935
FXUS65 KRIW 231708
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1008 AM MST MON FEB 23 2026
KEY MESSAGES
- HIGH TEMPERATURES CLIMB TO 10 TO 15 DEGREES ABOVE NORMAL TODAY
AS WARMER AIR ARRIVES. SIMILAR DAYTIME HIGHS OCCUR THROUGH
THE WORK WEEK.
- MOUNTAIN SNOW IS FORECAST ACROSS WESTERN WYOMING TUESDAY AND
WEDNESDAY, WITH THE HEAVIEST SNOWFALL RATES BETWEEN 5 AM
TUESDAY AND 5 AM WEDNESDAY. MOUNTAINS WITHIN WINTER STORM
WARNINGS HAVE A 80 TO 90 PERCENT CHANCE OF ONE FOOT OR MORE
OF SNOW.
- WESTERN WYOMING VALLEYS WILL RECEIVE PRECIPITATION TUESDAY,
BUT WITH SURFACE AIR TEMPERATURES NEAR FREEZING, THERE IS LOW
CONFIDENCE IN SNOW LEVELS. PLACES LIKE JACKSON HOLE AND STAR
VALLEY COULD (40 PERCENT CHANCE) RECEIVE NOTABLE SNOWFALL WITH
THIS EVENT IF TEMPERATURES REMAIN SLIGHTLY COOLER THAN
CURRENTLY FORECAST.
- THERE WILL BE A PROLONGED PERIOD OF VERY WINDY CONDITIONS
ALONG AND EAST OF THE CONTINENTAL DIVIDE BEGINNING THIS
AFTERNOON AND LASTING THROUGH FRIDAY. WEDNESDAY APPEARS TO BE
THE WINDIEST DAY OF THE WEEK WITH WIDESPREAD 35 TO 45 MPH
WIND GUSTS, AND LOWER ELEVATIONS OF CENTRAL WYOMING TOPPING 50
MPH.
DISCUSSION
ISSUED AT 312 AM MST MON FEB 23 2026
HOPE YOU WERE ABLE TO ENJOY THE MOSTLY TRANQUIL CONDITIONS OVER THE
WEEKEND BECAUSE THINGS JUST GO DOWNHILL FROM HERE. THE WARMING TREND
WILL CONTINUE TODAY WITH TEMPERATURES 10 TO 20 DEGREES WARMER THAN
SUNDAY ACROSS THE AREA, LEADING TO HIGHS IN THE 45F TO 55F RANGE.
GUSTY WINDS WILL CONTINUE TO INCREASE OVER THE EAST SLOPES OF THE
ABSAROKA AND WIND RIVER MOUNTAINS, AS WELL AS THE WIND CORRIDOR EAST
OF THE DIVIDE (MUDDY GAP/JEFFREY CITY TO CASPER), WITH GUSTS OF 25
TO 35 MPH. THESE WINDS WILL INCREASE TO 35 TO 55 MPH BY EARLY
AFTERNOON, AS THE PRESSURE GRADIENT TIGHTENS IRT AN APPROACHING
STORM SYSTEM THAT WILL BEGIN TO IMPACT WESTERN PORTIONS LATER MONDAY
NIGHT. THE TIMING FOR THE HIGH WINDS OVER THE ABSAROKA MOUNTAINS AND
CODY FOOTHILLS HAS BEEN MOVED FORWARD TO THIS AFTERNOON, AS A RESULT
OF THIS APPROACHING SYSTEM. STRONG TO HIGH WINDS LOOK TO DEVELOP
OVER THE CLARK AREA AND NEAR CHIEF JOSEPH HIGHWAY BY 2PM (21Z) THIS
AFTERNOON, AND SPREADING TO AREAS WEST AND SOUTHWEST OF CODY AFTER
5PM. THE HIGH WIND WATCHES HAVE BEEN UPGRADED TO WARNINGS AND
TIMINGS HAVE SHIFTED FORWARD AS A RESULT. DUE TO THE COMPLEX NATURE
OF THE UPCOMING STORM, THE REST OF THE DISCUSSION WILL BE SPLIT
BETWEEN THE SNOW AND THE WIND.
SNOW...
AN ATMOSPHERIC RIVER (AR) HAS BEGUN TO MOVE ONSHORE OVER THE PACNW
THIS MORNING, AS A BROAD RIDGE DEVELOPS OVER MUCH OF THE
INTERMOUNTAIN WEST TODAY. 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/EARLY TUESDAY MORNING. 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 LIFT,
WILL LEAD TO HEAVY SNOW. WINTER STORM WATCHES HAVE BEEN UPGRADED TO
WARNINGS OVER THE WESTERN MOUNTAINS. ADDITIONALLY, THE WESTERN
SLOPES OF THE WIND RIVER MOUNTAINS HAS BEEN ADDED TO THE LIST OF
WARNINGS AND A WINTER WEATHER ADVISORY FOR THE JACKSON VALLEY HAS
BEEN ADDED AS WELL. SNOWFALL TOTALS OF 18 TO 24 INCHES IS EXPECTED
FOR THE MOUNTAINS, WITH LOCALLY HIGHER AMOUNTS UP TO 3 FEET POSSIBLE
IN THE TETONS. THE FORECAST CHALLENGE CONTINUES TO BE THE JACKSON
AND STAR VALLEYS. THE CHANCES FOR SNOW IN THE JACKSON AND STAR
VALLEYS REMAIN HIGHLY VARIABLE, AS MODEL SOLUTIONS CONTINUE TO
DEPICT SNOW LEVELS IN THE 6000 AND 7000FT RANGE. THIS IS LIKELY DUE
TO THE PACIFIC NATURE OF THE AIRMASS. CURRENT THINKING IS
TEMPERATURES TO RISE ABOVE FREEZING IN THE JACKSON AREA, IN THE
MIDDLE 30S, TUESDAY AFTERNOON AND DROPPING BACK BELOW FREEZING
AROUND SUNRISE WEDNESDAY MORNING. HOWEVER, IF PRECIPITATION RATES
ARE HIGH ENOUGH, THIS WOULD LEAD TO TEMPERATURES TO DROP BELOW
FREEZING AND THE RAIN CHANGING BACK OVER TO SNOW. FORECASTED LIQUID
PRECIPITATION AMOUNTS RANGE BETWEEN 0.75 AND 0.9" (WITH 0.50" OF
THAT OCCURRING DURING THE DAY TUESDAY), SO THIS COULD TURN INTO A
HEAVY SNOW EVENT FOR THE JACKSON AREA WITH TEMPERATURES HANGING JUST
ABOVE FREEZING. THIS IS TRUE FOR THE STAR VALLEY AS WELL, BUT
CONFIDENCE IS 20-30% OF THIS OCCURRING. THE NORTH END OF THE JACKSON
VALLEY (FROM MOOSE TO MORAN) IS EXPECTED TO STAY AS ALL SNOW, WITH
AMOUNTS CLOSE TO 8". WINDS WILL INCREASE WEDNESDAY MORNING, AS THE
MAIN CANADIAN STORM SYSTEM DROPS SOUTHWARD. WIND GUSTS OF 35 TO 55
MPH WILL BE WIDESPREAD AND THE SNOW WILL BECOME DRIER (NOT AS HEAVY
AND WET). THIS COULD LEAD TO VERY HAZARDOUS TRAVEL CONDITIONS OVER
TETON/TOGWOTEE PASSES, AS BLOWING SNOW WILL LEAD TO POOR VISIBILITY
CONDITIONS.
WIND...
700MB WINDS WILL INCREASE TO 50 TO 70KT AFTER 00Z TUESDAY, WITH A
STRONG DOWNSLOPING SIGNATURE OFF THE EAST SLOPES OF THE ABSAROKA AND
WIND RIVER MOUNTAINS BETWEEN 03Z AND 06Z. STRONG TO HIGH WINDS WILL
INCREASE OVER THE EAST SLOPES OF THE WIND RIVER AND BIGHORN
MOUNTAINS DURING THIS TIME. CONSIDERED ADDING THE EAST SLOPES OF THE
BIGHORNS AND NORTHERN JOHNSON COUNTY TO THE WARNINGS, BUT DO NOT
THINK THE WINDS WILL REACH CRITERIA. THE EXCEPTION WILL BE THE AREA
OF I-90 NORTH OF BUFFALO TO THE JOHNSON/SHERIDAN COUNTY LINE, WHERE
GUSTS UP TO 60 MPH COULD OCCUR BETWEEN MIDNIGHT AND 6AM TUESDAY.
WINDS WILL DECREASE THROUGH TUESDAY MORNING OVER THE WARNED AREAS
WITH THE THREAT FOR HIGH WINDS (GUSTS OF 58+ MPH) ENDING BY 18Z.
HOWEVER, GUSTS OF 35 TO 45 MPH WILL BECOME MORE WIDESPREAD FROM
SOUTHERN LINCOLN COUNTY TO NATRONA COUNTY BY THIS TIME AND CONTINUE
THROUGH THE AFTERNOON. THESE WINDS WILL DECREASE SLIGHTLY AFTER
SUNSET, WITH GUSTS OF 30 TO 40 MPH WILL CONTINUE THROUGH THE
OVERNIGHT HOURS TUESDAY NIGHT. THE WINDS OVER THE ABSAROKA AND WIND
RIVER MOUNTAINS WILL BE HIGHER, WITH GUSTS OF 55 TO 60 MPH.
A 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 140KT JET MAX ASSOCIATED WITH THE PFJ AND AN ELONGATED
VORTICITY AXIS THAT WILL SHIFT SOUTHWARD ACROSS WYOMING. 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, WITH WINDS INCREASING BY 15Z. HIGH WIND
WATCHES HAVE BEEN ISSUED FOR THE WIND RIVER BASIN, NATRONA,
SWEETWATER AND SOUTHERN LINCOLN COUNTIES. THESE WINDS WILL DECREASE
FOR MOST AREAS AFTER SUNSET WEDNESDAY EVENING, BUT GUSTS OF 25 TO 40
MPH WILL CONTINUE THROUGH THE OVERNIGHT HOURS FOR WIND PRONE
LOCATIONS.
STRONG GUSTY WINDS WILL CONTINUE ACROSS THE AREA THURSDAY IN THE
WAKE OF THE STORM, AS NORTHWEST WINDS PERSIST. TEMPERATURES WILL
REMAIN ABOVE NORMAL THURSDAY AND FRIDAY, DESPITE A NORTHWEST FLOW
PATTERN ALOFT. MODELS HAVE TRENDED AWAY FROM A CANADIAN SYSTEM
IMPACTING MUCH OF THE AREA THIS WEEKEND, INSTEAD ONLY CLIPPING
NORTHERN PORTIONS ON SATURDAY.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1006 AM MST MON FEB 23 2026
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS THROUGH THE FIRST
HALF OF THE TAF PERIOD. A WEATHER SYSTEM WILL BEGIN TO ENTER THE
REGION LATE MONDAY INTO TUESDAY MORNING. AHEAD OF THE SYSTEM WINDS
WILL BEGIN TO INCREASE AT NEARLY ALL TERMINALS. THE TERMINALS THAT
ARE LIKELY TO SEE THE STRONGEST WINDS TODAY ARE KCOD, KCPR, KJAC,
KWRL, KBPI, AND KRKS. WINDS THIS AFTERNOON AT THESE TERMINALS ARE
FORECAST TO GUST ANYWHERE FROM 20 TO 30 KNOTS. STRONGER GUSTS ARE
LIKELY AT KCOD WHERE SOME GUIDANCE IS SUGGESTING THE POSSIBILITY FOR
STRONG WIND GUSTS IN EXCESS OF 35 TO 40 KNOTS. HOWEVER, THERE IS
SOME DISCREPANCIES BETWEEN MODELS REGARDING HOW STRONG WINDS WILL
GET AT KCOD. SOME SHOW GUSTS OVER 50 KNOTS WHILE OTHERS KEEP WINDS
BELOW 30 KNOTS.
WINDS WEAKEN AT NEARLY ALL TERMINALS EXCEPT FOR KCOD AND KCPR
OVERNIGHT. THE NEARBY WEATHER SYSTEM WILL BEGIN TO BRING IN
PRECIPITATION CHANCES MAINLY THE TERMINALS WEST OF THE DIVIDE BY
THE EARLY MORNING HOURS TUESDAY. LIGHT SNOW LOOKS TO MOVE INTO
KJAC BY 10Z WITH INTENSITY INCREASING SHORTLY AFTER 12Z TUESDAY.
MVFR TO IFR CONDITIONS WILL BE POSSIBLE AT TIMES WITH IFR
CONDITIONS MORE LIKELY AFTER 12Z. TEMPERATURES WILL BE KEY AS
FORECASTED VALUES LOOK TO SIT AROUND FREEZING WHICH MAY LEAD TO
SOME MIXING OCCURRING DURING THE DAYTIME TUESDAY. KPNA AND KBPI
LOOK TO SEE PRECIPITATION MOVE IN LATER IN THE MORNING WITH
MIXING BEING MORE LIKELY DUE TO WARMER TEMPERATURES. WINDS ARE
FORECAST TO INCREASE AND PERSIST AT MOSTLY ALL TERMINALS THROUGH
THE END OF THE TAF PERIOD. MOUNTAIN OBSCURATION WILL BE A
CONCERN FOR THE SECOND HALF OF THE TAF PERIOD AS THE NEARING
SYSTEM ENTERS THE AREA.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZLC AND ZDV FOR
THE LATEST INFORMATION ON ICING AND TURBULENCE FORECASTS.
RIW WATCHES/WARNINGS/ADVISORIES
WINTER STORM WARNING FROM 5 AM TUESDAY TO 5 PM MST WEDNESDAY
FOR WYZ001-002-012-014-024.
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 11 AM MST
TUESDAY FOR WYZ002.
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 6 AM MST TUESDAY
FOR WYZ003.
WINTER WEATHER ADVISORY FROM 5 AM TUESDAY TO 5 PM MST
WEDNESDAY FOR WYZ013.
HIGH WIND WARNING FROM 11 PM THIS EVENING TO 5 PM MST TUESDAY
FOR WYZ015-016.
HIGH WIND WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
EVENING FOR WYZ015-016.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WYZ017-019-020-027>030.
DISCUSSION...LAVOIE
AVIATION...DZIEWALTOWSKI
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