE BKN020 FOR KCPR WILL BE DECIDED
CLOSE TO THE 12Z TAF ISSUANCE TIME. HOWEVER...WHAT STRATUS DOES FORM
SHOULD LIFT OR SCATTER OUT BY AROUND 15Z. OTHERWISE...VFR CONDITIONS
WITH ONLY FEW-SCT HIGH CLOUDS AND MAINLY LIGHT WINDS ARE EXPECTED
THROUGH THE FORECAST PERIOD.

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

PATCHY FOG COULD OCCUR IN THE FAR WESTERN VALLEYS THIS MORNING WHERE
RAIN OCCURRED FRIDAY. OTHERWISE...THE MAIN AVIATION CONCERN WILL BE
THE POSSIBILITY OF ISOLATED CONVECTION SOUTH OF INTERSTATE 80. THIS
ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS TERMINAL...BUT THE TERMINAL
COULD SEE SOME OUTFLOW WINDS FROM THE ACTIVITY. OTHERWISE...VFR
CONDITIONS AND LIGHT WINDS ARE EXPECTED.

&&

.FIRE WEATHER...

TODAY...HIGH TEMPERATURES WILL BE WARM AND SEASONAL...WITH
MUCH LIGHTER WINDS THAN ON FRIDAY. ISOLATED CHANCES FOR MOSTLY DRY
SHOWERS OR AN ISOLATED THUNDERSTORM WILL BE POSSIBLE SOUTH OF A ROCK
SPRINGS TO CASPER LINE.  SUNDAY WILL BE SIMILAR IN MANY
RESPECTS...WITH HIGH TEMPERATURES A FEW DEGREES WARMER AND SLIGHT
CHANCES FOR SHOWERS A JUST BIT FURTHER NORTH. WINDS WILL BEGIN TO
SLOWLY INCREASE MONDAY NIGHT AS WILL CHANCES FOR PRECIPITATION IN
THE WESTERN MOUNTAIN ZONES...AS THE NEXT UPPER LEVEL DISTURBANCE
APPROACHES FROM THE WEST...HERALDING THE BEGINNING OF A COUPLE OF
DAYS OF PRECIPITATION OUT WEST. SIGNIFICANT MOUNTAIN SNOWS WILL BE
POSSIBLE STARTING TUESDAY NIGHT. OTHERWISE...WARM AND DRY ACROSS THE
CENTRAL AND SOUTHERN DISPATCH ZONES THROUGH TUESDAY NIGHT...WITH
WINDY CONDITIONS COMMENCING ACROSS ALL ZONES FROM TUESDAY NIGHT AND
LASTING THROUGH THURSDAY. THERE WILL BE SOME ENHANCED FIRE
DANGER...ESPECIALLY ON TUESDAY...AS THE WARMEST TEMPERATURE OF THE
SEASON COMBINE WITH THE STRONG WINDS. COOLER TEMPERATURES BOTH
WEDNESDAY AND THURSDAY WILL THEN MODERATE THE DANGER TO SOME
EXTENT.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...AEM
AVIATION...WM
FIRE WEATHER...BRAUN









000
FXUS63 KUNR 190915
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
315 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.

&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING
ISSUED AT 315 AM MDT SAT APR 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON







000
FXUS63 KUNR 190915
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
315 AM MDT SAT APR 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 315 AM MDT SAT APR 19 2014

CURRENT SURFACE ANALYSIS SHOWS COLD FRONT NOW JUST EAST OF THE
CWA...WITH MAIN AREA OF LOW PRESSURE NOW CENTERED OVER SOUTHEAST
ND. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE TROF AXIS OVER THE
WESTERN DAKOTAS...WITH JET STREAK OVER ND AND NORTHERN SD. SHOWERS
AND STORMS OVER PORTIONS OF THE AREA IN THE EVENING HAVE
DISSIPATED...WITH VARIABLY CLOUDY SKIES NOW IN PLACE. GUSTY
NORTHWEST WINDS REMAIN JUST BEHIND THE FRONT TOWARD CENTRAL
SD...BUT WILL DISSIPATE OVER THE NEXT COUPLE OF HOURS. TEMPS ARE
MOSTLY IN THE 40S AND LOWER 50S...WITH 30S OVER PORTIONS OF
NORTHEAST WY AND THE BLACK HILLS.

WARM WEATHER WILL CONTINUE THROUGH THE REST OF THE HOLIDAY
WEEKEND...THOUGH TODAY WILL BE THE COOLEST DAY OF THE STRETCH. HIGHS
WILL BE IN THE 60S TO AROUND 70 DEGREES TODAY...WARMEST TOWARD SOUTH
CENTRAL SD. 50S CAN BE EXPECTED ACROSS THE HIGHER BLACK HILLS.
NORTHWESTERLY WINDS WILL PERSIST...REMAINING BREEZY AT TIMES
ACROSS NORTHWESTERN SD. SKIES WILL BE CLEAR TO PARTLY CLOUDY
THROUGH THE WEEKEND. WARMER AIR WILL RETURN LATER TONIGHT AND
SUNDAY AS WINDS SHIFT TO THE SOUTH- SOUTHEAST. SUNDAY WILL SEE
TEMPERATURES SIMILAR TO YESTERDAY...WITH LESS WIND ACROSS THE
PLAINS. HIGHS WILL BE IN THE 70S TO NEAR 80 DEGREES. THE NEXT COOL
FRONT WILL PUSH INTO THE AREA IN THE AFTERNOON AND EVENING...
BRINGING BRISK NORTHWEST WINDS BEHIND IT. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS OF
SOUTHWEST AND SOUTH CENTRAL SD FOR LATER IN THE AFTERNOON AND
EVENING AS THE FRONT CROSSES. SHORT RANGE MODELS ARE IN PRETTY
GOOD AGREEMENT ON THIS POSSIBILITY...WITH LOW LEVEL MOISTURE AND
INSTABILITY LIKELY SUFFICIENT FOR ISOLATED ACTIVITY IN THESE
AREAS...THOUGH THE FORCING LOOKS TO BE RELATIVELY WEAK.

&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 315 AM MDT SAT APR 19 2014

AN UPPER LEVEL RIDGE WILL BRING PLEASANTLY WARM WEATHER TO THE
CWA MONDAY THROUGH TUESDAY AFTERNOON. MEDIUM RANGE GUIDANCE
CONTINUES TO SHOW UPPER LEVEL TROUGH MOVING THROUGH THE AREA
TUESDAY NIGHT THROUGH THURSDAY. LATEST RUNS SUGGEST SLIGHTLY
FASTER MOVEMENT TO THE SYSTEM WITH THE GFS FURTHEST NORTH WITH
UPPER LOW...ECMWF NOW SHOWS SYSTEM FURTHER SOUTH/BUT WRAPPING UP
FURTHER EAST COMPARED TO PREVIOUS RUNS. RESULT WILL BE INCREASING
CHANCES FOR PRECIPITATION TUESDAY NIGHT INTO THURSDAY AS WELL AS
INCREASING GRADIENT/WIND FOR WEDNESDAY/THURSDAY AS SURFACE LOW
DEVELOPS OVER THE DAKOTAS AND WRAPS UP OVER THE UPPER MIDWEST.
GENERAL CHANCE POPS STILL WARRANTED WITH TEMPERATURES COLD ENOUGH
AT NIGHT FOR A BIT OF SNOW IN THE HIGHER ELEVATIONS WEDNESDAY
NIGHT AND THEN ON THE PLAINS THURSDAY NIGHT.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING
ISSUED AT 315 AM MDT SAT APR 19 2014

VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...HELGESON






000
FXUS65 KCYS 190856
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
256 AM MDT SAT APR 19 2014

.SHORT TERM...(TODAY THROUGH MONDAY)

ISSUED AT 256 AM MDT SAT APR 19 2014

AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE FORECAST AREA THIS
AFTERNOON...WITH SURFACE WINDS VEERING TO THE SOUTHEAST ACROSS THE
PLAINS AND INCREASING IN STRENGTH. DEW POINTS WILL INCREASE INTO THE
UPPER 30S TO LOW 40S ACROSS THE PLAINS IN THIS MOISTURE ADVECTION
PATTERN WITH WEAK INSTABILITY PROGGED FOR THE AFTERNOON. HIGH CLOUD
COVER WILL KEEP TEMPS ON THE COOL SIDE AND THUS INSTABILITY WILL
BE LOW...BUT THE COMBO OF UPPER SUPPORT AND WEAK INSTABILITY WILL
SUPPORT A GOOD CHANCE FOR RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON ESPECIALLY FOR THE MOUNTAINS AND NEARBY PLAINS.
LOOKS AS THOUGH AREAS FROM THE LARAMIE RANGE TO THE I-25 CORRIDOR
COULD SEE THE BEST CHANCE FOR STORMS OUTSIDE THE MOUNTAINS WHERE
NAM PAINTS INSTABILITY AS HIGH AS 200 J/KG WITHIN THE
BEST...ALBEIT RELATIVELY WEAK...MOISTURE CONVERGENCE ZONE. SHOULD
SEE WETTING RAINS WITH THIS ACTIVITY AS PRECIPITABLE WATER VALUES
WILL INCREASE TO BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH
THROUGH THE AFTERNOON. CONVECTION WILL DIMINISH THROUGH THE
EVENING AS THE UPPER WAVE WEAKENS AND MOVES EAST.

FOR SUNDAY...A COLD FRONT ASSOCIATED WITH A SHORTWAVE MOVING ACROSS
US/CANADIAN BORDER WILL DROP SOUTH ACROSS THE EASTERN PLAINS IN THE
AFTERNOON. TEMPS WILL WARM INTO THE UPPER 60S TO UPPER 70S IN THE
LOWER ELEVATIONS AHEAD OF THE FRONT...WITH LI`S DROPPING TO AROUND
ZERO. TIMING OF THE FRONT COULD FAVOR DEVELOPMENT OF AFTERNOON
SHOWERS AND A FEW WEAK THUNDERSTORMS...ESPECIALLY ALONG THE LARAMIE
RANGE AND CHEYENNE RIDGE WHERE LLVL FORCING AND INSTABILITY ARE
MAXIMIZED. A WEAK DISTURBANCE MOVING OVERHEAD FROM THE WEST WILL
TRIGGER A FEW TSTORMS OVER THE MOUNTAINS IN THE AFTERNOON AS WELL.

SFC HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR MONDAY WITH MAX
TEMPS EXPECTED TO BE ABOUT 5F COOLER. SFC WINDS WILL VEER BACK TO
THE SOUTH-SOUTHEAST IN THE AFTERNOON AND SO MAY SEE A FEW RAIN
SHOWERS DEVELOP WITHIN THE CONVERGENCE ZONE VCTY LARAMIE RANGE. COOLER
SFC TEMPS AND WAA ALOFT DUE TO A BUILDING UPPER RIDGE FROM THE WEST
WILL MINIMIZE INSTABILITY AND THUS TSTORM CHANCES.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MDT SAT APR 19 2014

PRETTY STRONG LOW PRESSURE SYSTEM IN THE EXTENDED EXPECTED TO
BRING VERY STRONG WINDS AND SOME PRECIP CHANCES TO THE CWFA. THESE
ARE THE CHALLENGES IN THE LONG TERM.

FOR MONDAY NIGHT INTO TUESDAY...UPPER LEVEL RIDGING BUILDS INTO
THE AREA WITH 700MB TEMPERATURES CLIMBING FROM +4C MONDAY
AFTERNOON UP TO +8C TUESDAY AFTERNOON. LOOKS LIKE A PRETTY WARM
DAY TUESDAY WITH 80S RETURNING TO THE PANHANDLE AND UPPER 60S/LOW
70S FOR AREAS WEST OF THE LARAMIE RANGE.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO SOUTHERN
NEVADA TO NORTHERN UTAH TUESDAY AFTERNOON...THEN INTO WESTERN
WYOMING TUESDAY NIGHT. AHEAD OF THIS LOW...700MB WINDS BECOME
QUITE STRONG WITH THE GFS SHOW 50KTS AT 700MBS WEDNESDAY MORNING.
700MB CRAIG TO CASPER HEIGHT GRADIENT AT 60MTRS TUESDAY NIGHT AND
INCREASES TO 70MTRS DURING THE MORNING WEDNESDAY. WILL NEED TO
MONITOR THIS FOR POSSIBLE WIND HEADLINES DURING THIS
TIME FRAME...AT LEAST FOR OUR WIND PRONE AREAS.

COLD FRONT ASSOCIATED WITH THIS LOW LOOKS TO MOVE INTO THE AREA
WEDNESDAY AFTERNOON WITH 700MB TEMPERATURES FALLING TO -6C ACROSS
CARBON COUNTY WEDNESDAY NIGHT. FOR NOW...BEST CHANCES FOR PRECIP
LOOK TO BE THE MOUNTAINS AND AREAS WEST OF THE LARAMIE RANGE.
AREAS EAST WILL BE IMPACTED BY DOWNSLOPING WINDS...SO KEPT THESE
AREAS DRY.

CONCERNS FOR WIND HEADLINES SHIFTS EAST INTO THE PANHANDLE
WEDNESDAY NIGHT AS GFS 850MB WINDS INCREASE TO 40KTS. SHOULD BE AT
LEAST WIND ADVISORY CRITERIA OUT THERE...CONTINUING INTO THURSDAY
AFTERNOON.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1150 PM MDT FRI APR 18 2014

INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS PORTIONS
OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AS LOW LEVEL MOISTURE
MOVES INTO THE AREA IN SOUTHEAST WINDS. FOR NOW...WENT WITH
VCTS/VCSH FORECAST FOR OUR SOUTHEAST WYOMING AIRPORTS. WILL TRY TO
NARROW DOWN SPECIFIC AIRPORTS AND TIMES ON UPCOMING TAFS.

&&

.FIRE WEATHER...
ISSUED AT 256 AM MDT SAT APR 19 2014

TEMPERATURES WILL BE COOLER TODAY WITH HIGHER HUMIDITIES AND LESS
WIND. CHANCES FOR WETTING RAINS AND ISOLATED THUNDERSTORMS WILL
INCREASE THIS AFTERNOON AND WILL CONTINUE THROUGH THE EVENING AS A
WEATHER DISTURBANCE TRACKS ACROSS THE REGION. ANOTHER COLD FRONT
WILL DROP SOUTH ACROSS THE AREA ON SUNDAY AND WILL BRING A SLIGHT
CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE
MOUNTAINS AND AREAS NEAR THE COLORADO BORDER. AFTER A COOLER DAY
MONDAY...EXPECT WARMER AND DRIER CONDITIONS FOR TUESDAY WITH WINDY
CONDITIONS POSSIBLE FOR WEDNESDAY.

&&

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

$$

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









000
FXUS65 KCYS 190554
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1154 PM MDT FRI APR 18 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 212 PM MDT FRI APR 18 2014

MAIN QUESTION THIS EVENING IS IF CONVECTION CAN ACTUALLY BE
SUSTAINED LATER THIS AFTERNOON/EARLY EVENING. THE CONVECTION WHICH
HAS DEVELOPED HAS QUICKLY DIED OFF AFTER FORMATION...SO BEGINNING TO
WONDER IF SHOWERS AND THUNDERSTORMS ARE WORTH MENTIONING AT THIS
POINT. CIRRUS DECK TODAY WAS LIKELY JUST ENOUGH TO INHIBIT
STRONGER SURFACE WARMING AND DEEPER CONVECTION DEVELOPMENT. ALSO
THE LOW AND MID LEVEL ARE ON THE DRY SIDE. VERY WELL MAY NEED TO
TAKE MOST SHOWER AND THUNDERSTORM MENTION OUT OF THE FORECAST IN
THE NEXT FEW HOURS IF NOTHING DEVELOPS.

OTHERWISE FOR TONIGHT INCREASING HIGH AND MID CLOUDS WITH MOISTURE
LIFTING OUT OF THE SOUTHWEST CONUS INTO SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE...WHILE A COLD FRONT WILL DROP SOUTHWARD OVER
EASTERN PORTIONS OF THE FORECAST AREA. COULD SEE A FEW SHOWERS IN
THE SNOWY AND SIERRA MADRE RANGES LATE TONIGHT BUT THAT WOULD BE
ABOUT IT. SLIGHTLY BETTER CHANCE FOR A FEW SHOWERS AND
THUNDERSTORMS TOMORROW AFTERNOON...MAINLY OVER THE SOUTHERN CWA AS
NORTHERN FRINGES OF AN UPPER LEVEL LOW LIFT INTO THE AREA. SEVERE
THUNDERSTORMS ARE NOT EXPECTED.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM MDT FRI APR 18 2014

MODELS IN REASONABLE AGREEMENT THROUGH NEXT WEEK. AN UPPER LEVEL
RIDGE WILL SETTLE OVER THE AREA ON MONDAY AFTER A WEAK UPPER LEVEL
DISTURBANCE MOVES ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS.
A WEAK BACK DOOR COLD FRONT WILL DRIFT SOUTHWARD ACROSS THE HIGH
PLAINS SUNDAY NIGHT AND MONDAY RESULTING IN SLIGHTLY COOLER
TEMPERATURES FOR THE DAY. TEMPERATURES WILL STILL BE NEAR OR
SLIGHTLY ABOVE NORMAL AND GENERALLY IN THE 60S TO NEAR 70.
MEANWHILE...A STRONG STORM SYSTEM WILL MOVE INTO THE PACIFIC
COASTLINE WITH THE MAIN UPPER LEVEL LOW LOCATED SOMEWHERE ACROSS
THE PACIFIC NORTHWEST TUESDAY NIGHT. THIS STORM WILL BEGIN TO
IMPACT THE FORECAST AREA ON TUESDAY WITH GUSTY WINDS...BUT
TEMPERATURES AHEAD OF THE PACIFIC COLD FRONT WILL INCREASE INTO
THE 70S ACROSS MOST AREAS AND NEAR 80 ACROSS PORTIONS OF THE
NE PANHANDLE.

FOR WEDNESDAY...MODELS SHOW THE DEEP UPPER LEVEL LOW MOVING
ACROSS THE NORTHERN AND CENTRAL ROCKY MOUNTAINS. THE EXACT
POSITION AND MOVEMENT OF THIS STORM IS STILL UNCERTAIN...BUT IT IS
TRENDING NORTHWARD AND SHOWS THE SYSTEM GRADUALLY BECOMING AN OPEN
WAVE. THE GFS...GEM AND ECMWF SHOW THE STORM NORTH OF THE
FORECAST AREA. ENSEMBLE FORECASTS SHOW THE SAME...SO IT SEEMS
UNLIKELY THERE WILL BE ANY TREND SOUTHWARD AND MORE SIGNIFICANT
IMPACTS FOR THE FORECAST AREA. HOWEVER...THE SYSTEM IS SEVERAL
DAYS AWAY FROM MOVING ONSHORE SO WILL HAVE A BETTER IDEA SOMETIME
LATE THIS WEEKEND AND EARLY NEXT WEEK. FOR NOW...KEPT POP BETWEEN
15 TO 30 PERCENT...HIGHEST FURTHER NORTH AND IN THE MOUNTAINS
WEDNESDAY NIGHT THROUGH THURSDAY. WEDNESDAY WILL BE TRICKY BECAUSE
OF FIRE WEATHER CONCERNS...UNLESS THE SYSTEM DIGS SOUTHWARD WHERE
MUCH COLDER TEMPERATURES...WIND...AND PRECIPITATION WILL BE THE
MAIN CONCERN. TRENDED DRIER FOR NOW GIVEN MODEL CONSENSUS. LOWERED
TEMPERATURES THURSDAY AND FRIDAY AS THE PACIFIC COLD FRONT MOVES
ACROSS THE REGION...WITH HIGHS AND LOWS NEAR OR SLIGHTLY BELOW
NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1150 PM MDT FRI APR 18 2014

INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS PORTIONS
OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AS LOW LEVEL MOISTURES
MOVES INTO THE AREA IN SOUTHEAST WINDS. FOR NOW...WENT WITH
VCTS/VCSH FORECAST FOR OUR SOUTHEAST WYOMING AIRPORTS. WILL TRY TO
NARROW DOWN SPECIFIC AIRPORTS AND TIMES ON UPCOMING TAFS.

&&

.FIRE WEATHER...
ISSUED AT 212 PM MDT FRI APR 18 2014

NEAR CRITICAL FIRE WEATHER CONDITIONS OVER FAR SOUTHEAST WYOMING
AND THE NEBRASKA PANHANDLE WILL IMPROVE THIS EVENING AS HUMIDITY
INCREASES. A COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MOVE
INTO SOUTHEAST WYOMING LATE TONIGHT...WITH WINDS SHIFTING TO THE
NORTHEAST AND TEMPERATURES COOLER FOR TOMORROW. INCREASING
CHANCES FOR WETTING RAINS AND MOUNTAIN SNOW SATURDAY NIGHT INTO
SUNDAY FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LOW
PRESSURE TRACKS ACROSS NORTHERN COLORADO.

&&

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

$$

SHORT TERM...SML
LONG TERM...TJT
AVIATION...CLAYCOMB
FIRE WEATHER...GARMON/SML







000
FXUS65 KRIW 190522
AFDRIW

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE RIVERTON WY
1122 PM MDT FRI APR 18 2014

.SHORT TERM...TONIGHT AND SATURDAY

STRONG COLD FRONT MOVING TO NEAR THE CONTINENTAL DIVIDE ATTM WITH
STRONG SW WINDS AHEAD OF IT AND COLDER RAIN AND SNOW SHOWERS BEHIND
IT. COLD ENOUGH IN THE STAR VALLEY FOR A QUICK CHANGEOVER TO SNOW
WITH UP TO A QUICK INCH REPORTED. JACKSON VALLEY STAYED RAIN WITH
RAINFALL AMOUNTS GENERALLY BETWEEN .15 AND .30 INCHES. WINDS ARE
SURFACING EAST OF THE DIVIDE IN MANY AREAS WITH WIND GUSTS OF 40 TO
50 MPH IN QUITE A FEW AREAS AND LOCALIZED GUSTS BETWEEN 55 AND 60
MPH. SOME AREAS WILL FLIRT WITH OR BRIEFLY TOUCH HIGH WIND THROUGH
00Z OR A LITTLE LATER IN THE CENTRAL ZONES. SPS IS COVERING THESE
AREAS. THERE WILL BE A FEW RAIN SHOWERS WITH FROPA EAST OF THE
DIVIDE BUT THEY WILL BE JUST ISOLATED IN MANY AREAS WITH THE DRY
AIRMASS AHEAD OF IT. THE NORTHERN ZONES HOWEVER...HAVE A LITTLE LOW
LEVEL MOISTURE TO WORK WITH SO A BETTER SHOT THERE ALONG WITH AN
ISOLATED THUNDERSTORM STILL POSSIBLE BUT NOT NECESSARILY LIKELY.
SECONDARY FRONT THAT DROPS DOWN BEHIND THE WEAKENING UPPER
LOW/SHORTWAVE TONIGHT WITH BOUNDARY LAYER MOISTENING UP QUITE A BIT
IN NATRONA COUNTY. COULD BE ENOUGH FOR LOW CLOUDS OR PATCHY FOG SO
INDICATED THIS IN THE FORECAST AROUND SUNRISE. AND WITH THE RECENT
RAIN AND SNOW OUT WEST...WILL ADD SOME LOW CLOUDS AND FOG TO THE
JACKSON AND STAR VALLEYS FOR LATER TONIGHT THROUGH 15Z SATURDAY. ON
SATURDAY...SOME CONVECTION IS POSSIBLE ACROSS SWEETWATER COUNTY AS
FRONT BOUNDARY STALLS OUT DOWN THERE AND THEN A LITTLE BIT OF
MOISTURE AND VERY WEAK FORCING IS PROVIDED FROM A SYSTEM WELL TO OUR
SOUTH. SCATTERED HIGHER TERRAIN SHOWERS ARE CERTAINLY A
POSSIBILITY...MORE ISOLATED ON THE RED DESERT FLOOR. TEMPERATURES
WILL NOT BE QUITE AS WARM TOMORROW EAST OF THE DIVIDE WHILE WEST OF
THE DIVIDE...THEY`LL ACTUALLY BE WARMER WITHOUT THE PCPN.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY NIGHT

THE REST OF THE WEEKEND INTO MONDAY REMAINS RELATIVELY QUIET...WITH
A WEAK COLD FRONT MOVING THROUGH THE AREA SUNDAY MORNING. ISOLATED
SHOWERS AND AN ISOLATED THUNDERSTORM WILL BE POSSIBLE ACROSS
SOUTHERN PORTIONS SUNDAY...WITH DRY CONDITIONS ON MONDAY.

A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN ROCKIES INTO
ALBERTA MONDAY...AND SLOWLY PROGRESS EASTWARD INTO THE HIGH PLAINS
TUESDAY...AS THE NEXT STORM SYSTEM FROM THE NORTH PACIFIC DIGS
SOUTHEASTWARD INTO NORTHERN CALIFORNIA AND THE GREAT BASIN. A
DUMBBELL LOW WILL FORM BY 12Z WEDNESDAY AND PROGRESS EASTWARD OVER
MONTANA...BEFORE EJECTING INTO THE NORTHERN PLAINS BY 18Z THURSDAY.
NORTHWEST FLOW ALOFT WILL OCCUR IN THE STORMS WAKE...AS A RIDGE OF
HIGH PRESSURE BUILDS BACK INTO THE AREA ON FRIDAY INTO SATURDAY. THE
12Z GFS AND ECMWF HAVE COME MORE IN LINE WITH EACH OTHER THAN
PREVIOUS RUNS. THIS IS A PROMISING SIGN FIVE DAYS OUT...SO WILL
CONTINUE TO MONITOR ANY CHANGES AS THE STORM APPROACHES SHORE.

ON TUESDAY...ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WILL ENTER
WESTERN PORTIONS EARLY TUESDAY MORNING...INCREASING THROUGH THE DAY.
ISOLATED THUNDERSTORMS WILL BE POSSIBLE BY THE AFTERNOON ACROSS MOST
OF THE AREA...WITH MOST OF THE PRECIPITATION OCCURRING ACROSS
WESTERN...SOUTHWESTERN AND NORTHERN PORTIONS. SOUTHWEST FLOW ALOFT
WILL CREATE GUSTY WINDS DURING THE DAY AHEAD OF THE COLD FRONT
ACROSS CENTRAL AND SOUTHERN PORTIONS...AND PUSHING AFTERNOON
TEMPERATURES EAST OF THE DIVIDE INTO THE 70S AND POSSIBLY LOWER
80S.

ON WEDNESDAY...SNOW WILL FALL TUESDAY NIGHT INTO WEDNESDAY MORNING
ACROSS THE WESTERN MOUNTAINS AND THE HIGHER ELEVATIONS OF THE
BIGHORN MOUNTAINS. RAIN WILL SLOWLY CHANGE OVER TO SNOW ACROSS THE
WESTERN VALLEYS AND BASINS...BECOMING ALL SNOW SHORTLY BEFORE DAWN.
A RAIN/SNOW MIX WILL RETURN TO THESE AREAS BY LATE MORNING THROUGH
THE REST OF THE DAY. RAIN/SNOW SHOWERS WILL ALSO OCCUR ACROSS
SOUTHERN PORTIONS THROUGH MID MORNING BEFORE CHANGING OVER TO ALL
RAIN. THE REST OF THE AREA CAN EXPECT ISOLATED TO SCATTERED RAIN
SHOWERS THROUGH THE DAY.

ON THURSDAY...SNOW WILL CONTINUE ACROSS THE WEST...WITH A FEW
RAIN/SNOW SHOWERS MIXED IN LATER IN THE DAY. SNOW WILL FALL ACROSS
SOUTHERN PORTIONS...BECOMING MORE ISOLATED AND CHANGING TO RAIN BY
THE AFTERNOON. OVERALL...CHANCES FOR PRECIPITATION BECOME MORE
ISOLATED THROUGHOUT THE DAY.

BY FRIDAY...LINGERING ISOLATED SHOWERS ACROSS THE WEST.
OTHERWISE...COOLER AND DRY CONDITIONS.

&&

.AVIATION.../06Z ISSUANCE/

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

BREEZY WINDS IN A FEW LOCATIONS RIGHT NOW WILL CONTINUE TO WEAKEN
OVERNIGHT. SOME STRATUS IS EXPECTED TO DEVELOP OVER PORTIONS OF
JOHNSON AND NATRONA COUNTY IN WAKE OF A COLD FRONT LATER
TONIGHT...BUT THE EXTENT REMAINS IN QUESTION. HIGH RESOLUTION MODELS
CONTINUE TO SHOW BOUNDARY LAYER MOISTENING UP TO SUPPORT LOW CLOUDS
BETWEEN 09Z AND 12Z. WILL KEEP BKN020 FOR KCPR TERMINAL BETWEEN 12Z
AND 15Z...AND LATER FORECASTS CAN NUDGE AS NEED.
HOWEVER...WHAT STRATUS DOES FORM SHOULD LIFT OR SCATTER OUT BY
AROUND 15Z. OTHERWISE...VFR CONDITIONS WITH ONLY FEW-SCT HIGH CLOUDS
AND MAINLY LIGHT WINDS ARE EXPECTED SATURDAY AND SATURDAY EVENING.

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

PATCHY FOG COULD OCCUR IN THE FAR WESTERN VALLEYS SATURDAY MORNING
WHERE RAIN OCCURRED YESTERDAY. OTHERWISE...THE MAIN AVIATION CONCERN
WILL BE THE POSSIBILITY OF ISOLATED CONVECTION SOUTH OF INTERSTATE
80 SATURDAY AFTERNOON. THIS ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS
TERMINAL...BUT THE TERMINAL COULD SEE SOME OUTFLOW WINDS FROM THE
ACTIVITY. OTHERWISE...VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED.

&&

.FIRE WEATHER...

A STRONG COLD FRONT WILL CONTINUE MOVING ACROSS CENTRAL WYOMING THIS
AFTERNOON WITH STRONG WEST TO SOUTHWEST WINDS OF 40 TO 50 MPH AND
ISOLATED TO WIDELY SCATTERED SHOWERS. THUNDERSTORMS...IF ANY...WILL
BE VERY ISOLATED AND MAINLY CONFINED TO THE NORTHEAST PART OF THE
DISTRICT. MOUNTAIN SNOW SHOWERS OUT WEST WILL DIMINISH AND RETREAT
TO THE HIGHER PEAKS WITH TIME TONIGHT. SATURDAY WILL NOT BE AS WINDY
BUT STILL BREEZY TO LOCALLY WINDY...ESPECIALLY THE MOUNTAIN AND
FOOTHILL AREAS. THERE WILL BE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN SWEETWATER COUNTY...ESPECIALLY SOUTH OF INTERSTATE
80 SATURDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...SKRBAC
LONG TERM...LAVOIE
AVIATION...WM
FIRE WEATHER...SKRBAC
















000
FXUS65 KRIW 190519
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1118 PM MDT FRI APR 18 2014

.SHORT TERM...TONIGHT AND SATURDAY

STRONG COLD FRONT MOVING TO NEAR THE CONTINENTAL DIVIDE ATTM WITH
STRONG SW WINDS AHEAD OF IT AND COLDER RAIN AND SNOW SHOWERS BEHIND
IT. COLD ENOUGH IN THE STAR VALLEY FOR A QUICK CHANGEOVER TO SNOW
WITH UP TO A QUICK INCH REPORTED. JACKSON VALLEY STAYED RAIN WITH
RAINFALL AMOUNTS GENERALLY BETWEEN .15 AND .30 INCHES. WINDS ARE
SURFACING EAST OF THE DIVIDE IN MANY AREAS WITH WIND GUSTS OF 40 TO
50 MPH IN QUITE A FEW AREAS AND LOCALIZED GUSTS BETWEEN 55 AND 60
MPH. SOME AREAS WILL FLIRT WITH OR BRIEFLY TOUCH HIGH WIND THROUGH
00Z OR A LITTLE LATER IN THE CENTRAL ZONES. SPS IS COVERING THESE
AREAS. THERE WILL BE A FEW RAIN SHOWERS WITH FROPA EAST OF THE
DIVIDE BUT THEY WILL BE JUST ISOLATED IN MANY AREAS WITH THE DRY
AIRMASS AHEAD OF IT. THE NORTHERN ZONES HOWEVER...HAVE A LITTLE LOW
LEVEL MOISTURE TO WORK WITH SO A BETTER SHOT THERE ALONG WITH AN
ISOLATED THUNDERSTORM STILL POSSIBLE BUT NOT NECESSARILY LIKELY.
SECONDARY FRONT THAT DROPS DOWN BEHIND THE WEAKENING UPPER
LOW/SHORTWAVE TONIGHT WITH BOUNDARY LAYER MOISTENING UP QUITE A BIT
IN NATRONA COUNTY. COULD BE ENOUGH FOR LOW CLOUDS OR PATCHY FOG SO
INDICATED THIS IN THE FORECAST AROUND SUNRISE. AND WITH THE RECENT
RAIN AND SNOW OUT WEST...WILL ADD SOME LOW CLOUDS AND FOG TO THE
JACKSON AND STAR VALLEYS FOR LATER TONIGHT THROUGH 15Z SATURDAY. ON
SATURDAY...SOME CONVECTION IS POSSIBLE ACROSS SWEETWATER COUNTY AS
FRONT BOUNDARY STALLS OUT DOWN THERE AND THEN A LITTLE BIT OF
MOISTURE AND VERY WEAK FORCING IS PROVIDED FROM A SYSTEM WELL TO OUR
SOUTH. SCATTERED HIGHER TERRAIN SHOWERS ARE CERTAINLY A
POSSIBILITY...MORE ISOLATED ON THE RED DESERT FLOOR. TEMPERATURES
WILL NOT BE QUITE AS WARM TOMORROW EAST OF THE DIVIDE WHILE WEST OF
THE DIVIDE...THEY`LL ACTUALLY BE WARMER WITHOUT THE PCPN.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY NIGHT

THE REST OF THE WEEKEND INTO MONDAY REMAINS RELATIVELY QUIET...WITH
A WEAK COLD FRONT MOVING THROUGH THE AREA SUNDAY MORNING. ISOLATED
SHOWERS AND AN ISOLATED THUNDERSTORM WILL BE POSSIBLE ACROSS
SOUTHERN PORTIONS SUNDAY...WITH DRY CONDITIONS ON MONDAY.

A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN ROCKIES INTO
ALBERTA MONDAY...AND SLOWLY PROGRESS EASTWARD INTO THE HIGH PLAINS
TUESDAY...AS THE NEXT STORM SYSTEM FROM THE NORTH PACIFIC DIGS
SOUTHEASTWARD INTO NORTHERN CALIFORNIA AND THE GREAT BASIN. A
DUMBBELL LOW WILL FORM BY 12Z WEDNESDAY AND PROGRESS EASTWARD OVER
MONTANA...BEFORE EJECTING INTO THE NORTHERN PLAINS BY 18Z THURSDAY.
NORTHWEST FLOW ALOFT WILL OCCUR IN THE STORMS WAKE...AS A RIDGE OF
HIGH PRESSURE BUILDS BACK INTO THE AREA ON FRIDAY INTO SATURDAY. THE
12Z GFS AND ECMWF HAVE COME MORE IN LINE WITH EACH OTHER THAN
PREVIOUS RUNS. THIS IS A PROMISING SIGN FIVE DAYS OUT...SO WILL
CONTINUE TO MONITOR ANY CHANGES AS THE STORM APPROACHES SHORE.

ON TUESDAY...ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WILL ENTER
WESTERN PORTIONS EARLY TUESDAY MORNING...INCREASING THROUGH THE DAY.
ISOLATED THUNDERSTORMS WILL BE POSSIBLE BY THE AFTERNOON ACROSS MOST
OF THE AREA...WITH MOST OF THE PRECIPITATION OCCURRING ACROSS
WESTERN...SOUTHWESTERN AND NORTHERN PORTIONS. SOUTHWEST FLOW ALOFT
WILL CREATE GUSTY WINDS DURING THE DAY AHEAD OF THE COLD FRONT
ACROSS CENTRAL AND SOUTHERN PORTIONS...AND PUSHING AFTERNOON
TEMPERATURES EAST OF THE DIVIDE INTO THE 70S AND POSSIBLY LOWER
80S.

ON WEDNESDAY...SNOW WILL FALL TUESDAY NIGHT INTO WEDNESDAY MORNING
ACROSS THE WESTERN MOUNTAINS AND THE HIGHER ELEVATIONS OF THE
BIGHORN MOUNTAINS. RAIN WILL SLOWLY CHANGE OVER TO SNOW ACROSS THE
WESTERN VALLEYS AND BASINS...BECOMING ALL SNOW SHORTLY BEFORE DAWN.
A RAIN/SNOW MIX WILL RETURN TO THESE AREAS BY LATE MORNING THROUGH
THE REST OF THE DAY. RAIN/SNOW SHOWERS WILL ALSO OCCUR ACROSS
SOUTHERN PORTIONS THROUGH MID MORNING BEFORE CHANGING OVER TO ALL
RAIN. THE REST OF THE AREA CAN EXPECT ISOLATED TO SCATTERED RAIN
SHOWERS THROUGH THE DAY.

ON THURSDAY...SNOW WILL CONTINUE ACROSS THE WEST...WITH A FEW
RAIN/SNOW SHOWERS MIXED IN LATER IN THE DAY. SNOW WILL FALL ACROSS
SOUTHERN PORTIONS...BECOMING MORE ISOLATED AND CHANGING TO RAIN BY
THE AFTERNOON. OVERALL...CHANCES FOR PRECIPITATION BECOME MORE
ISOLATED THROUGHOUT THE DAY.

BY FRIDAY...LINGERING ISOLATED SHOWERS ACROSS THE WEST.
OTHERWISE...COOLER AND DRY CONDITIONS.

&&

.AVIATION.../06Z ISSUANCE/

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

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

BREEZY WINDS IN A FEW LOCATIONS RIGHT NOW WILL CONTINUE TO WEAKEN
OVERNIGHT. SOME STRATUS IS EXPECTED TO DEVELOP OVER PORTIONS OF
JOHNSON AND NATRONA COUNTY IN WAKE OF A COLD FRONT LATER
TONIGHT...BUT THE EXTENT REMAINS IN QUESTION. HIGH RESOLUTION MODELS
CONTINUE TO SHOW BOUNDARY LAYER MOISTENING UP TO SUPPORT LOW CLOUDS
BETWEEN 09Z AND 12Z. WILL KEEP BKN020 FOR KCPR TERMINAL BETWEEN 12Z
AND 15Z...AND LATER FORECASTS CAN NUDGE AS NEED.
HOWEVER...WHAT STRATUS DOES FORM SHOULD LIFT OR SCATTER OUT BY
AROUND 15Z. OTHERWISE...VFR CONDITIONS WITH ONLY FEW-SCT HIGH CLOUDS
AND MAINLY LIGHT WINDS ARE EXPECTED SATURDAY AND SATURDAY EVENING.

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

PATCHY FOG COULD OCCUR IN THE FAR WESTERN VALLEYS SATURDAY MORNING
WHERE RAIN OCCURRED YESTERDAY. OTHERWISE...THE MAIN AVIATION CONCERN
WILL BE THE POSSIBILITY OF ISOLATED CONVECTION SOUTH OF INTERSTATE
80 SATURDAY AFTERNOON. THIS ACTIVITY SHOULD REMAIN SOUTH OF THE KRKS
TERMINAL...BUT THE TERMINAL COULD SEE SOME OUTFLOW WINDS FROM THE
ACTIVITY. OTHERWISE...VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED.

&&

.FIRE WEATHER...

A STRONG COLD FRONT WILL CONTINUE MOVING ACROSS CENTRAL WYOMING THIS
AFTERNOON WITH STRONG WEST TO SOUTHWEST WINDS OF 40 TO 50 MPH AND
ISOLATED TO WIDELY SCATTERED SHOWERS. THUNDERSTORMS...IF ANY...WILL
BE VERY ISOLATED AND MAINLY CONFINED TO THE NORTHEAST PART OF THE
DISTRICT. MOUNTAIN SNOW SHOWERS OUT WEST WILL DIMINISH AND RETREAT
TO THE HIGHER PEAKS WITH TIME TONIGHT. SATURDAY WILL NOT BE AS WINDY
BUT STILL BREEZY TO LOCALLY WINDY...ESPECIALLY THE MOUNTAIN AND
FOOTHILL AREAS. THERE WILL BE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN SWEETWATER COUNTY...ESPECIALLY SOUTH OF INTERSTATE
80 SATURDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...SKRBAC
LONG TERM...LAVOIE
AVIATION...WM
FIRE WEATHER...SKRBAC













000
FXUS63 KUNR 190515
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1049 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THROUGH EARLY MORNING...ESP ACROSS THE NW SOUTH DAKOTA
PLAINS AND IN THE LEE OF THE BLACK HILLS. VFR CONDITIONS WILL
PREVAIL ACROSS MOST OF THE FA THROUGH THE PERIOD...SAVE FOR A
PATCH OF MVFR CIGS ACROSS NE WY AND FAR NW SD EARLY THIS MORNING.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...JC







000
FXUS63 KUNR 190515
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1049 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THROUGH EARLY MORNING...ESP ACROSS THE NW SOUTH DAKOTA
PLAINS AND IN THE LEE OF THE BLACK HILLS. VFR CONDITIONS WILL
PREVAIL ACROSS MOST OF THE FA THROUGH THE PERIOD...SAVE FOR A
PATCH OF MVFR CIGS ACROSS NE WY AND FAR NW SD EARLY THIS MORNING.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...JC







000
FXUS63 KUNR 190515
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1049 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THROUGH EARLY MORNING...ESP ACROSS THE NW SOUTH DAKOTA
PLAINS AND IN THE LEE OF THE BLACK HILLS. VFR CONDITIONS WILL
PREVAIL ACROSS MOST OF THE FA THROUGH THE PERIOD...SAVE FOR A
PATCH OF MVFR CIGS ACROSS NE WY AND FAR NW SD EARLY THIS MORNING.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...JC







000
FXUS63 KUNR 190515
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1049 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THROUGH EARLY MORNING...ESP ACROSS THE NW SOUTH DAKOTA
PLAINS AND IN THE LEE OF THE BLACK HILLS. VFR CONDITIONS WILL
PREVAIL ACROSS MOST OF THE FA THROUGH THE PERIOD...SAVE FOR A
PATCH OF MVFR CIGS ACROSS NE WY AND FAR NW SD EARLY THIS MORNING.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...JC







000
FXUS65 KCYS 182356
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
556 PM MDT FRI APR 18 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 212 PM MDT FRI APR 18 2014

MAIN QUESTION THIS EVENING IS IF CONVECTION CAN ACTUALLY BE
SUSTAINED LATER THIS AFTERNOON/EARLY EVENING. THE CONVECTION WHICH
HAS DEVELOPED HAS QUICKLY DIED OFF AFTER FORMATION...SO BEGINNING TO
WONDER IF SHOWERS AND THUNDERSTORMS ARE WORTH MENTIONING AT THIS
POINT. CIRRUS DECK TODAY WAS LIKELY JUST ENOUGH TO INHIBIT
STRONGER SURFACE WARMING AND DEEPER CONVECTION DEVELOPMENT. ALSO
THE LOW AND MID LEVEL ARE ON THE DRY SIDE. VERY WELL MAY NEED TO
TAKE MOST SHOWER AND THUNDERSTORM MENTION OUT OF THE FORECAST IN
THE NEXT FEW HOURS IF NOTHING DEVELOPS.

OTHERWISE FOR TONIGHT INCREASING HIGH AND MID CLOUDS WITH MOISTURE
LIFTING OUT OF THE SOUTHWEST CONUS INTO SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE...WHILE A COLD FRONT WILL DROP SOUTHWARD OVER
EASTERN PORTIONS OF THE FORECAST AREA. COULD SEE A FEW SHOWERS IN
THE SNOWY AND SIERRA MADRE RANGES LATE TONIGHT BUT THAT WOULD BE
ABOUT IT. SLIGHTLY BETTER CHANCE FOR A FEW SHOWERS AND
THUNDERSTORMS TOMORROW AFTERNOON...MAINLY OVER THE SOUTHERN CWA AS
NORTHERN FRINGES OF AN UPPER LEVEL LOW LIFT INTO THE AREA. SEVERE
THUNDERSTORMS ARE NOT EXPECTED.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM MDT FRI APR 18 2014

MODELS IN REASONABLE AGREEMENT THROUGH NEXT WEEK. AN UPPER LEVEL
RIDGE WILL SETTLE OVER THE AREA ON MONDAY AFTER A WEAK UPPER LEVEL
DISTURBANCE MOVES ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS.
A WEAK BACK DOOR COLD FRONT WILL DRIFT SOUTHWARD ACROSS THE HIGH
PLAINS SUNDAY NIGHT AND MONDAY RESULTING IN SLIGHTLY COOLER
TEMPERATURES FOR THE DAY. TEMPERATURES WILL STILL BE NEAR OR
SLIGHTLY ABOVE NORMAL AND GENERALLY IN THE 60S TO NEAR 70.
MEANWHILE...A STRONG STORM SYSTEM WILL MOVE INTO THE PACIFIC
COASTLINE WITH THE MAIN UPPER LEVEL LOW LOCATED SOMEWHERE ACROSS
THE PACIFIC NORTHWEST TUESDAY NIGHT. THIS STORM WILL BEGIN TO
IMPACT THE FORECAST AREA ON TUESDAY WITH GUSTY WINDS...BUT
TEMPERATURES AHEAD OF THE PACIFIC COLD FRONT WILL INCREASE INTO
THE 70S ACROSS MOST AREAS AND NEAR 80 ACROSS PORTIONS OF THE
NE PANHANDLE.

FOR WEDNESDAY...MODELS SHOW THE DEEP UPPER LEVEL LOW MOVING
ACROSS THE NORTHERN AND CENTRAL ROCKY MOUNTAINS. THE EXACT
POSITION AND MOVEMENT OF THIS STORM IS STILL UNCERTAIN...BUT IT IS
TRENDING NORTHWARD AND SHOWS THE SYSTEM GRADUALLY BECOMING AN OPEN
WAVE. THE GFS...GEM AND ECMWF SHOW THE STORM NORTH OF THE
FORECAST AREA. ENSEMBLE FORECASTS SHOW THE SAME...SO IT SEEMS
UNLIKELY THERE WILL BE ANY TREND SOUTHWARD AND MORE SIGNIFICANT
IMPACTS FOR THE FORECAST AREA. HOWEVER...THE SYSTEM IS SEVERAL
DAYS AWAY FROM MOVING ONSHORE SO WILL HAVE A BETTER IDEA SOMETIME
LATE THIS WEEKEND AND EARLY NEXT WEEK. FOR NOW...KEPT POP BETWEEN
15 TO 30 PERCENT...HIGHEST FURTHER NORTH AND IN THE MOUNTAINS
WEDNESDAY NIGHT THROUGH THURSDAY. WEDNESDAY WILL BE TRICKY BECAUSE
OF FIRE WEATHER CONCERNS...UNLESS THE SYSTEM DIGS SOUTHWARD WHERE
MUCH COLDER TEMPERATURES...WIND...AND PRECIPITATION WILL BE THE
MAIN CONCERN. TRENDED DRIER FOR NOW GIVEN MODEL CONSENSUS. LOWERED
TEMPERATURES THURSDAY AND FRIDAY AS THE PACIFIC COLD FRONT MOVES
ACROSS THE REGION...WITH HIGHS AND LOWS NEAR OR SLIGHTLY BELOW
NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 533 PM MDT FRI APR 18 2014
LATEST RADAR LOOP WAS SHOWING VIRGA SHOWERS TRYING TO GET GOING TO
THE EAST OF CHEYENNE. MAY SEE A FEW WIND GUSTS UNDERNEATH THESE
SHOWERS THIS EVENING. OTHERWISE...LOW PRESSURE IN WESTERN SOUTH
DAKOTA WITH A TRAILING FRONTAL BOUNDARY EXTENDING TO SOUTHWEST
THROUGH CONVERSE COUNTY SHOULD CONTINUE TO PUSH SOUTHEAST THIS
EVENING. THIS BOUNDARY SHOULD MOVE THROUGH CDR AND LAR TAF SITES
BY 03Z...CYS...AIA...BFF BETWEEN 04Z AND 07Z AND SNY BY 10Z. NOT
EXPECTING MUCH MORE THAN A WIND SHIFT BEHIND THIS BOUNDARY.
OTHERWISE...WE ARE LOOKING MORE INSTABILITY SHOWERS AND
THUNDERSTORMS DEVELOPING TOMORROW AFTERNOON MAINLY ACROSS
SOUTHEAST WYOMING.


&&

.FIRE WEATHER...
ISSUED AT 212 PM MDT FRI APR 18 2014

NEAR CRITICAL FIRE WEATHER CONDITIONS OVER FAR SOUTHEAST WYOMING
AND THE NEBRASKA PANHANDLE WILL IMPROVE THIS EVENING AS HUMIDITY
INCREASES. A COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MOVE
INTO SOUTHEAST WYOMING LATE TONIGHT...WITH WINDS SHIFTING TO THE
NORTHEAST AND TEMPERATURES COOLER FOR TOMORROW. INCREASING
CHANCES FOR WETTING RAINS AND MOUNTAIN SNOW SATURDAY NIGHT INTO
SUNDAY FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LOW
PRESSURE TRACKS ACROSS NORTHERN COLORADO.

&&

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

$$

SHORT TERM...SML
LONG TERM...TJT
AVIATION...REC/RAE
FIRE WEATHER...GARMON/SML








000
FXUS63 KUNR 182311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
511 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 508 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THIS EVENING...ESPECIALLY ACROSS THE SOUTH DAKOTA PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS MOST AREAS. THERE IS A CHANCE OF
TSRA THIS EVENING WITH LOCALIZED MVFR VSBYS.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...POJORLIE






000
FXUS63 KUNR 182311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
511 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 508 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THIS EVENING...ESPECIALLY ACROSS THE SOUTH DAKOTA PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS MOST AREAS. THERE IS A CHANCE OF
TSRA THIS EVENING WITH LOCALIZED MVFR VSBYS.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...POJORLIE






000
FXUS63 KUNR 182311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
511 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 508 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THIS EVENING...ESPECIALLY ACROSS THE SOUTH DAKOTA PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS MOST AREAS. THERE IS A CHANCE OF
TSRA THIS EVENING WITH LOCALIZED MVFR VSBYS.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...POJORLIE






000
FXUS63 KUNR 182311
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
511 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.



&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 508 PM MDT FRI APR 18 2014

GUSTY NORTHWESTERLY WINDS ARE EXPECTED BEHIND A COLD
FRONT THIS EVENING...ESPECIALLY ACROSS THE SOUTH DAKOTA PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS MOST AREAS. THERE IS A CHANCE OF
TSRA THIS EVENING WITH LOCALIZED MVFR VSBYS.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...POJORLIE






000
FXUS65 KCYS 182108
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
308 PM MDT FRI APR 18 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 212 PM MDT FRI APR 18 2014

MAIN QUESTION THIS EVENING IS IF CONVECTION CAN ACTUALLY BE
SUSTAINED LATER THIS AFTERNOON/EARLY EVENING. THE CONVECTION WHICH
HAS DEVELOPED HAS QUICKLY DIED OFF AFTER FORMATION...SO BEGINNING TO
WONDER IF SHOWERS AND THUNDERSTORMS ARE WORTH MENTIONING AT THIS
POINT. CIRRUS DECK TODAY WAS LIKELY JUST ENOUGH TO INHIBIT
STRONGER SURFACE WARMING AND DEEPER CONVECTION DEVELOPMENT. ALSO
THE LOW AND MID LEVEL ARE ON THE DRY SIDE. VERY WELL MAY NEED TO
TAKE MOST SHOWER AND THUNDERSTORM MENTION OUT OF THE FORECAST IN
THE NEXT FEW HOURS IF NOTHING DEVELOPS.

OTHERWISE FOR TONIGHT INCREASING HIGH AND MID CLOUDS WITH MOISTURE
LIFTING OUT OF THE SOUTHWEST CONUS INTO SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE...WHILE A COLD FRONT WILL DROP SOUTHWARD OVER
EASTERN PORTIONS OF THE FORECAST AREA. COULD SEE A FEW SHOWERS IN
THE SNOWY AND SIERRA MADRE RANGES LATE TONIGHT BUT THAT WOULD BE
ABOUT IT. SLIGHTLY BETTER CHANCE FOR A FEW SHOWERS AND
THUNDERSTORMS TOMORROW AFTERNOON...MAINLY OVER THE SOUTHERN CWA AS
NORTHERN FRINGES OF AN UPPER LEVEL LOW LIFT INTO THE AREA. SEVERE
THUNDERSTORMS ARE NOT EXPECTED.


.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM MDT FRI APR 18 2014

MODELS IN REASONABLE AGREEMENT THROUGH NEXT WEEK. AN UPPER LEVEL
RIDGE WILL SETTLE OVER THE AREA ON MONDAY AFTER A WEAK UPPER LEVEL
DISTURBANCE MOVES ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS.
A WEAK BACK DOOR COLD FRONT WILL DRIFT SOUTHWARD ACROSS THE HIGH
PLAINS SUNDAY NIGHT AND MONDAY RESULTING IN SLIGHTLY COOLER
TEMPERATURES FOR THE DAY. TEMPERATURES WILL STILL BE NEAR OR
SLIGHTLY ABOVE NORMAL AND GENERALLY IN THE 60S TO NEAR 70.
MEANWHILE...A STRONG STORM SYSTEM WILL MOVE INTO THE PACIFIC
COASTLINE WITH THE MAIN UPPER LEVEL LOW LOCATED SOMEWHERE ACROSS
THE PACIFIC NORTHWEST TUESDAY NIGHT. THIS STORM WILL BEGIN TO
IMPACT THE FORECAST AREA ON TUESDAY WITH GUSTY WINDS...BUT
TEMPERATURES AHEAD OF THE PACIFIC COLD FRONT WILL INCREASE INTO
THE 70S ACROSS MOST AREAS AND NEAR 80 ACROSS PORTIONS OF THE
NE PANHANDLE.

FOR WEDNESDAY...MODELS SHOW THE DEEP UPPER LEVEL LOW MOVING
ACROSS THE NORTHERN AND CENTRAL ROCKY MOUNTAINS. THE EXACT
POSITION AND MOVEMENT OF THIS STORM IS STILL UNCERTAIN...BUT IT IS
TRENDING NORTHWARD AND SHOWS THE SYSTEM GRADUALLY BECOMING AN OPEN
WAVE. THE GFS...GEM AND ECMWF SHOW THE STORM NORTH OF THE
FORECAST AREA. ENSEMBLE FORECASTS SHOW THE SAME...SO IT SEEMS
UNLIKELY THERE WILL BE ANY TREND SOUTHWARD AND MORE SIGNIFICANT
IMPACTS FOR THE FORECAST AREA. HOWEVER...THE SYSTEM IS SEVERAL
DAYS AWAY FROM MOVING ONSHORE SO WILL HAVE A BETTER IDEA SOMETIME
LATE THIS WEEKEND AND EARLY NEXT WEEK. FOR NOW...KEPT POP BETWEEN
15 TO 30 PERCENT...HIGHEST FURTHER NORTH AND IN THE MOUNTAINS
WEDNESDAY NIGHT THROUGH THURSDAY. WEDNESDAY WILL BE TRICKY BECAUSE
OF FIRE WEATHER CONCERNS...UNLESS THE SYSTEM DIGS SOUTHWARD WHERE
MUCH COLDER TEMPERATURES...WIND...AND PRECIPITATION WILL BE THE
MAIN CONCERN. TRENDED DRIER FOR NOW GIVEN MODEL CONSENSUS. LOWERED
TEMPERATURES THURSDAY AND FRIDAY AS THE PACIFIC COLD FRONT MOVES
ACROSS THE REGION...WITH HIGHS AND LOWS NEAR OR SLIGHTLY BELOW
NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)
ISSUED AT 1130 AM MDT FRI APR 18 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THERE IS A SLIGHT
CHANCE FOR TSTORMS THIS EVENING MAINLY AT KCDR AS A COLD FRONT
BEGINS TO DROP SOUTH THROUGH THE REGION...BUT PROBABILITIES ARE ONLY
AROUND 15 TO 20 PERCENT. OTHERWISE...THE MAIN ISSUE WILL BE GUSTY
SOUTHWEST WINDS CONTINUING THROUGH THIS EVENING UNTIL THE FRONTAL
PASSAGE. GUSTS BETWEEN 25 TO 40 KTS ARE EXPECTED AT ALL
TERMINALS...WITH THE HIGHEST WINDS AT KRWL. THE COLD WILL STEADILY
MOVE FROM NORTH TO SOUTH ACROSS THE EASTERN PLAINS BETWEEN 05 AND
10Z TONIGHT RESULTING IN WINDS SHIFTING INTO THE NORTH AND NORTHEAST.


&&

.FIRE WEATHER...
ISSUED AT 212 PM MDT FRI APR 18 2014

NEAR CRITICAL FIRE WEATHER CONDITIONS OVER FAR SOUTHEAST WYOMING
AND THE NEBRASKA PANHANDLE WILL IMPROVE THIS EVENING AS HUMIDITY
INCREASES. A COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MOVE
INTO SOUTHEAST WYOMING LATE TONIGHT...WITH WINDS SHIFTING TO THE
NORTHEAST AND TEMPERATURES COOLER FOR TOMORROW. INCREASING
CHANCES FOR WETTING RAINS AND MOUNTAIN SNOW SATURDAY NIGHT INTO
SUNDAY FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LOW
PRESSURE TRACKS ACROSS NORTHERN COLORADO.


&&

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

$$

SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...GARMON/SML









000
FXUS65 KRIW 182049
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
249 PM MDT FRI APR 18 2014

.SHORT TERM...TONIGHT AND SATURDAY

STRONG COLD FRONT MOVING TO NEAR THE CONTINENTAL DIVIDE ATTM WITH
STRONG SW WINDS AHEAD OF IT AND COLDER RAIN AND SNOW SHOWERS BEHIND
IT. COLD ENOUGH IN THE STAR VALLEY FOR A QUICK CHANGEOVER TO SNOW
WITH UP TO A QUICK INCH REPORTED. JACKSON VALLEY STAYED RAIN WITH
RAINFALL AMOUNTS GENERALLY BETWEEN .15 AND .30 INCHES. WINDS ARE
SURFACING EAST OF THE DIVIDE IN MANY AREAS WITH WIND GUSTS OF 40 TO
50 MPH IN QUITE A FEW AREAS AND LOCALIZED GUSTS BETWEEN 55 AND 60
MPH. SOME AREAS WILL FLIRT WITH OR BRIEFLY TOUCH HIGH WIND THROUGH
00Z OR A LITTLE LATER IN THE CENTRAL ZONES. SPS IS COVERING THESE
AREAS. THERE WILL BE A FEW RAIN SHOWERS WITH FROPA EAST OF THE
DIVIDE BUT THEY WILL BE JUST ISOLATED IN MANY AREAS WITH THE DRY
AIRMASS AHEAD OF IT. THE NORTHERN ZONES HOWEVER...HAVE A LITTLE LOW
LEVEL MOISTURE TO WORK WITH SO A BETTER SHOT THERE ALONG WITH AN
ISOLATED THUNDERSTORM STILL POSSIBLE BUT NOT NECESSARILY LIKELY.
SECONDARY FRONT THAT DROPS DOWN BEHIND THE WEAKENING UPPER
LOW/SHORTWAVE TONIGHT WITH BOUNDARY LAYER MOISTENING UP QUITE A BIT
IN NATRONA COUNTY. COULD BE ENOUGH FOR LOW CLOUDS OR PATCHY FOG SO
INDICATED THIS IN THE FORECAST AROUND SUNRISE. AND WITH THE RECENT
RAIN AND SNOW OUT WEST...WILL ADD SOME LOW CLOUDS AND FOG TO THE
JACKSON AND STAR VALLEYS FOR LATER TONIGHT THROUGH 15Z SATURDAY. ON
SATURDAY...SOME CONVECTION IS POSSIBLE ACROSS SWEETWATER COUNTY AS
FRONT BOUNDARY STALLS OUT DOWN THERE AND THEN A LITTLE BIT OF
MOISTURE AND VERY WEAK FORCING IS PROVIDED FROM A SYSTEM WELL TO OUR
SOUTH. SCATTERED HIGHER TERRAIN SHOWERS ARE CERTAINLY A
POSSIBILITY...MORE ISOLATED ON THE RED DESERT FLOOR. TEMPERATURES
WILL NOT BE QUITE AS WARM TOMORROW EAST OF THE DIVIDE WHILE WEST OF
THE DIVIDE...THEY`LL ACTUALLY BE WARMER WITHOUT THE PCPN.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY NIGHT

THE REST OF THE WEEKEND INTO MONDAY REMAINS RELATIVELY QUIET...WITH
A WEAK COLD FRONT MOVING THROUGH THE AREA SUNDAY MORNING. ISOLATED
SHOWERS AND AN ISOLATED THUNDERSTORM WILL BE POSSIBLE ACROSS
SOUTHERN PORTIONS SUNDAY...WITH DRY CONDITIONS ON MONDAY.

A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN ROCKIES INTO
ALBERTA MONDAY...AND SLOWLY PROGRESS EASTWARD INTO THE HIGH PLAINS
TUESDAY...AS THE NEXT STORM SYSTEM FROM THE NORTH PACIFIC DIGS
SOUTHEASTWARD INTO NORTHERN CALIFORNIA AND THE GREAT BASIN. A
DUMBBELL LOW WILL FORM BY 12Z WEDNESDAY AND PROGRESS EASTWARD OVER
MONTANA...BEFORE EJECTING INTO THE NORTHERN PLAINS BY 18Z THURSDAY.
NORTHWEST FLOW ALOFT WILL OCCUR IN THE STORMS WAKE...AS A RIDGE OF
HIGH PRESSURE BUILDS BACK INTO THE AREA ON FRIDAY INTO SATURDAY. THE
12Z GFS AND ECMWF HAVE COME MORE IN LINE WITH EACH OTHER THAN
PREVIOUS RUNS. THIS IS A PROMISING SIGN FIVE DAYS OUT...SO WILL
CONTINUE TO MONITOR ANY CHANGES AS THE STORM APPROACHES SHORE.

ON TUESDAY...ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WILL ENTER
WESTERN PORTIONS EARLY TUESDAY MORNING...INCREASING THROUGH THE DAY.
ISOLATED THUNDERSTORMS WILL BE POSSIBLE BY THE AFTERNOON ACROSS MOST
OF THE AREA...WITH MOST OF THE PRECIPITATION OCCURRING ACROSS
WESTERN...SOUTHWESTERN AND NORTHERN PORTIONS. SOUTHWEST FLOW ALOFT
WILL CREATE GUSTY WINDS DURING THE DAY AHEAD OF THE COLD FRONT
ACROSS CENTRAL AND SOUTHERN PORTIONS...AND PUSHING AFTERNOON
TEMPERATURES EAST OF THE DIVIDE INTO THE 70S AND POSSIBLY LOWER
80S.

ON WEDNESDAY...SNOW WILL FALL TUESDAY NIGHT INTO WEDNESDAY MORNING
ACROSS THE WESTERN MOUNTAINS AND THE HIGHER ELEVATIONS OF THE
BIGHORN MOUNTAINS. RAIN WILL SLOWLY CHANGE OVER TO SNOW ACROSS THE
WESTERN VALLEYS AND BASINS...BECOMING ALL SNOW SHORTLY BEFORE DAWN.
A RAIN/SNOW MIX WILL RETURN TO THESE AREAS BY LATE MORNING THROUGH
THE REST OF THE DAY. RAIN/SNOW SHOWERS WILL ALSO OCCUR ACROSS
SOUTHERN PORTIONS THROUGH MID MORNING BEFORE CHANGING OVER TO ALL
RAIN. THE REST OF THE AREA CAN EXPECT ISOLATED TO SCATTERED RAIN
SHOWERS THROUGH THE DAY.

ON THURSDAY...SNOW WILL CONTINUE ACROSS THE WEST...WITH A FEW
RAIN/SNOW SHOWERS MIXED IN LATER IN THE DAY. SNOW WILL FALL ACROSS
SOUTHERN PORTIONS...BECOMING MORE ISOLATED AND CHANGING TO RAIN BY
THE AFTERNOON. OVERALL...CHANCES FOR PRECIPITATION BECOME MORE
ISOLATED THROUGHOUT THE DAY.

BY FRIDAY...LINGERING ISOLATED SHOWERS ACROSS THE WEST.
OTHERWISE...COOLER AND DRY CONDITIONS.

&&

.AVIATION.../00Z ISSUANCE/

COLD FRONT WILL MOVE QUICKLY EAST OF THE DIVIDE THROUGH EVENING
HOURS WITH A LOT OF WIND AND A FEW SHOWERS AND EVEN AN ISOLATED
THUNDERSTORM POSSIBLE. SCATTERED MOUNTAIN OBSCURATION AND SNOW
SHOWERS WILL PERSIST OUT WEST INTO THE EVENING BEFORE RETREATING TO
THE HIGHER PEAKS. LOW CLOUDS AND PATCHY FOG MAY FORM IN THE JACKSON
AND STAR VALLEYS OVERNIGHT AFFECTING THE KJAC TERMINAL WITH MVFR
CONDITIONS. ANOTHER AREA OF LOW CLOUDS AND FOG MAY FORM OVER NATRONA
COUNTY BY LATER TONIGHT AFFECTING THE KCPR TERMINAL BY SUNRISE.
OTHERWISE...EXPECT VFR CONDITIONS IN MOST AREAS WITH WINDS
DECREASING LATER TONIGHT. ON SATURDAY...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED IN THE FAR SOUTH INCLUDING KRKS.
OTHER AREAS WILL BE DRY WITH VFR CONDITIONS AND LESS WIND. STILL
BREEZY TO LOCALLY WINDY BUT NOT AS STRONG AS TODAY.

&&

.FIRE WEATHER...

A STRONG COLD FRONT WILL CONTINUE MOVING ACROSS CENTRAL WYOMING THIS
AFTERNOON WITH STRONG WEST TO SOUTHWEST WINDS OF 40 TO 50 MPH AND
ISOLATED TO WIDELY SCATTERED SHOWERS. THUNDERSTORMS...IF ANY...WILL
BE VERY ISOLATED AND MAINLY CONFINED TO THE NORTHEAST PART OF THE
DISTRICT. MOUNTAIN SNOW SHOWERS OUT WEST WILL DIMINISH AND RETREAT
TO THE HIGHER PEAKS WITH TIME TONIGHT. SATURDAY WILL NOT BE AS WINDY
BUT STILL BREEZY TO LOCALLY WINDY...ESPECIALLY THE MOUNTAIN AND
FOOTHILL AREAS. THERE WILL BE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN SWEETWATER COUNTY...ESPECIALLY SOUTH OF INTERSTATE
80 SATURDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...SKRBAC
LONG TERM...LAVOIE
AVIATION...SKRBAC
FIRE WEATHER...SKRBAC










000
FXUS63 KUNR 182031
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
231 PM MDT FRI APR 18 2014

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 209 PM MDT FRI APR 18 2014

FAST FLOW OVER THE PACIFIC WILL CONTINUE TO SUPPORT FAIRLY RAPID
EASTWARD MOVEMENT OF THE SHORT WAVE TROF OVER THE PAC NW THIS
MORNING. THIS TROF WILL MOVE TO CENTRAL MT BY 00Z THIS EVENING AND
TO NEAR LAKE WG BY 12Z SAT. SHORT WAVE RIDGE AHEAD OF THIS TROF
WAS LOCATED OVER WRN SD THIS AFTERNOON...EVIDENT IN IR AND WV
SATELLITE PICS WITH COLDER AND MORE CONTINUOUS HIGH CLOUDS TO ITS
WEST AND THIN HIGH CLOUDS STREAMING OVER THE RIDGE INTO OUR CWA.

AS TROF APPROACHES...BEST SUPPORT FOR ASCENT SHOWN BY 700MB Q
VECTOR CONVERGENCE SPLITS INTO TWO AREAS. THE STRONGER MOVES
NORTHEASTWARD AHEAD OF THE TROF ACROSS ND...WHILE A SECOND AREA
DVLPS OVER SOUTHEAST WY AND ELONGATES OVER THE LOW LEVEL BAROCLINIC
ZONE OVER CO...NORTHERN NE...AND EASTERN SD BY 12Z SAT.

LOW LEVEL RESPONSE TO THESE DEVELOPMENTS ALOFT IS MODEST
CYCLOGENESIS OVER NE WY AND WESTERN SD...ONGOING THIS AFTN.
ANALYSES OF SFC GEOSTROPHIC VORTICITY CHANGES REVEAL INCREASING
VALUES OVER THIS AREA THIS AFTN. THESE CHANGES SHOULD SUPPORT
ENHANCED LOW LEVEL CONVERGENCE AND INCREASED CHANCES FOR SHOWER
AND TSTM DEVELOPMENT...THOUGH PROBABILITIES WILL REMAIN LOW. 18Z
NAM AND RECENT RUNS OF THE HRRR MODEL GIVE SUPPORT TO THIS
DEVELOPMENT...THOUGH DETAILS OF STORM LOCATION/INTENSITY HAVE BEEN
VARYING FROM RUN TO RUN OF THE HRRR.

FCST SOUNDINGS INDICATE 500 TO 750 J/KG OF CAPE OVER WRN SD LATE
THIS AFTN INTO EARLY THIS EVG. VERY LIMITED MOISTURE WILL PRECLUDE
SEVERE DEVELOPMENT...BUT INVERTED V SOUNDINGS WITH HIGH LCLS
SUGGEST POTENTIAL FOR A FEW STRONG WIND GUSTS WITH ANY STORMS THAT
DO DEVELOP.

FOLLOWING PASSAGE OF THE COLD FRONT AND NORTH EASTWARD MOVEMENT OF
THE SFC LOW...BRISK NORTHWESTERLY WINDS WILL DEVELOP OVER THE
WHOLE CWA LATE TONIGHT INTO EARLY SAT MORNING WITH COOLER
TEMPERATURES AND DRY WEATHER ON SATURDAY AND SATURDAY NIGHT.


&&

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 209 PM MDT FRI APR 18 2014

THE UPPER LEVEL THERMAL RIDGE WILL SHIFT OFF TO THE
EAST SUNDAY AFTN AS AN UPPER TROUGH CROSSES NORTH DAKOTA AND SWINGS
A COOL FRONT ACROSS THE FORECAST AREA. WEAK INSTABILITY DEVELOPS
OVER WESTERN SOUTH DAKOTA AHEAD OF THE FRONT ON SUNDAY AFTERNOON.
HOWEVER DUE TO THE LOW RH OF THE AIRMASS IN PLACE AT THE TIME WILL
LEAVE THE SUN AFTN FORECAST DRY. THE UPPER RIDGE WILL REBOUND
QUICKLY OVER THE NORTHERN PLAINS ON MONDAY WITH WARM AND DRY WEATHER
CONTINUING THROUGH TUESDAY. A STRONG AND SLOW MOVING UPPER LEVEL
TROUGH WILL CREATE CHANCES OF PRECIPITATION FROM TUESDAY NIGHT INTO
FRIDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY TUESDAY/WEDNESDAY.
MODELS REMAIN IN DECENT AGREEMENT IN PUSHING THE MAIN UPPER
LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF CWA...WHICH
WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT SOME SLUSHY
SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND SYSTEM IN
QUESTION.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)
ISSUED AT 209 PM MDT FRI APR 18 2014

VFR CONDITIONS WILL PREVAIL OVER MOST AREAS THROUGH TONIGHT. THERE IS
A CHANCE OF TSRA THIS AFTERNOON/EVENING WITH LOCALIZED MVFR VSBYS.
GUSTY SOUTHERLY WINDS ARE EXPECTED AHEAD OF A COLD FRONT
TODAY...WITH THE COLD FRONT MOVING THROUGH EARLY THIS
EVENING...FOLLOWED BY NORTHWEST WINDS.

&&

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

$$

SHORT TERM...BARBER
LONG TERM...10
AVIATION...10






000
FXUS65 KRIW 181753
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1153 AM MDT FRI APR 18 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWS COMPLEX BUT MOSTLY TAME UPR LVLS...WITH LOW AMPLITUDE
TROF RIDGE TROF PATTERN ACROSS THE NRN CONUS...LYING OVR TOP OF SUB
TROPICAL BASED TROF RIDGE TROF. WEAK CLOSED LOW ANCHORS THE SRN
PORTION OF THE W COAST TROF. THE NRN BRANCH OF THE UPR LVLS IS
MOVING FASTER THAN THE SRN BRANCH. RIDGE CURRENTLY OVR WY WILL GIVE
WAY TO THE QUICK MOVING TROF TO THE WEST. HOWEVER...MOISTURE
ASSOCIATED WITH THE WRN TROF IS MODEST FOR THE MOST PART DUE IN PART
TO ITS QUICK MOVEMENT WITH THE BEST WV CURRENTLY LOADED TO OUR W AND
NW...ASSOCIATED W/BAROCLINIC LEAF IN THE PAC NW...STARTING TO BE
RAPPED INTO WHAT WILL BE A RAPIDLY DEVELOPING CYCLONE WELL TO OUR N
NEAR THE NRN ID/CA BORDER. ADDITIONALLY...THERE IS JET PHASING GOING
ON NOW AS A PRECURSOR TO RAPID CYCLOGENESIS. THE SFC IS CURRENTLY
REPRESENTED BY A BROAD LOW CENTERED NEAR N CNTRL MT OUT IN FRONT OF
THE WRN TROF...W/ A LEE SIDE TROF NOW EXTENDING DOWN INTO OUR ERN
FA.

TODAY...THE PROBLEM WITH THIS MULTI-PART UPR SYSTEM IS THAT INSTEAD
OF FOCUSING ALL DYNAMICS FOR THE DEVELOPMENT OF ONE LARGE DEEP
BRUTAL SYSTEM...THE LOWER LVLS ARE GOING TO BE BUSY STRETCHING AND
TRYING TO SPIN UP AT LEAST THREE LOW PRESSURE SYSTEMS OVR THE NEXT
COUPLE OF DAYS...FROM N OF THE BORDER...S INTO THE SRN PLAINS. THE
AVAILABLE MOISTURE COMING IN FROM THE WEST WILL ALSO GET DIVVIED UP
WITH THE BEST WV HEADING UP NORTH WITH THE STRONGEST DEVELOPING
CYCLONE AND THE REST MOSTLY MISSING US SOUTH ON SATURDAY AS THE
OTHER LEE CYCLONE DEVELOPS. OUR WRN MOUNTAINS WILL FOR A SHORT
PERIOD BE IN DECENT POSITION THIS MORNING THRU MID AFTERNOON FOR
OROGRAPHICALLY INDUCED PRECIP. BY THIS AFTERNOON...LOW LVLS WILL
WARM ENOUGH...WITH SFC HIGHS E OF THE DIVIDE...APPROACHING OR JUST
CRESTING THE 70 DEG MARK IN THE BASINS AND EAST...TO CREATE SOME
INSTABILITY LATE THIS AFTERNOON AND EARLY EVENING. HOWEVER...EVEN
WITH BEST UPR FORCING FROM JET THIS AFTERNOON/EVENING...MEAGER
MOISTURE WILL SEVERELY LIMIT CONVECTIVE DEVELOPMENT FOR MOST AREAS.
THE BEST CHANCE FOR ISOLATED THUNDER E OF THE DIVIDE WILL ALL BE
ABOUT THE TIMING...AND WILL TAKE A FRONT...SOME BRIEF SHALLOW
MOISTURE POOLING NEAR NEAR THE FRONT...AND PROBABLY SOME NEARBY
TERRAIN TO LEND A HELPING HAND. ATTM...THE BEST LOCATION APPEARS TO
BE IN THE BIG HORN BASIN...WITH THE FAR SOUTHERN PORTION MOST
FAVORABLE...ALONG THE OWL CREEK AND BRIDGER MOUNTAINS...NORTH TO
PERHAPS THERMOPOLIS AND/OR WORLAND. MOSTLY DRY ADIABATIC ATMOSPHERE
SOUTH AND EAST OF THE THE BIG HORN BASIN WILL ONLY BE SLIGHTLY
UNSTABLE EVEN WITH RELATIVELY HIGH LAPSE RATES...AND THE WINDOW
SHORT FOR CONVECTION TO GET THRU. DIFFICULT TO ASCERTAIN WHERE THE
NAM IS/WAS GETTING THE RELATIVELY HIGH BL MOISTURE IN A SW FLOW
REGIME FOR NATRONA COUNTY...GENERATING RATHER LARGE CAPE. IT HAS
TONED DOWN SOME IN TONIGHTS RUN...BUT STILL SHOWS IT TO SOME
DEGREE...ALBEIT UNDER FAIRLY WELL CAPPED SKIES. OVERALL...JUST
DOESN`T LOOK ALL THAT PROMISING. STILL HAVE LOW POPS FOR LATE
AFTERNOON/EVE JUST IN CASE...WITH VIRGA THE MOSTLY LIKELY MAIN EVENT
FOR MUCH OF THE AREA. 2 INCHES OF WET SNOW AT BEST IN ISOLATED
LOCATIONS IN THE WRN MOUNTAINS...WITH MOST LOCATIONS GETTING HALF
THAT WITH SEASONALLY WARM CONDITIONS. OTHERWISE...THE SFC TO MID LVL
P AND T PATTERN WILL FAVOR INCREASED WINDS THRU THE DAY. HOWEVER IT
STILL APPEARS THAT ONLY VERY ISOLATED HIGH WIND CONDITIONS WILL
MANIFEST...IF AT ALL. JUST NOT ENOUGH CONFIDENCE TO WARN FOR THIS.

SATURDAY WILL BE SOMEWHAT COOLER N OF THE FRONT...BUT NOTHING
TOO DRASTIC WITH HIGH TEMPS STILL REACHING INTO THE MIDDLE 60S FOR
MANY LOW ELEVATION LOCALS...AND ALL WITH LESS WIND THAN FRIDAY. AS A
WEAK PRESSURE GRAD FILLS IN. STALLED FRONT NEAR AND JUST NORTH OF
THE WY/CO BORDER WILL ALLOW FOR SOME CONTINUED CONVECTIVE
DEVELOPMENT...ESPECIALLY BY MID DAY...AND MAY PUSH UP TO THE VERY
SRN REACHES OF NATRONA COUNTY. SUNDAY AFTERNOON WILL OFFER THE NEXT
BEST CHANCE FOR ISOLATED TO WIDELY SCATTERED SHOWERS WITH SOME
THUNDER AS LOW LEVELS WARM (NEAR 70S AGAIN) AND A WEAK UPR
DISTURBANCE MOVES THROUGH WHILE A WEAK CLIPPER TYPE FRONT BRUSHES
OUR ERN ZONES. GENERALLY 30 PERCENT OF LESS POPS FOR THIS
PERIOD.

.LONG TERM...MONDAY THROUGH FRIDAY

OUR MAIN WEATHER MAKER DURING THIS PERIOD WILL BE AN UPPER LOW
WOBBLING ITS WAY EASTWARD ALONG THE ALEUTIAN ISLANDS EARLY THIS
MORNING.  THIS SYSTEM WILL TAKE THE FORM OF AN UPRIGHT TROUGH ALONG
130W BY 00Z TUESDAY...PUMPING UP A RIDGE ACROSS THE ROCKIES.  THIS
WILL BRING DRY AND MILD CONDITIONS ON MONDAY.

TROUGH BECOMES MORE NEGATIVELY TILTED AS IT PUSHES INTO THE
INTERMOUNTAIN WEST ON TUESDAY AND THEN THE FUN BEGINS.  18/00Z ECMWF
IS MUCH MORE PROGRESSIVE THAN EARLIER RUNS...SWINGING THE UPPER
TROUGH ACROSS THE ROCKIES ON WEDNESDAY AND INTO THE PLAINS WEDNESDAY
NIGHT...SHORTWAVE RIDGE BUILDING IN THURSDAY MORNING.  THOUGH
GFS/GEFS MEAN HAVE ALSO TRENDED MORE PROGRESSIVE...THE DETERMINISTIC
CONTINUES BRIEFLY STALL OUT A CLOSED UPPER LOW OVER MONTANA ON
WEDNESDAY BEFORE PUSHING THE WHOLE MESSY TROUGH OUT INTO THE PLAINS
THURSDAY NIGHT.  THESE DIFFERENCES ALSO TRANSLATE INTO SUBSTANTIAL
SPREAD UPSTREAM WITH ECMWF BRINGING NEXT PACIFIC SYSTEM ONSHORE ON
FRIDAY WHILE GFS KEEPS THE SYSTEM OFF THE COAST.   ECMWF
DETERMINISTIC IS IN OVERALL AGREEMENT WITH THE EC EM...THE GFS IS ON
THE SLOW END OF ITS ENSEMBLE MEMBERS.

GIVEN THE ONGOING RUN-TO-RUN INCONSISTENCIES...THE FORECAST GIVES
THE MOST WEIGHT TO CONTINUITY.

ON TUESDAY...VERY MILD AND WINDY CONDITIONS WILL DEVELOP ACROSS
CENTRAL AREAS AS PACIFIC COLD FRONT PUSHES ACROSS IDAHO WITH
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS THE
WEST...ISOLATED STORMS SPREADING EAST LATE IN THE DAY.  SNOW LEVELS
WILL REMAIN QUITE HIGH TUESDAY AHEAD OF THE FRONT...GENERALLY AROUND
10KFT AND UP.   RAPID SNOW MELT AND SIGNIFICANT RISES IN CREEKS AND
STREAMS WILL BE A CONCERN WITH THE WARM TEMPERATURES...ESPECIALLY
WITH THE POTENTIAL FOR RAIN NEAR AND BELOW 10KFT.

ON TUESDAY NIGHT AND WEDNESDAY...COLD FRONT WILL PUSH ACROSS THE
AREA SPREADING SHOWERS AND ISOLATED THUNDERSTORMS EAST OF THE DIVIDE
WITH SNOW LEVELS LOWERING TO THE VALLEY FLOORS IN THE WEST.
PRECIPITATION LOOKS TO BE MAINLY RAIN OR A RAIN/SNOW MIX ACROSS THE
CENTRAL BASINS THROUGH THE DAY.

THURSDAY AND FRIDAY...FORECAST MAINTAINS CHANCES OF MOUNTAIN SNOW
SHOWERS WITH SLIGHT CHANCES OF RAIN/SNOW SHOWERS IN THE VALLEYS AND
BASINS DURING THIS PERIOD WITH UNCERTAINTY ON HOW FAST THIS TROUGH
WILL EXIT AND THE NEXT ONE ARRIVES.

&&

.AVIATION.../18Z ISSUANCE/

A STORM SYSTEM AND ASSOCIATED COLD FRONT PASSING THROUGH THE COWBOY
STATE WILL RESULT IN SCATTERED TO LOCALLY NUMEROUS MOUNTAIN
SNOW/VALLEY RAIN SHOWERS...MAINLY ALONG AND NORTHWEST OF A
KAFO...KPNA...KDUB...KCOD LINE THROUGH THIS AFTERNOON. THE MOST
NUMEROUS RAIN AND SNOW SHOWERS WILL BE IN THE WEST THROUGH EARLY
AFTERNOON WITH MORE ISOLATED COVERAGE EAST OF THE DIVIDE MAINLY
LATER THIS AFTERNOON AND EARLY EVENING WITH ONLY A SMALL CHANCE OF
A THUNDERSTORM EAST OF THE DIVIDE. MOUNTAIN OBSCURATIONS WILL BE
PREVALENT WEST OF THE DIVIDE WITH THESE MOUNTAIN SNOW SHOWERS WITH
SOME VALLEY MVFR AFFECTING KJAC THROUGH ABOUT 20Z. IT WILL BE
WINDY IN MANY AREAS WITH POSSIBLE LLWS AT KLND AND KCOD.
CONDITIONS WILL IMPROVE TONIGHT WITH JUST A FEW LINGERING MOUNTAIN
SNOW SHOWERS. ANOTHER SYSTEM WILL AID IN AFTERNOON SHOWERS AND
ISOLATED THUNDERSTORMS IN THE FAR SOUTH POSSIBLY AFFECTING KRKS
SATURDAY AFTERNOON.

&&

.FIRE WEATHER...

TODAY...THE BASIN ZONES WILL CLIMB NEAR OR INTO THE LOWER 70S...AHEAD OF
THE NEXT SPRING WEATHER SYSTEM DUE TO PUSH THROUGH THE FORECAST AREA
THROUGH THE DAY. MOUNTAIN INDUCED RAIN/SNOW CHANCES WILL INCREASE
THROUGH THE MORNING AND AFTERNOON HOURS... LASTING INTO THE EARLY
EVENING. HOWEVER...NEW SNOWFALL ACCUMULATIONS LOOK TO REMAIN ON THE
LOW SIDE WITH AN INCH OR TWO OF WET SNOW AT BEST. WINDS WILL ALSO
PICK UP TO THE BREEZY CATEGORY ACROSS MOST OF THE FORECAST
ZONES...WITH THE USUAL WIND PRONE AREAS OF THE SOUTHERN DISPATCH
ZONES...MOUNTAIN RIDGE TOPS AND NORTHERN CODY FOOTHILLS POSSIBLY
GETTING SOME ISOLATED HIGH WINDS. IN ADDITION...BY THIS AFTERNOON
THERE WILL BE AN INCREASING CHANCES FOR GUSTY LIGHT SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM LASTING INTO THE EVENING PERIOD.
SATURDAY...HIGH TEMPERATURES WILL BE SEASONAL...AND THE WINDS  MORE
TAME...WITH ISOLATED TO WIDELY SCATTERED CHANCES FOR SHOWERS OR AN
ISOLATED THUNDERSTORM SUNDAY AFTERNOON...MAINLY EAST OF THE
DIVIDE.

&&

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

&&

$$

UPDATE...SKRBAC
SHORT TERM...BRAUN
LONG TERM...AEM
AVIATION...WM
FIRE WEATHER...BRAUN










000
FXUS65 KCYS 181733
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1136 AM MDT FRI APR 18 2014

.UPDATE...
ISSUED AT 1016 AM MDT FRI APR 18 2014

CLOUD COVER BECOMING THICKER A BIT FASTER THAN ANTICIPATED THIS
MORNING...OTHERWISE FORECAST MOSTLY IN GOOD SHAPE. WITH THE
THICKER CLOUDS...SHAVED A FEW DEGREES OFF A FEW SITES BUT WITH
WESTERLY WINDS AND DRY AIR ALOFT...PREVIOUS FORECAST SHOULD BE
CLOSE. CAN NOT RULE OUT SOME CONVECTION THIS AFTERNOON WITH STEEP
LAPSE RATES IN PLACE...BUT GENERAL LACK OF MOISTURE AND HIGH
CLOUDS MAY INHIBIT ANY CONVECTION OUTSIDE OF THE MOUNTAINS UNTIL
THE MAIN TROUGH MOVES IN THIS EVENING.


&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 349 AM MDT FRI APR 18 2014

FORECAST CHALLENGES DEAL WITH TEMPERATURES TODAY FOLLOWED BY
SHOWER CHANCES THIS WEEKEND.

CURRENTLY...SURFACE LOW PRESSURE CURRENTLY OVER SOUTHERN IDAHO
WITH A 1017MB SURFACE HIGH OVER NORTH CENTRAL COLORADO. WINDS HAVE
STAYED UP SO FAR...WHICH IS KEEPING TEMPERATURES PRETTY WARM.
SEEING 1 AM TEMPERATURES IN THE UPPER 30S AND LOW 40S FOR MANY
LOCATIONS.

FOR TODAY...SURFACE LOW TRACKS ACROSS SOUTHERN MONTANA AND
NORTHERN WYOMING THROUGH THE DAY. GFS 700MB WINDS PICK UP TO
40KTS...SO LOOKS LIKE WE ARE IN FOR A RATHER WINDY DAY. GFS 700MB
TEMPERATURES ALSO CLIMB TO +8C. STILL THINK MOS GUIDANCE IS LOW ON
FORECAST HIGHS TODAY WITH THESE STRONG DOWNSLOPING WINDS. ADDED
3-4 DEGREES TO THE MOS GUIDANCE FOR HIGHS. LOOKING AT PROBABLY THE
WARMEST DAY THIS SEASON SO FAR WITH 80S COMMON IN THE PANHANDLE
AND 70S ACROSS SOUTHEAST WYOMING.

ONE FINAL ITEM FOR TODAY AND TONIGHT WOULD BE THUNDERSTORM CHANCES
WITH THE FRONT. NAM LIFTED INDICES OF -2 TO -3C LATE THIS
AFTERNOON AND EARLY EVENING. NAM AND GFS PAINTING SOME LIGHT QPF
OVER CONVERSE AND NIOBRARA COUNTIES AND EVEN THE NORTHERN
PANHANDLE UP NEAR CHADRON. WENT AHEAD AND UPPED POPS TO CHANCE
CATEGORY FOR EARLY THIS EVENING.

FRONT LOOKS TO MOVE THROUGH EARLY SATURDAY MORNING WITH WINDS
SHIFTING EASTERLY. GFS SHOWING SOME POOLING OF LOW LEVEL MOISTURE
OVER WESTERN NEBRASKA WITH THESE EASTERLY WINDS WITH 850MB RH
AROUND 95 PERCENT JUST EAST OF OUR CWFA. WILL NEED TO WATCH WHERE
THIS LOW LEVEL FINALLY ENDS UP PULLING...WOULD THINK IT WOULD MAKE
IT INTO THE PANHANDLE WITH THOSE TYPE OF WINDS. WILL CONTINUE TO
MONITOR.

MODELS HITTING OUR WESTERN ZONES PRETTY GOOD SATURDAY AFTERNOON
AND EVENING WITH DECENT RAINFALL. A FAIRLY POTENT SHORTWAVE TRACKS
ACROSS NORTHERN COLORADO SATURDAY AFTERNOON...THEN INTO CENTRAL
NEBRASKA SATURDAY EVENING. ALL THREE MODELS ARE IN GOOD AGREEMENT
WITH LOCATIONS. THE NAM MOST BULLISH ON QPF WITH CLOSE TO 4/10THS
QPF NEAR LARAMIE. UPPED POPS A LITTLE MORE WITH THIS GOOD
AGREEMENT IN GUIDANCE.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)

ISSUED AT 349 AM MDT FRI APR 18 2014

MODELS ARE FAIRLY SIMILAR WITH THE SYNOPTIC PATTERN THRU THE EARLY
PART OF THE WEEK...BUT THEN DIVERGE QUITE A BIT FOR WEDNESDAY AND
BEYOND. A SHORTWAVE RIDGE WILL MOVE OVERHEAD MONDAY AND MONDAY NIGHT
WITH SFC HIGH PRESSURE MOVING EAST ACROSS THE REGION. TEMPS WILL BE
SLIGHTLY COOLER WITH THE THERMAL RIDGE AND THUS WARMEST TEMPS
LAGGING JUST WEST OF THE MAIN RIDGE AXIS...WITH SOUTHEASTERLY SFC
FLOW ADVECTING LLVL MOISTURE UP ALONG THE LARAMIE RANGE. COULD SEE A
TSTORM OR TWO DEVELOP MONDAY AFTERNOON ALONG THE LARAMIE RANGE AS A
RESULT...BUT CHANCES ARE LOW. A STRONG UPPER TROUGH WILL MOVE
ONSHORE INTO CALI MONDAY NIGHT AND WILL MOVE ACROSS THE GREAT BASIN
TUESDAY. UPPER LEVEL ENERGY EJECTING OUT AHEAD OF THE TROUGH IN
SOUTHWEST FLOW WILL BRING A SLIGHT CHANCE FOR OROGRAPHIC STORMS
AGAIN TUESDAY AFTERNOON...WITH THE MORE AGGRESSIVE GFS ALSO
DEVELOPING STRONGER CONVECTION ACROSS THE NEBRASKA PLAINS TUESDAY
EVENING. WILL KEEP A SLIGHT CHANCE FOR TSTORMS IN THESE AREAS
THROUGH TUESDAY EVENING TO ACCOUNT FOR MODEL DIFFERENCES...AS THE
ECMWF IS SHOWING LESS ENERGY MOVING OVERHEAD IN ADDITION TO MARGINAL
MOISTURE. THE GFS THEN DEVELOPS A CLOSED LOW TUESDAY NIGHT WHILE THE
ECMWF KEEPS AN OPEN WAVE TROUGH. THE CANADIAN MODEL LOOKS TO BE
SOMEWHERE IN THE MIDDLE. FOR WEDNESDAY...LOOKING AT CONTINUED LOW
CHANCES FOR RAIN...WITH THE BIGGER ISSUE LOOKING TO BE WINDY
CONDITIONS DEVELOPING BEHIND THE PACIFIC FRONT THAT IS PROGGED TO
MOVE THROUGH THE CWA WEDNESDAY MORNING. THE MORE PROGRESSIVE EC
TROUGH WILL THEN MOVE INTO THE CENTRAL PLAINS AND MIDWEST WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WHILE THE GFS MAINTAINS A STRONG STORM
SYSTEM OVER THE ROCKIES AND CENTRAL PLAINS. WILL KEEP A SLIGHT
CHANCE FOR RAIN AND NIGHTTIME SNOW SHOWERS MAINLY IN THE MOUNTAINS
AND NORTHERN ZONES BUT OVERALL CONFIDENCE IS LOW DUE TO THESE
SIGNIFICANT MODEL DIFFERENCES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)
ISSUED AT 1130 AM MDT FRI APR 18 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THERE IS A SLIGHT
CHANCE FOR TSTORMS THIS EVENING MAINLY AT KCDR AS A COLD FRONT
BEGINS TO DROP SOUTH THROUGH THE REGION...BUT PROBABILITIES ARE ONLY
AROUND 15 TO 20 PERCENT. OTHERWISE...THE MAIN ISSUE WILL BE GUSTY
SOUTHWEST WINDS CONTINUING THROUGH THIS EVENING UNTIL THE FRONTAL
PASSAGE. GUSTS BETWEEN 25 TO 40 KTS ARE EXPECTED AT ALL
TERMINALS...WITH THE HIGHEST WINDS AT KRWL. THE COLD WILL STEADILY
MOVE FROM NORTH TO SOUTH ACROSS THE EASTERN PLAINS BETWEEN 05 AND
10Z TONIGHT RESULTING IN WINDS SHIFTING INTO THE NORTH AND NORTHEAST.

&&

.FIRE WEATHER...
ISSUED AT 349 AM MDT FRI APR 18 2014

ELEVATED FIRE WEATHER CONCERNS TODAY AS A LOW PRESSURE AREA MOVES
THROUGH MONTANA. WINDS REALLY BEGIN TO PICK UP TOWARDS NOON TIME
TODAY AHEAD OF THE LOW PRESSURE SYSTEM. WITH TEMPERATURES IN THE
70S ACROSS SOUTHEAST WYOMING AND 80S IN THE PANHANDLE...AFTERNOON
HUMIDITIES WILL FALL INTO THE MID TO UPPER TEENS TODAY. FRONT
ASSOCIATED WITH THE LOW PRESSURE MOVES INTO SOUTHEAST WYOMING LATE
TONIGHT...WITH WINDS SHIFTING TO THE NORTHEAST AND TEMPERATURES
COOLING DOWN SOME. INCREASING CHANCES FOR WETTING RAINS AND
MOUNTAIN SNOW SATURDAY NIGHT INTO SUNDAY FOR AREAS ALONG AND WEST
OF THE LARAMIE RANGE AS LOW PRESSURE TRACKS ACROSS NORTHERN
COLORADO.

&&

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

$$

UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...RJM
AVIATION...TJT
FIRE WEATHER...CLAYCOMB










000
FXUS63 KUNR 181721
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1121 AM MDT FRI APR 18 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 320 AM MDT FRI APR 18 2014

CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE ACROSS SOUTHERN
AB...WITH A WARM FRONT STRETCHING SOUTHEASTWARD ACROSS EASTERN MT
INTO WESTERN SD. MAIN COLD FRONT TAILS BACK WESTWARD FROM THE LOW
ACROSS SOUTHWESTERN CANADA. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE
RIDGE MOVING EAST OVER THE ROCKIES...WITH TROF MOVING QUICKLY EAST
ACROSS THE PACIFIC NW. SCATTERED TO BROKEN MID AND HIGH CLOUDS ARE
PASSING OVER THE AREA AT THIS TIME...MOST ABUNDANT OVER NORTHERN
PORTIONS OF THE CWA. TEMPS ARE IN THE LOWER 30S TO MID 40S WITH
BREEZY SOUTHERLY WINDS OVER PORTIONS OF SOUTHWESTERN INTO CENTRAL
SD.

A WARM DAY IS ON TAP ACROSS THE REGION...AHEAD OF THE APPROACHING
COLD FRONT THAT WILL PASS LATE IN THE DAY AND THIS EVENING. PRESSURE
GRADIENT WILL TIGHTEN OVER THE DAKOTAS TODAY AHEAD OF LOW PRESSURE
THAT WILL SLOWLY MOVE EAST ALONG THE CANADIAN/MT BORDER. THE
STRONGEST WINDS WILL BE ACROSS CENTRAL SD AND EASTWARD LATE THIS
MORNING AND AFTERNOON. ACROSS SOUTH CENTRAL SD...SOUTHERLY WINDS
WILL LIKELY APPROACH LOW END ADVISORY CRITERIA AT TIMES THIS
AFTERNOON...BUT SHOULD MAINLY STAY IN THE 20 TO 30 MPH RANGE...WITH
GUSTS TO AROUND 40 MPH. WARM ADVECTION WILL CONTINUE ACROSS THE AREA
THIS MORNING AS WARM FRONT DRIFTS NORTH AND EAST INTO NORTHERN SD BY
THIS AFTERNOON. HIGHS WILL MOSTLY BE IN THE 70S ACROSS THE
AREA...WITH SOME 60S OVER THE HIGHER BLACK HILLS AND LOWER 80S
LIKELY IN SOME LOCATIONS TO THE SOUTH AND EAST OF THE BLACK HILLS.

THE COLD FRONT WILL PUSH INTO NORTHWESTERN PORTIONS OF THE CWA BY
MID AFTERNOON AND THEN TRACK SOUTHEAST ACROSS THE CWA THROUGH THE
EVENING HOURS. THE MAIN PUSH OF COLDER AIR AND ASSOCIATED WINDS
BEHIND IT WILL REMAIN TO THE NORTH OF THE CWA AS OUR AREA GETS MORE
OF A GLANCING BLOW. THOUGH WINDS COULD BE RATHER GUSTY FOR AN HOUR
OR TWO BEHIND THE FRONTAL PASSAGE ACROSS THE SD PLAINS. THE MAIN
UPPER LEVEL FORCING WITH THE FAST MOVING TROF WILL REMAIN TO THE
NORTH OF THE CWA AS WELL. HOWEVER...THERE SHOULD BE SUFFICIENT LIFT
AND INSTABILITY FOR AT LEAST ISOLATED SHOWERS AND STORMS TO DEVELOP
ALONG AND BEHIND THE FRONT LATE TODAY INTO TONIGHT. WILL KEEP THE
BEST CHANCES GENERALLY ACROSS NORTHWESTERN SD FOR VERY LATE TODAY
AND THIS EVENING. THERE LOOKS TO BE POTENTIAL FOR GUSTY WINDS AND
POSSIBLY SOME SMALL HAIL WITH ANY STORMS THAT DEVELOP INTO THE
EVENING HOURS. ACTIVITY SHOULD DISSIPATE OR MOVE EAST OF THE CWA BY
LATE TONIGHT. LOWS EARLY SATURDAY WILL GENERALLY BE IN THE MID 30S
TO MID 40S.

SATURDAY LOOKS TO BE PARTLY CLOUDY AND A BIT COOLER ACROSS THE AREA.
HIGHS WILL STILL BE ABOVE AVERAGE...60S TO AROUND 70 DEGREES.
BREEZY NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE SD PLAINS DURING
THE LATE MORNING AND AFTERNOON.


&&

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 320 AM MDT FRI APR 18 2014

AN UPPER LEVEL/THERMAL RIDGE WILL DOMINATE SUNDAY AND MONDAY
BRINGING DRY WEATHER AND ABOVE NORMAL TEMPERATURES. A STRONG UPPER
LEVEL TROUGH WILL PUSH PRECIPITATION CHANCES INTO THE AREA LATER
TUESDAY THROUGH THURSDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY
TUESDAY/WEDNESDAY. MOST GUIDANCE IS IN DECENT AGREEMENT PUSHING
MAIN UPPER LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF
CWA...WHICH WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT
SOME SLUSHY SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND
SYSTEM IN QUESTION.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 320 AM MDT FRI APR 18 2014

VFR CONDITIONS WILL PREVAIL OVER MOST AREAS THROUGH TONIGHT. THERE IS
A CHANCE OF TSRA THIS AFTERNOON/EVENING WITH LOCALIZED MVFR VSBYS.
GUSTY SOUTHERLY WINDS ARE EXPECTED AHEAD OF A COLD FRONT
TODAY...WITH THE COLD FRONT MOVING THROUGH EARLY THIS
EVENING...FOLLOWED BY NORTHWEST WINDS.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10







000
FXUS63 KUNR 181721
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1121 AM MDT FRI APR 18 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 320 AM MDT FRI APR 18 2014

CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE ACROSS SOUTHERN
AB...WITH A WARM FRONT STRETCHING SOUTHEASTWARD ACROSS EASTERN MT
INTO WESTERN SD. MAIN COLD FRONT TAILS BACK WESTWARD FROM THE LOW
ACROSS SOUTHWESTERN CANADA. UPPER LEVEL ANALYSIS SHOWS SHORTWAVE
RIDGE MOVING EAST OVER THE ROCKIES...WITH TROF MOVING QUICKLY EAST
ACROSS THE PACIFIC NW. SCATTERED TO BROKEN MID AND HIGH CLOUDS ARE
PASSING OVER THE AREA AT THIS TIME...MOST ABUNDANT OVER NORTHERN
PORTIONS OF THE CWA. TEMPS ARE IN THE LOWER 30S TO MID 40S WITH
BREEZY SOUTHERLY WINDS OVER PORTIONS OF SOUTHWESTERN INTO CENTRAL
SD.

A WARM DAY IS ON TAP ACROSS THE REGION...AHEAD OF THE APPROACHING
COLD FRONT THAT WILL PASS LATE IN THE DAY AND THIS EVENING. PRESSURE
GRADIENT WILL TIGHTEN OVER THE DAKOTAS TODAY AHEAD OF LOW PRESSURE
THAT WILL SLOWLY MOVE EAST ALONG THE CANADIAN/MT BORDER. THE
STRONGEST WINDS WILL BE ACROSS CENTRAL SD AND EASTWARD LATE THIS
MORNING AND AFTERNOON. ACROSS SOUTH CENTRAL SD...SOUTHERLY WINDS
WILL LIKELY APPROACH LOW END ADVISORY CRITERIA AT TIMES THIS
AFTERNOON...BUT SHOULD MAINLY STAY IN THE 20 TO 30 MPH RANGE...WITH
GUSTS TO AROUND 40 MPH. WARM ADVECTION WILL CONTINUE ACROSS THE AREA
THIS MORNING AS WARM FRONT DRIFTS NORTH AND EAST INTO NORTHERN SD BY
THIS AFTERNOON. HIGHS WILL MOSTLY BE IN THE 70S ACROSS THE
AREA...WITH SOME 60S OVER THE HIGHER BLACK HILLS AND LOWER 80S
LIKELY IN SOME LOCATIONS TO THE SOUTH AND EAST OF THE BLACK HILLS.

THE COLD FRONT WILL PUSH INTO NORTHWESTERN PORTIONS OF THE CWA BY
MID AFTERNOON AND THEN TRACK SOUTHEAST ACROSS THE CWA THROUGH THE
EVENING HOURS. THE MAIN PUSH OF COLDER AIR AND ASSOCIATED WINDS
BEHIND IT WILL REMAIN TO THE NORTH OF THE CWA AS OUR AREA GETS MORE
OF A GLANCING BLOW. THOUGH WINDS COULD BE RATHER GUSTY FOR AN HOUR
OR TWO BEHIND THE FRONTAL PASSAGE ACROSS THE SD PLAINS. THE MAIN
UPPER LEVEL FORCING WITH THE FAST MOVING TROF WILL REMAIN TO THE
NORTH OF THE CWA AS WELL. HOWEVER...THERE SHOULD BE SUFFICIENT LIFT
AND INSTABILITY FOR AT LEAST ISOLATED SHOWERS AND STORMS TO DEVELOP
ALONG AND BEHIND THE FRONT LATE TODAY INTO TONIGHT. WILL KEEP THE
BEST CHANCES GENERALLY ACROSS NORTHWESTERN SD FOR VERY LATE TODAY
AND THIS EVENING. THERE LOOKS TO BE POTENTIAL FOR GUSTY WINDS AND
POSSIBLY SOME SMALL HAIL WITH ANY STORMS THAT DEVELOP INTO THE
EVENING HOURS. ACTIVITY SHOULD DISSIPATE OR MOVE EAST OF THE CWA BY
LATE TONIGHT. LOWS EARLY SATURDAY WILL GENERALLY BE IN THE MID 30S
TO MID 40S.

SATURDAY LOOKS TO BE PARTLY CLOUDY AND A BIT COOLER ACROSS THE AREA.
HIGHS WILL STILL BE ABOVE AVERAGE...60S TO AROUND 70 DEGREES.
BREEZY NORTHWESTERLY WINDS WILL DEVELOP ACROSS THE SD PLAINS DURING
THE LATE MORNING AND AFTERNOON.


&&

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 320 AM MDT FRI APR 18 2014

AN UPPER LEVEL/THERMAL RIDGE WILL DOMINATE SUNDAY AND MONDAY
BRINGING DRY WEATHER AND ABOVE NORMAL TEMPERATURES. A STRONG UPPER
LEVEL TROUGH WILL PUSH PRECIPITATION CHANCES INTO THE AREA LATER
TUESDAY THROUGH THURSDAY. SHRA/TSRA WILL BE POSSIBLE...ESPECIALLY
TUESDAY/WEDNESDAY. MOST GUIDANCE IS IN DECENT AGREEMENT PUSHING
MAIN UPPER LOW/SHORTWAVE ASSOCIATED WITH UPPER TROUGH NORTH OF
CWA...WHICH WOULD RESULT IN A MOSTLY LIQUID EVENT. CAN/T RULE OUT
SOME SLUSHY SNOW THURSDAY NIGHT...BUT MOISTURE AVAILABILITY BEHIND
SYSTEM IN QUESTION.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 320 AM MDT FRI APR 18 2014

VFR CONDITIONS WILL PREVAIL OVER MOST AREAS THROUGH TONIGHT. THERE IS
A CHANCE OF TSRA THIS AFTERNOON/EVENING WITH LOCALIZED MVFR VSBYS.
GUSTY SOUTHERLY WINDS ARE EXPECTED AHEAD OF A COLD FRONT
TODAY...WITH THE COLD FRONT MOVING THROUGH EARLY THIS
EVENING...FOLLOWED BY NORTHWEST WINDS.

&&

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

$$

SHORT TERM...26
LONG TERM...HELGESON
AVIATION...10






000
FXUS65 KCYS 181636
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1036 AM MDT FRI APR 18 2014

.UPDATE...
ISSUED AT 1016 AM MDT FRI APR 18 2014

CLOUD COVER BECOMING THICKER A BIT FASTER THAN ANTICIPATED THIS
MORNING...OTHERWISE FORECAST MOSTLY IN GOOD SHAPE. WITH THE
THICKER CLOUDS...SHAVED A FEW DEGREES OFF A FEW SITES BUT WITH
WESTERLY WINDS AND DRY AIR ALOFT...PREVIOUS FORECAST SHOULD BE
CLOSE. CAN NOT RULE OUT SOME CONVECTION THIS AFTERNOON WITH STEEP
LAPSE RATES IN PLACE...BUT GENERAL LACK OF MOISTURE AND HIGH
CLOUDS MAY INHIBIT ANY CONVECTION OUTSIDE OF THE MOUNTAINS UNTIL
THE MAIN TROUGH MOVES IN THIS EVENING.


&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 349 AM MDT FRI APR 18 2014

FORECAST CHALLENGES DEAL WITH TEMPERATURES TODAY FOLLOWED BY
SHOWER CHANCES THIS WEEKEND.

CURRENTLY...SURFACE LOW PRESSURE CURRENTLY OVER SOUTHERN IDAHO
WITH A 1017MB SURFACE HIGH OVER NORTH CENTRAL COLORADO. WINDS HAVE
STAYED UP SO FAR...WHICH IS KEEPING TEMPERATURES PRETTY WARM.
SEEING 1 AM TEMPERATURES IN THE UPPER 30S AND LOW 40S FOR MANY
LOCATIONS.

FOR TODAY...SURFACE LOW TRACKS ACROSS SOUTHERN MONTANA AND
NORTHERN WYOMING THROUGH THE DAY. GFS 700MB WINDS PICK UP TO
40KTS...SO LOOKS LIKE WE ARE IN FOR A RATHER WINDY DAY. GFS 700MB
TEMPERATURES ALSO CLIMB TO +8C. STILL THINK MOS GUIDANCE IS LOW ON
FORECAST HIGHS TODAY WITH THESE STRONG DOWNSLOPING WINDS. ADDED
3-4 DEGREES TO THE MOS GUIDANCE FOR HIGHS. LOOKING AT PROBABLY THE
WARMEST DAY THIS SEASON SO FAR WITH 80S COMMON IN THE PANHANDLE
AND 70S ACROSS SOUTHEAST WYOMING.

ONE FINAL ITEM FOR TODAY AND TONIGHT WOULD BE THUNDERSTORM CHANCES
WITH THE FRONT. NAM LIFTED INDICES OF -2 TO -3C LATE THIS
AFTERNOON AND EARLY EVENING. NAM AND GFS PAINTING SOME LIGHT QPF
OVER CONVERSE AND NIOBRARA COUNTIES AND EVEN THE NORTHERN
PANHANDLE UP NEAR CHADRON. WENT AHEAD AND UPPED POPS TO CHANCE
CATEGORY FOR EARLY THIS EVENING.

FRONT LOOKS TO MOVE THROUGH EARLY SATURDAY MORNING WITH WINDS
SHIFTING EASTERLY. GFS SHOWING SOME POOLING OF LOW LEVEL MOISTURE
OVER WESTERN NEBRASKA WITH THESE EASTERLY WINDS WITH 850MB RH
AROUND 95 PERCENT JUST EAST OF OUR CWFA. WILL NEED TO WATCH WHERE
THIS LOW LEVEL FINALLY ENDS UP PULLING...WOULD THINK IT WOULD MAKE
IT INTO THE PANHANDLE WITH THOSE TYPE OF WINDS. WILL CONTINUE TO MONITOR.

MODELS HITTING OUR WESTERN ZONES PRETTY GOOD SATURDAY AFTERNOON
AND EVENING WITH DECENT RAINFALL. A FAIRLY POTENT SHORTWAVE TRACKS
ACROSS NORTHERN COLORADO SATURDAY AFTERNOON...THEN INTO CENTRAL
NEBRASKA SATURDAY EVENING. ALL THREE MODELS ARE IN GOOD AGREEMENT
WITH LOCATIONS. THE NAM MOST BULLISH ON QPF WITH CLOSE TO 4/10THS
QPF NEAR LARAMIE. UPPED POPS A LITTLE MORE WITH THIS GOOD
AGREEMENT IN GUIDANCE.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)

ISSUED AT 349 AM MDT FRI APR 18 2014

MODELS ARE FAIRLY SIMILAR WITH THE SYNOPTIC PATTERN THRU THE EARLY
PART OF THE WEEK...BUT THEN DIVERGE QUITE A BIT FOR WEDNESDAY AND
BEYOND. A SHORTWAVE RIDGE WILL MOVE OVERHEAD MONDAY AND MONDAY NIGHT
WITH SFC HIGH PRESSURE MOVING EAST ACROSS THE REGION. TEMPS WILL BE
SLIGHTLY COOLER WITH THE THERMAL RIDGE AND THUS WARMEST TEMPS
LAGGING JUST WEST OF THE MAIN RIDGE AXIS...WITH SOUTHEASTERLY SFC
FLOW ADVECTING LLVL MOISTURE UP ALONG THE LARAMIE RANGE. COULD SEE A
TSTORM OR TWO DEVELOP MONDAY AFTERNOON ALONG THE LARAMIE RANGE AS A
RESULT...BUT CHANCES ARE LOW. A STRONG UPPER TROUGH WILL MOVE
ONSHORE INTO CALI MONDAY NIGHT AND WILL MOVE ACROSS THE GREAT BASIN
TUESDAY. UPPER LEVEL ENERGY EJECTING OUT AHEAD OF THE TROUGH IN
SOUTHWEST FLOW WILL BRING A SLIGHT CHANCE FOR OROGRAPHIC STORMS
AGAIN TUESDAY AFTERNOON...WITH THE MORE AGGRESSIVE GFS ALSO
DEVELOPING STRONGER CONVECTION ACROSS THE NEBRASKA PLAINS TUESDAY
EVENING. WILL KEEP A SLIGHT CHANCE FOR TSTORMS IN THESE AREAS
THROUGH TUESDAY EVENING TO ACCOUNT FOR MODEL DIFFERENCES...AS THE
ECMWF IS SHOWING LESS ENERGY MOVING OVERHEAD IN ADDITION TO MARGINAL
MOISTURE. THE GFS THEN DEVELOPS A CLOSED LOW TUESDAY NIGHT WHILE THE
ECMWF KEEPS AN OPEN WAVE TROUGH. THE CANADIAN MODEL LOOKS TO BE
SOMEWHERE IN THE MIDDLE. FOR WEDNESDAY...LOOKING AT CONTINUED LOW
CHANCES FOR RAIN...WITH THE BIGGER ISSUE LOOKING TO BE WINDY
CONDITIONS DEVELOPING BEHIND THE PACIFIC FRONT THAT IS PROGGED TO
MOVE THROUGH THE CWA WEDNESDAY MORNING. THE MORE PROGRESSIVE EC
TROUGH WILL THEN MOVE INTO THE CENTRAL PLAINS AND MIDWEST WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WHILE THE GFS MAINTAINS A STRONG STORM
SYSTEM OVER THE ROCKIES AND CENTRAL PLAINS. WILL KEEP A SLIGHT
CHANCE FOR RAIN AND NIGHTTIME SNOW SHOWERS MAINLY IN THE MOUNTAINS
AND NORTHERN ZONES BUT OVERALL CONFIDENCE IS LOW DUE TO THESE
SIGNIFICANT MODEL DIFFERENCES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 558 AM MDT FRI APR 18 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THERE IS A SLIGHT
CHANCE FOR TSTORMS THIS EVENING MAINLY AT KCDR AS A COLD FRONT
BEGINS TO DROP SOUTH THROUGH THE REGION. OTHERWISE...THE MAIN
ISSUE WILL BE GUSTY SOUTHWEST WINDS DEVELOPING LATE THIS MORNING
AND CONTINUING THROUGH THIS EVENING UNTIL COLD FRONTAL PASSAGE.
GUSTS OF 25 TO 40 KTS ARE EXPECTED AT ALL TERMINALS...WITH THE
HIGHEST WINDS AT KRWL. THE COLD WILL STEADILY MOVE FROM NORTH TO
SOUTH ACROSS THE EASTERN PLAINS BETWEEN 05 AND 10Z TONIGHT.


&&

.FIRE WEATHER...
ISSUED AT 349 AM MDT FRI APR 18 2014

ELEVATED FIRE WEATHER CONCERNS TODAY AS A LOW PRESSURE AREA MOVES
THROUGH MONTANA. WINDS REALLY BEGIN TO PICK UP TOWARDS NOON TIME
TODAY AHEAD OF THE LOW PRESSURE SYSTEM. WITH TEMPERATURES IN THE
70S ACROSS SOUTHEAST WYOMING AND 80S IN THE PANHANDLE...AFTERNOON
HUMIDITIES WILL FALL INTO THE MID TO UPPER TEENS TODAY. FRONT
ASSOCIATED WITH THE LOW PRESSURE MOVES INTO SOUTHEAST WYOMING LATE
TONIGHT...WITH WINDS SHIFTING TO THE NORTHEAST AND TEMPERATURES
COOLING DOWN SOME. INCREASING CHANCES FOR WETTING RAINS AND
MOUNTAIN SNOW SATURDAY NIGHT INTO SUNDAY FOR AREAS ALONG AND WEST
OF THE LARAMIE RANGE AS LOW PRESSURE TRACKS ACROSS NORTHERN
COLORADO.

&&

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

$$

UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...CLAYCOMB







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