568
FXUS65 KRIW 212258
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
358 PM MST SAT FEB 21 2026
KEY MESSAGES
- TEMPERATURES REMAIN AT OR SLIGHTLY BELOW SEASONAL NORMALS
SATURDAY AHEAD OF A RETURN TO ABOVE NORMAL TEMPERATURES (10 TO
15 DEGREES ABOVE) BY MONDAY. THE WARM WEATHER CONTINUES
THROUGH THE WEEK.
- A FLOW OF PACIFIC MOISTURE REACHES WESTERN WYOMING BY TUESDAY
MORNING AND ALLOWS FOR A 30 TO 36-HOUR PERIOD OF PERSISTENT
SNOW ACROSS THE NORTHWEST MOUNTAINS. EARLY INDICATIONS POINT
TO WIDESPREAD 8 TO 14 INCH SNOWFALL TOTALS WITH THE POTENTIAL
(40-60 PERCENT) FOR 15+ INCH TOTALS IN PORTIONS OF THE TETON
RANGE AND SOUTHERN ABSAROKA MOUNTAINS.
- THE WEATHER SYSTEM RESPONSIBLE FOR THE NORTHWEST MOUNTAIN SNOW
WILL GENERATE A PROLONGED PERIOD OF VERY WINDY CONDITIONS
ALONG AND EAST OF THE CONTINENTAL DIVIDE MONDAY NIGHT THROUGH
WEDNESDAY. WIDESPREAD 35 TO 45 MPH WIND GUSTS OCCUR BY
WEDNESDAY WITH CENTRAL WYOMING SEEING THE GREATEST CHANCE
(30-50 PERCENT) FOR STRONG WIND (58+ MPH).
UPDATE
ISSUED AT 120 PM MST SAT FEB 21 2026
LOWER CLOUD COVER AND FLURRIES HAVE PERSISTED OVER THE HIGHER
PEAKS AND WEST SLOPE OF THE NORTHWEST AND NORTHERN MOUNTAINS
SATURDAY MORNING, BUT THE CLOUDS AND FLURRIES FADE BY EVENING.
THIS LEAVES ONLY PASSING MID/HIGH CLOUD COVER ACROSS THE REGION
SATURDAY NIGHT AND EARLY SUNDAY. ABUNDANT SUNSHINE IS FOUND
SUNDAY AND COLDER AIR RETREATS NORTHEAST DURING THE DAY. THIS
LEADS TO SUNDAY HIGHS AT OR A TAD ABOVE NORMAL. THE WARMING
TREND CONTINUES MONDAY AS 700MB TEMPERATURES REBOUND TO AROUND
0C, LEADING TO HIGHS 45 TO 55 FOR MOST LOWER ELEVATIONS.
THERE IS INCREASING CONFIDENCE IN WIDESPREAD ACCUMULATING SNOW
TUESDAY THROUGH AT LEAST TUESDAY NIGHT ACROSS THE MOUNTAINS OF
NORTHWEST WYOMING. THE LEADING EDGE OF AN ATMOSPHERIC RIVER WITH
IVT VALUES 300-400 KG/MS REACHES THE FAR WEST TUESDAY MORNING
AND PERSISTS INTO TUESDAY NIGHT. STRONG ISENTROPIC UPGLIDE
OCCURS DURING THIS PERIOD. THERE IS A HIGH PROBABILITY (GREATER
THAN 70 PERCENT) OF WIDESPREAD NORTHWEST MOUNTAIN SNOWFALL OF AT
LEAST 8 INCHES, WHILE THE TETONS AND SOUTHERN ABSAROKAS HAVE A
40-60 PERCENT CHANCE OF TOTALS TOPPING 15 INCHES. WINTER WEATHER
HIGHLIGHTS FOR THIS PERIOD ARE LIKELY IF THESE TRENDS HOLD.
ADDITIONAL TUESDAY THROUGH WEDNESDAY CONCERNS REMAIN REGARDING
FAR WEST VALLEY RAIN/SNOW AND POTENTIALLY STRONG WIND EAST OF
THE CONTINENTAL DIVIDE. THE PREVIOUS DISCUSSION PROVIDES A
DETAILED ACCOUNT OF THESE FORECAST CHALLENGES.
DISCUSSION
ISSUED AT 1215 AM MST SAT FEB 21 2026
THINGS ARE LARGELY QUIET ACROSS WESTERN AND CENTRAL WYOMING THIS
MORNING. WE STILL HAVE A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE
WESTERN MOUNTAINS AND POSSIBLY A STRAY SHOWER ACROSS NORTHERN
BIG HORN AND JOHNSON COUNTIES, BUT NOTHING ELSE. AND MOST OF
THESE SHOULD END BY SUNRISE. OTHERWISE, RIDGING SHOULD BRING DRY
AND QUIET WEATHER THROUGH MONDAY. THE MAIN CONCERN WILL BE
TEMPERATURES. WE DID LOWER THEM A BIT, BUT IT WILL BE WARMER
THAN YESTERDAY. THE TREAD OVER THE NEXT FEW DAYS WILL BE FOR
WARMING TEMPERATURES AND FLOW TURNING SOUTHWEST. ON THE
BALANCE, BY SUNDAY TEMPERATURES SHOULD RETURN TO NEAR NORMAL AND
ABOVE NORMAL MONDAY AS THE SNOW FROM EARLIER THIS WEEK MELTS
OFF.
WIND WILL BE INCREASING SUNDAY AND ESPECIALLY MONDAY AS THE NEXT
WEATHER SYSTEM APPROACHES FROM THE WEST. THIS WILL BEGIN IN THE
FAVORED SOUTHWEST FLOW LOCATIONS LIKE CASPER SUNDAY BUT ESPECIALLY
ON MONDAY. AS FOR PRECIPITATION, THE ABSOLUTE EARLIEST ANY SHOWERS
WOULD DEVELOP IS LATER MONDAY NIGHT BUT MORE THAN LIKELY
PRECIPITATION WOULD HOLD OFF UNTIL AFTER SUNRISE TUESDAY.
AND THIS BRINGS US TO THE DISCUSSION OF THE NEXT SIGNIFICANT WEATHER
MAKER, THE NEXT PACIFIC TROUGH AND FRONT APPROACHING FROM THE WEST.
FOR THE MOST PART, THIS SYSTEM LOOKS SIMILAR TO MOST OF THE SYSTEMS
THIS WINTER WITH ZONAL FLOW. THAT MEANS UPSLOPE WEST OF THE
DIVIDE WITH THE POTENTIAL FOR A GOOD AMOUNT OF SNOW IN THE
WESTERN MOUNTAINS. THE NBM ENSEMBLE GUIDANCE GIVES A GREATER
THAN 9 IN 10 CHANCE OF OVER 6 INCHES FOR THE WESTERN MOUNTAINS
WITH A GREATER THAN 1 IN 2 CHANCE OF OVER A FOOT IN THE HIGHER
ELEVATIONS. AS FOR LOWER ELEVATIONS, THERE IS MORE UNCERTAINTY.
THIS LOOKS LIKE A FAIRLY WARM SYSTEM, WITH 700 MILLIBAR
TEMPERATURES RISING TO AS HIGH AS MINUS 3C IN SOUTHERN WYOMING
AND MINUS 5C EVEN IN NORTHWESTERN WYOMING, PUTTING SNOW LEVELS
BETWEEN 6000 AND 7000 FEET. A PLACE LIKE THE STAR VALLEY OR EVEN
JACKSON COULD SEE SOME MIXING WITH OR CHANGING TO RAIN AT TIMES
TUESDAY OR TUESDAY NIGHT BEFORE COOLER AIR MOVES IN FOR
WEDNESDAY. ENSEMBLE GUIDANCE GIVES LESS THAN A 1 IN 4 CHANCE OF
4 INCHES OR MORE THROUGH THURSDAY MORNING AS A RESULT.
AS FOR EAST OF THE DIVIDE, THE MAIN STORY ONCE AGAIN LOOKS TO
BE WIND. WIND WILL BEGIN TO INCREASE ON TUESDAY, AND BRING
ANOTHER VERY MILD DAY WITH SOME LOCATIONS SEEING HIGH
TEMPERATURES CLOSE TO 60F. HIGH WIND WILL BEGIN TO BECOME
POSSIBLE IN SOME AREAS LIKE THE ABSAROKAS AND CODY FOOTHILLS.
THE MAIN EVENT FOR THE WIND LOOKS TO BE WEDNESDAY AT THIS TIME.
AS OF NOW, THERE LOOKS TO BE A GOOD SET UP FOR HIGH WIND. THE
FRONT AND TROUGH WILL PROVIDE SOME MIXING. A POTENT JET,
POSSIBLY OVER 130 KNOTS, WILL BE DROPPING SOUTHWARD ACROSS
WYOMING. THE MOST RECENT MODEL RUNS SHOW 700 MILLIBAR WINDS
INCREASING TO 60 TO 65 KNOTS. NUMEROUS LOCATIONS EAST OF THE
DIVIDE HAVE AT LEAST A 1 IN 2 CHANCE OF WIND GUSTS PAST 55 MPH.
SO, CHANCES ARE DECENT AT THIS TIME FOR SOME WIND HIGHLIGHTS. AS
FOR PRECIPITATION, AMOUNTS WOULD BE SMALL. THE CHANCE OF A
TENTH OF AN INCH OF QPF REMAINS SMALL, GENERALLY LESS THAN A 1
OUT OF 6 CHANCE EXCEPT IN THE MOUNTAINS. THE BEST CHANCE WOULD
BE IN THE NORTH ON WEDNESDAY, WHEN THERE COULD BE SOME
ADDITIONAL LIFT FROM THE LEFT FRONT QUADRANT OF THE JET. IN THE
LOWER ELEVATIONS, IT MAY END UP BEING RAIN AS TEMPERATURES WILL
REMAIN MILD, AT LEAST AT THE ONSET.
MOST GUIDANCE SHOWS THE PRECIPITATION ENDING WEDNESDAY NIGHT AS THE
SYSTEM MOVES AWAY TO THE SOUTH AND EAST, WITH DRY AND MILD WEATHER
RETURNING FOR THURSDAY. ANOTHER SYSTEM MAY APPROACH FOR NEXT
WEEKEND, BUT GUIDANCE IS SPLIT THIS FAR OUT SO CONFIDENCE REMAINS
LOW.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 357 PM MST SAT FEB 21 2026
VFR CONDITIONS THROUGH THE PERIOD, WITH LIGHT WINDS OVERNIGHT.
PASSING HIGH CLOUDS OCCUR OVERNIGHT, CLEARING BY SUNDAY AFTERNOON.
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.
UPDATE...CNJ
DISCUSSION...HATTINGS
AVIATION...WITTMANN
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