685
FXUS65 KRIW 240906
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
206 AM MST TUE FEB 24 2026
KEY MESSAGES
- 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 CONFIDENCE HAS RISEN (70%) THAT SNOW WILL CHANGE OVER TO
RAIN IN THE AFTERNOON AND REMAIN AS RAIN THROUGH THE OVERNIGHT
HOURS TONIGHT. RAIN WILL CHANGE BACK TO SNOW BY WEDNESDAY
AFTERNOON, AS THE STORM BEGINS TO WANE.
- VERY WINDY CONDITIONS CONTINUE ALONG AND EAST OF THE
CONTINENTAL DIVIDE TODAY, WITH THE HIGHEST WINDS TUESDAY
OCCURRING OVER SOUTH PASS/RED CANYON. WEDNESDAY WILL 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 158 AM MST TUE FEB 24 2026
LIGHT SNOW HAS ALREADY STARTED OVER NORTHWESTERN PORTIONS THIS
MORNING. SNOW WILL CONTINUE TO INCREASE THROUGH 12Z THIS MORNING,
BECOMING LIKELY AND SPREADING ACROSS THE WESTERN MOUNTAINS THROUGH
18Z. GUSTY WINDS ALSO CONTINUE FOR WIND PRONE LOCATIONS. PINEY
CREEK, NEAR THE JOHNSON/SHERIDAN COUNTY LINE, ALREADY GUSTED TO 63
MPH AROUND 1130PM. CHIEF JOSEPH HIGHWAY IS CURRENTLY (AS OF 1225AM)
BLOWING AROUND 60 MPH AND HAD A 78 MPH GUST AROUND 945PM. WIND GUSTS
OF 40 TO 50 MPH ARE ALSO OCCURRING OVER SOUTH PASS/RED CANYON AND
THE SOUTH SIDE OF CASPER. DUE TO THE COMPLEX NATURE OF THIS STORM,
WE WILL ONCE AGAIN SPLIT THE DISCUSSION BETWEEN THE SNOW AND THE
WIND.
SNOW...
THE OVERALL FORECAST REMAINS ON TRACK WILL NOT MANY CHANGES. PACIFIC
MOISTURE FROM AN ATMOSPHERIC RIVER (AR) WILL CONTINUE TO MOVE OVER
THE COWBOY STATE TODAY. PRECIPITABLE WATER (PWAT) VALUES WILL
RAPIDLY INCREASE, WITH VALUES OF 0.35" TO 0.4" BECOMING WIDESPREAD
BY 12Z THIS MORNING. THIS IS WELL ABOVE THE 90TH PERCENTILE AND
TOWARD THE CLIMATOLOGICAL MAXIMUM. THIS, COUPLED WITH STRONG
ISENTROPIC LIFT, WILL LEAD TO HEAVY SNOW. THIS AFTERNOON LOOKS TO BE
THE PERIOD OF THE HEAVIEST SNOW, WITH 2"/HR SNOWFALL RATES POSSIBLE.
SNOWFALL TOTALS OF 18 TO 24 INCHES IS STILL IN THE FORECAST 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. HOWEVER, GUIDANCE HAS SHIFTED TO SNOW CHANGING OVER TO RAIN
BY EARLY AFTERNOON FOR BOTH LOCATIONS. SNOW LEVELS WILL BE ABOVE
6000FT BY THIS TIME AND INCREASE CLOSE TO 7000FT BEFORE MIDNIGHT.
PRECIPITATION WILL CHANGE BACK TO SNOW BY MIDDAY WEDNESDAY, AS AN
INCOMING CANADIAN SYSTEM DROPS SOUTHWARD. TEMPERATURES WILL
EVENTUALLY DROP BACK TO FREEZING BY MID TO LATE AFTERNOON, AS SNOW
BEGINS TO END. AREAS OF ICE WILL LIKELY BECOME A HAZARD WEDNESDAY
NIGHT, AS STANDING AREAS OF WATER FREEZE OVERNIGHT. WINDS WILL ALSO
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...
WINDS WILL DECREASE THROUGH THE REST OF THE MORNING OVER THE WARNED
AREAS WITH THE THREAT FOR HIGH WINDS (GUSTS OF 58+ MPH) ENDING
AROUND SUNRISE. THUS, WILL LIKELY EXPIRE THE WARNINGS FOR NORTHERN
JOHNSON COUNTY AND THE CODY FOOTHILLS. WIND GUSTS OF 35 TO 45 MPH
WILL BECOME MORE WIDESPREAD BY 18Z FROM SOUTHERN LINCOLN COUNTY TO
NATRONA COUNTY AND CONTINUE THROUGH THE AFTERNOON. ADDITIONALLY,
WILL EXTEND THE WARNING FOR RED CANYON/SOUTH PASS THROUGH 00Z. THESE
WINDS WILL DECREASE SLIGHTLY AFTER SUNSET, WITH GUSTS OF 30 TO 40
MPH CONTINUING THROUGH THE OVERNIGHT HOURS TUESDAY NIGHT. THE WINDS
OVER THE ABSAROKA AND WIND RIVER MOUNTAINS WILL INCREASE TO 55 TO 60
MPH THROUGH THE EARLY MORNING HOURS WEDNESDAY.
A CANADIAN SYSTEM WILL RAPIDLY DROP SOUTHWARD ACROSS THE FORECAST
AREA THROUGH THE DAY WEDNESDAY. STRONG TO HIGH WINDS ARE STILL
EXPECTED ACROSS MUCH OF 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. WILL KEEP THE
HIGH WIND WATCHES IN PLACE 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.
THE GRADIENT WILL REMAIN TIGHT ENOUGH ACROSS THE CWA FOR WIND GUSTS
OF 30 TO 45 MPH THURSDAY AFTERNOON FROM SOUTHERN LINCOLN COUNTY TO
SOUTHERN JOHNSON COUNTY, AS WELL AS OVER THE MOUNTAINS. STRONG TO
HIGH WINDS LOOK TO RETURN TO THE CLARK AREAS AND CHIEF JOSEPH PASS
THURSDAY NIGHT, AS A TIGHT TEMPERATURE GRADIENT OF 10C AT 700MB
DEVELOPS ALONG THE EAST SLOPES OF THE ABSAROKAS. THIS WILL RESULT IN
700MB WINDS INCREASING TO 50 TO 70KT, PRODUCING A SIGNIFICANT GAP
FLOW WIND EVENT. WILL KEEP TRACK OF THIS POSSIBLE EVENT, AS WINDS
COULD GUSTS AS HIGH AS 80 MPH. OTHERWISE, CONDITIONS ARE EXPECTED TO
REMAIN DRY THURSDAY WITH ABOVE NORMAL TEMPERATURES REMAINING IN
PLACE EAST OF THE DIVIDE AND OVER SOUTHERN PORTIONS. SIMILAR
CONDITIONS RETURN FOR FRIDAY, AS MODELS CONTINUE TO KEEP THE NEXT
CANADIAN SYSTEM TO THE NORTH AND ONLY CLIPPING NORTHERN
PORTIONS/JOHNSON COUNTY.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 930 PM MST MON FEB 23 2026
WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS TERMINALS.
VFR CONDITIONS TO START THE PERIOD WITH INCOMING SHOWER ACTIVITY
FROM THE WEST. KJAC WILL SEE ACTIVITY NEAR THE TERMINAL BY 10Z
WITH HIGHER CONFIDENCE AT THE TERMINAL BY 14Z. MVFR CONDITIONS
THEREAFTER WITH IFR POSSIBLE AFTER 00Z AS A BIT COOLER AIR
PUSHES IN WEST OF THE DIVIDE. SHOWERS IN THE VICINITY OF
KPNA/KBPI AFTER 15Z WITH A MIX AFTER 17-19Z ON STATION BECOMING
LIGHT SNOW AFTER 00Z AND MVFR CONDITIONS. WINDS INCREASE AT KJAC
AFTER 14Z AND KBPI AFTER 19Z THROUGH THE 00Z TIMEFRAME WITH
THIS FIRST WAVE THAT PUSHES ACROSS THE CWA. KRKS WILL SEE GUSTS
UP TO 30KTS AFTER 19Z AND 35KTS AFTER 01Z REMAINING ELEVATED
THROUGH THE END OF THE PERIOD AND MUCH OF TUESDAY NIGHT WITH A
STRONGER FINGER OF THE LOW LEVEL JET FURTHER SOUTH. OTHERWISE,
KRKS SHOULD REMAIN DRY THIS PERIOD. EXPECT MOUNTAIN OBSCURATION
FOR ALL HIGH TERRAIN WEST OF THE DIVIDE TO INCLUDE THE ABSAROKA
AND WIND RIVER MOUNTAINS.
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL TERMINALS.
VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD AT ALL TAF SITES.
KCOD WILL SEE SHOWER ACTIVITY NEAR AFTER 17Z PUSHING OVER THE
ABSAROKAS, PUSHING ON STATION WITH THE BEST CHANCE (30-40%)
AFTER 00Z. OTHERWISE, STRONG WINDS FOR KCOD AND THE FOOTHILLS
AFTER 13Z UP TO 35KTS AND OVER 45KTS BY 17Z WITH THE WESTERLY
FUNNELING. KCPR WILL SEE GUSTS UP TO 30KTS AFTER 17Z THROUGH
SUNSET WITH ALL OTHER SITES RELATIVELY LIGHT 10KTS OR LESS. KRIW
LIKELY TO SEE DRAINAGE FLOW AFTER 01Z WITH GUSTS UP TO 18KTS
THROUGH THE END OF THE PERIOD AND INTO THE OVERNIGHT HOURS
TUESDAY. ALL OTHER SITES WILL REMAIN DRY, BUT MOUNTAIN
OBSCURATIONS WILL OCCUR FOR THE ABSAROKA AND WIND RIVER
MOUNTAINS.
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 EARLY THIS MORNING TO 5 PM MST
WEDNESDAY FOR WYZ001-002-012-014-024.
HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING FOR WYZ002.
HIGH WIND WARNING UNTIL 6 AM MST EARLY THIS MORNING FOR WYZ003-
010.
WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM
MST WEDNESDAY FOR WYZ008-009-013.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ015-016.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING
FOR WYZ015-016.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WYZ017-019-020-027>030.
DISCUSSION...LAVOIE
AVIATION...LOWE
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