916
FXUS65 KCYS 100921
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
321 AM MDT MON MAR 10 2025
KEY MESSAGES
- STRONG, GUSTY WINDS WILL RETURN TO THE WIND PRONE AREAS
THROUGH MONDAY.
- CRITICAL FIRE WEATHER CONDITIONS EXPECTED OVER THE HIGH
PLAINS ALONG & SOUTH OF THE NORTH PLATTE RIVER VALLEY MONDAY.
- THE NEXT STORM SYSTEM WILL ARRIVE LATE THURSDAY INTO EARLY
SATURDAY, BRINGING STRONG WINDS AND A CHANCE FOR
PRECIPITATION. SNOW ACCUMULATIONS POSSIBLE FOR SOUTHEAST
WYOMING AND MOST OF WESTERN NEBRASKA.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 320 AM MDT MON MAR 10 2025
RELATIVELY MILD TEMPERATURES EARLY THIS MORNING ACROSS MUCH OF
THE AREA WITH TEMPERATURE READINGS IN THE MID 30S TO MID 40S AND
NEAR 50 IN A FEW PLACES. OF COURSE, STRONGER WINDS ACCOMPANY
THESE MILD TEMPERATURES WITH A FEW LOCATIONS ALREADY HITTING
HIGH WIND CRITERIA WITH A FEW OTHERS PRETTY CLOSE. ADDED
NORTHERN CARBON COUNTY TO THE HIGH WIND WARNING TODAY AS GUSTS
OF 59 MPH HAVE ALREADY BEEN OBSERVED AT A NEARBY RAWS SITE. THE
STRONGEST LOW TO MIDLEVEL SUBSIDENCE AND STRONGER WINDS ALOFT
ARE FORECAST TO DEVELOP OVER THE NEXT 6 TO 10 HOURS. WITH MILD
TEMPERATURES TODAY AND GOOD BOUNDARY LAYER MIXING, EXPECT WINDS
TO CONTINUE WITH A FEW GUSTS OF 60 MPH POSSIBLE OUTSIDE OF THE
CURRENT HIGH WIND WARNING AREAS. KEPT I-25 AND EASTERN PLATTE
COUNTY IN THE HIGH WIND WATCH DUE TO LOWER THAN AVERAGE
CONFIDENCE. THIS IS MAINLY DUE TO THE POSITION OF A DEVELOPING
MOUNTAIN WAVE, WHICH CAN BE CLEARLY SEEN ON IR SATELLITE
IMAGERY. I-25 NEAR COLEMAN WAS TRENDING TOWARDS WARNING CRITERIA
LATE LAST NIGHT, BUT HAVE SINCE COME DOWN, SO WILL KEEP THE
WATCH GOING FOR NOW.
OTHERWISE, PEAK WIND GUSTS SHOULD OCCUR BETWEEN 600 AM AND THE
EARLY AFTERNOON HOURS AS MIDLEVEL SUBSIDENCE AND 700MB FLOW WILL
PEAK AROUND THE TIME WHEN A WEAK COOL FRONT WILL PUSH SOUTH
INTO CENTRAL WYOMING AND STALL. GOOD BOUNDARY LAYER MIXING IS
ALSO EXPECTED WHICH COULD RESULT IN ISOLATED WIND GUSTS OF 60
MPH ELSEWHERE, INCLUDING THE I-80 SUMMIT WEST OF CHEYENNE.
CONFIDENCE IS TOO LOW AT THIS TIME TO EXPAND THE HIGH WIND
WARNING SOUTHWARD, BUT WILL CONTINUE TO MONITOR THIS MORNING.
WEAK COLD FRONT WILL SLIDE THROUGH THE AREA EARLY TUESDAY MORNING,
BUT LOWS EARLY TUESDAY SHOULD BE PRETTY CLOSE TO AVERAGE AND GENERALLY
IN THE MID 20S TO LOW 30S. INCREASED TEMPERATURES A FEW DEGREES
ALONG THE I-80 CORRIDOR WITH HIGH RES GUIDANCE TRENDING SLOWER
WITH THE MOVEMENT OF THE FRONT BEFORE IT DISSIPATES. NO PRECIPITATION
IS EXPECTED, BUT CAN'T RULE OUT SOME PATCHY FOG EARLY TUESDAY
MORNING BEHIND THE COOL FRONT. FORECAST HIGHS ON TUESDAY WILL
STILL BE ABOVE AVERAGE AND GENERALLY IN THE MID 50S TO MID 60.
NOT MANY CHANGES FOR WEDNESDAY AS ANOTHER UPPER LEVEL RIDGE AXIS
DEVELOPS ALONG THE FRONT RANGE AND ADJACENT HIGH PLAINS. EXPECT
TEMPERATURES TO REMAIN ABOVE AVERAGE WITH HIGHS IN THE 50S AND
60S. WINDS WILL ALSO NOT BE AS STRONG AS THE PREVIOUS TWO DAYS,
SO EXPECT A PLEASANT WEDNESDAY AFTERNOON.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 248 AM MDT MON MAR 10 2025
AN ACTIVE LONG TERM IS IN STORE AS MULTIPLE TROUGHS IMPACT THE AREA
AT THE END OF THIS WEEK AND THROUGH THE WEEKEND. THE FIRST TROUGH
WILL LIKELY BE THE MOST IMPACTFUL OF THE SYSTEMS PROGGED TO MOVE
INTO THE AREA. MODELS SHOW GOOD AGREEMENT ON SURFACE LOW PLACEMENT
AND TRACK, WHICH LEADS TO A BIT MORE CONFIDENCE IN THE FORECAST. AS
THE TROUGH PUSHES INTO THE ROCKIES THURSDAY NIGHT, SURFACE
CYCLOGENESIS WILL DEVELOP A LOW IN NORTHEAST COLORADO. THIS
SYSTEM APPEARS TO BE QUITE PROGRESSIVE, SO THIS LOW WILL QUICKLY
EJECT EASTWARD INTO NEBRASKA, MAKING IT INTO WESTERN IOWA BY
FRIDAY NIGHT. MOST PRECIPITATION WILL FALL DURING THE DAY
FRIDAY, BUT GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM THE
WINDOW FOR DECENT QPF IS RATHER SMALL. DETERMINISTIC MODELS AND
ENSEMBLES REFLECT THIS, SHOWING RATHER CONSERVATIVE SNOWFALL
AMOUNTS. BASED ON THE GEFS ENSEMBLE MEANS, MOST LOCATIONS LOOK
TO RECEIVE BETWEEN 1 AND 3 INCHES. THE ECMWF ENSEMBLE IS EVEN
MORE CONSERVATIVE, GENERALLY SHOWING MEANS UNDER 2 INCHES FOR
MOST CITIES. GIVEN THAT THIS STORM IS STILL ABOUT 4 TO 5 DAYS
OUT, ENSEMBLES ARE RATHER CONSISTENT, SHOWING LITTLE SPREAD
BETWEEN MEMBERS. THIS, OF COURSE, ADDS A BIT MORE CONFIDENCE TO
THE SNOWFALL AMOUNTS WITH THIS SYSTEM. BESIDES SNOW, HIGH WINDS
MAY ALSO BE A CONCERN WITH THIS STORM. AS THE SURFACE LOW
PUSHES EASTWARD, STRONG NORTHERLY WINDS WILL EXIST ON THE
BACKSIDE. THE GFS SHOWS 800 MB WINDS AT 55 KTS EAST OF THE
LARAMIE RANGE FRIDAY AFTERNOON INTO FRIDAY EVENING. GIVEN STRONG
SUBSIDENCE, THESE WINDS COULD MAKE IT DOWN TO THE SURFACE WITH
GUSTS OVER 55 MPH. THIS ALSO RAISES CONCERNS OF POTENTIAL
VISIBILITY REDUCTIONS IN BLOWING SNOW. WIND AND SNOW WILL LIKELY
BE OUT OF THE CWA BY SATURDAY MORNING.
A WEAK SHORTWAVE AT THE HEELS OF THE MAIN TROUGH WILL MOVE INTO THE
AREA SATURDAY AFTERNOON. THIS SHORTWAVE WILL BRING ANOTHER ROUND OF
LIGHT PRECIPITATION TO THE INTERSTATE 80 CORRIDOR IN SOUTHEAST
WYOMING. LUCKILY, WARMING TEMPERATURES THROUGH THE WEEKEND MAY KEEP
MOST OF THE LOWER ELEVATION PRECIPITATION AS RAIN, WHILE THE
MOUNTAINS CAN STILL EXPECT TO SEE ACCUMULATING SNOW THROUGH
SUNDAY.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1149 PM MDT SUN MAR 9 2025
MAIN AVIATION CONCERN IN THIS TAF PERIOD WILL BE STRONG WINDS
DEVELOPING MONDAY MORNING AND CONTINUING THROUGH THE DAY. AHEAD OF
THAT, SOME LLWS WILL BE POSSIBLE FOR THE REMAINDER OF TONIGHT. SOME
SCATTERED HIGH CLOUDS WILL ALSO BE POSSIBLE THROUGHOUT THE DAY FROM
POSSIBLE MOUNTAIN WAVE ACTIVITY. WINDS WILL EASE MONDAY EVENING.
FIRE WEATHER
CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED OVER PORTIONS OF THE HIGH
PLAINS WITHOUT EXISTING SNOW COVER ON MONDAY. WARM TEMPERATURES REACHING
THE 60S TO LOW 70S ON MONDAY WILL PRODUCE AFTERNOON RH BETWEEN 10 AND 15
PERCENT. ADDITIONALLY, WEST WINDS AT 15 TO 30 MPH GUSTING 35 TO 45 MPH ARE
ANTICIPATED. A FEW GUSTS AS HIGH AS 55 MPH WILL BE POSSIBLE IN LARAMIE
COUNTY. AREAS NORTH OF THE NORTH PLATTE RIVER VALLEY CAN STILL EXPECT
GUSTY WINDS AND LOW HUMIDITY, BUT THE LINGERING SNOW COVER SHOULD KEEP
CONDITIONS OUTSIDE OF CRITICAL. WARM, DRY, AND BREEZY WEATHER WILL CONTINUE
THROUGH THURSDAY PRODUCING ELEVATED FIRE WEATHER CONDITIONS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING FROM 11 AM THIS MORNING TO 7 PM MDT THIS
EVENING FOR WYZ430-431-433.
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR WYZ101.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ104.
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR WYZ106-110.
HIGH WIND WATCH THROUGH THIS AFTERNOON FOR WYZ107.
NE...RED FLAG WARNING FROM 11 AM THIS MORNING TO 7 PM MDT THIS
EVENING FOR NEZ436-437.
SHORT TERM...TJT
LONG TERM...SF
AVIATION...SF
FIRE WEATHER...MN
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