029
FXUS65 KRIW 221719
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1019 AM MST SUN FEB 22 2026
KEY MESSAGES
- NEAR NORMAL TEMPERATURES TODAY WITH LIGHT WINDS, FOLLOWED BY
ABOVE NORMAL TEMPERATURES (10 TO 15 DEGREES ABOVE) ON MONDAY.
ABOVE NORMAL WARMTH CONTINUES THROUGH THE WORK WEEK.
- STARTING TUESDAY MORNING, THERE WILL BE A 36-HOUR PERIOD OF
PERSISTENT SNOW ACROSS THE WESTERN WYOMING MOUNTAINS.
WIDESPREAD 8 TO 12 INCH SNOWFALL TOTALS WITH THE POTENTIAL
(40-60 PERCENT) FOR 15 PLUS INCH TOTALS IN THE HIGHER PORTIONS
OF THE TETONS AND SOUTHERN ABSAROKA MOUNTAINS.
- A PROLONGED PERIOD OF VERY WINDY CONDITIONS ALONG AND EAST OF
THE CONTINENTAL DIVIDE MONDAY NIGHT THROUGH FRIDAY. WIDESPREAD
35 TO 45 MPH WIND GUSTS OCCUR BY WEDNESDAY AFTERNOON WITH
CENTRAL WYOMING SEEING THE GREATEST CHANCE (50-70 PERCENT) FOR
STRONG WIND GUSTS IN EXCESS OF 55 MPH.
DISCUSSION
ISSUED AT 231 AM MST SUN FEB 22 2026
TODAY WILL LIKELY BE THE CALMEST DAY OF THE WEEK. TEMPERATURES WILL
BE 5 TO 10 DEGREES WARMER TODAY, REBOUNDING BACK TO NEAR NORMAL
LEVELS. CONDITIONS WILL REMAIN DRY, WITH HIGH CLOUDS THIS MORNING
GIVING WAY TO CLEAR SKIES BY THE AFTERNOON. WINDS WILL BE LIGHT FOR
MOST LOCATIONS. EXCEPTIONS WILL BE THE EAST SLOPES OF THE ABSAROKA,
WIND RIVER AND BIGHORN MOUNTAINS AND THE WIND CORRIDOR EAST OF THE
DIVIDE (MUDDY GAP/JEFFREY CITY TO CASPER). GUSTS OF 25 TO 30 MPH
WILL OCCUR IN THESE AREAS. SIMILAR CONDITIONS RETURN FOR MONDAY,
WITH TEMPERATURES 10 TO 20 DEGREES WARMER ACROSS THE AREA LEADING TO
HIGHS IN THE 45F TO 55F RANGE. GUSTY WINDS WILL IMPACT THE
PREVIOUSLY MENTIONED AREAS AGAIN, WITH HIGHER GUSTS OF 35 TO 55 MPH
OCCURRING THROUGH THE AFTERNOON. WIND GUSTS OF 25 TO 35 MPH WILL BE
MORE WIDESPREAD AS WELL, FROM SOUTHERN LINCOLN COUNTY TO SOUTHERN
JOHNSON COUNTY. THESE INCREASED WINDS WILL BE DUE TO THE PRESSURE
GRADIENT TIGHTENING IRT AN APPROACHING STORM SYSTEM THAT WILL BEGIN
TO IMPACT WESTERN PORTIONS LATER MONDAY NIGHT.
AN ATMOSPHERIC RIVER (AR) WILL DEVELOP OVER THE PACNW TONIGHT INTO
MONDAY, AS A BROAD RIDGE DEVELOPS OVER MUCH OF THE INTERMOUNTAIN
WEST MONDAY NIGHT INTO TUESDAY. THIS PATTERN WILL LEAD TO THE CORE
OF THE PFJ BEING OVER THE PACNW AND CANADIAN BORDER. AT THE SAME
TIME, PACIFIC MOISTURE FROM THIS AR WILL BEGIN TO INCREASE OVER THE
REGION, WITH THE FIRST ROUNDS OF SNOW DEVELOPING OVER THE WESTERN
MOUNTAINS LATE MONDAY NIGHT. PRECIPITABLE WATER (PWAT) VALUES WILL
RAPIDLY INCREASE BETWEEN 06Z AND 12Z TUESDAY, WITH VALUES OF 0.35"
TO 0.4" BECOMING WIDESPREAD ACROSS THE COWBOY STATE. THIS IS WELL
ABOVE THE 90TH PERCENTILE AND TOWARD THE CLIMATOLOGICAL MAXIMUM.
THIS, COUPLED WITH STRONG ISENTROPIC UPSLOPE, WILL LEAD TO HEAVY
SNOW. THERE REMAINS A HIGH PROBABILITY (GREATER THAN 70 PERCENT) OF
WIDESPREAD SNOWFALL OF AT LEAST 8 INCHES OVER THE NORTHWESTERN
MOUNTAINS (INCLUDING YELLOWSTONE), WHILE THE TETONS AND SOUTHERN
ABSAROKAS HAVE A 40-60 PERCENT CHANCE OF TOTALS OVER 15 INCHES. THE
CHANCES FOR SNOW IN THE JACKSON AND STAR VALLEYS ARE HIGHLY
VARIABLE, AS MODEL SOLUTIONS ARE WAFFLING ON SNOW LEVELS (WHICH ARE
CURRENTLY BETWEEN 6000 AND 7000FT). THIS IS LIKELY DUE TO THE
PACIFIC NATURE OF THE AIRMASS. HOWEVER, THERE IS UP TO A 50% CHANCE
FOR 2 INCHES OR MORE IN THE JACKSON VALLEY (WITH HIGHER CHANCES ON
THE NORTH END OF THE VALLEY BETWEEN MOOSE AND MORAN) AND A 10 TO 20%
CHANCE IN STAR VALLEY THROUGH THE DAY TUESDAY AND INTO TUESDAY
NIGHT.
GUSTY WINDS WILL ALSO CONTINUE OVER THE MOUNTAINS AND INCREASE LATE
MONDAY NIGHT AS WELL, AS THE GRADIENT CONTINUES TO TIGHTEN AS A
SYSTEM BEGINS TO DROP SOUTHWARD FROM CANADA. 700MB WINDS WILL
INCREASE TO 50 TO 70KT BETWEEN 09Z AND 12Z TUESDAY, WITH A STRONG
DOWNSLOPING SIGNATURE OFF THE EAST SLOPES OF THE ABSAROKA AND WIND
RIVER MOUNTAINS OCCURRING BY 12Z. THIS COULD LEAD TO HIGH WINDS
(WIND GUSTS 60+ MPH) AT PLACES LIKE CODY, DUBOIS AND LANDER.
NEEDLESS TO SAY, GUSTY WINDS WILL BE MORE WIDESPREAD WITH GUSTS OF
35 TO 50 MPH OCCURRING FROM SOUTHERN LINCOLN COUNTY TO NATRONA
COUNTY TUESDAY AFTERNOON. LOCALLY HIGHER GUSTS AROUND 60 MPH WILL
OCCUR OVER SOUTH PASS. CAUTION IS ADVISED FOR TRAVELERS HERE, AS
WELL AS OVER TOGWOTEE/TETON PASS, WITH GUSTS OF 25 TO 35 MPH
OCCURRING WITH THE SNOW.
THE AFOREMENTIONED CANADIAN SYSTEM WILL RAPIDLY DROP SOUTHWARD
ACROSS THE FORECAST AREA THROUGH THE DAY WEDNESDAY. STRONG TO HIGH
WINDS WILL BE WIDESPREAD ACROSS THE CWA AS A RESULT. THE MAIN REASON
WILL BE DUE TO A 130KT JET MAX ASSOCIATED WITH THE PFJ THAT WILL BE
IN PLACE AHEAD OF THE SYSTEM. THIS WILL TRANSLATE TO 700MB WINDS OF
45 TO 60KT, WHICH WILL MIX DOWN TO THE SURFACE. MOST AREAS CAN
EXPECT WIND GUSTS OF 40 TO 60 MPH THROUGH THE DAY ON WEDNESDAY.
THESE WINDS WILL DECREASE FOR MOST AREAS AFTER SUNSET WEDNESDAY
EVENING, BUT GUSTS OF 25 TO 40 MPH WILL CONTINUE FOR WIND PRONE
LOCATIONS. MODERATE TO HEAVY SNOW WILL ALSO CONTINUE OVER THE
WESTERN MOUNTAINS WEDNESDAY, ENDING BY THE EVENING AS WELL, AS THE
MAIN SYSTEM EXITS TO THE SOUTH.
STRONG GUSTY WINDS WILL CONTINUE ACROSS THE AREA THURSDAY IN THE
WAKE OF THE STORM, AS NORTHWEST WINDS PERSIST. ANOTHER CANADIAN
STORM SYSTEM COULD IMPACT THE AREA WITH COLD TEMPERATURES AND SNOW
BY SATURDAY. MOST OF THE IMPACTS WILL LIKELY STAY EAST OF THE DIVIDE
IF CURRENT TRENDS CONTINUE.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1018 AM MST SUN FEB 22 2026
A MOSTLY CLEAR SKY TODAY, WITH ONLY SOME PASSING HIGH CLOUDS.
OTHERWISE, WINDS ARE LIGHT, WITH SOME OCCASIONAL 20 TO 25 KNOT GUSTS
AT KCPR DURING THE AFTERNOON. WINDS BEGIN TO INCREASE TOWARDS THE
END OF THE PERIOD, AHEAD OF THE NEXT WEATHER SYSTEM. WIND SHEAR
IS POSSIBLE AT KCOD, COMING OFF THE ABSAROKA MOUNTAINS, WITH
SOUTHWEST GUSTS ALSO INCREASING AT KCPR.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON ICING AND TURBULENCE FORECASTS.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...LAVOIE
AVIATION...WITTMANN
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