401
FXUS65 KRIW 202047
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
147 PM MST THU FEB 20 2025
KEY MESSAGES
- MINOR TRAVEL IMPACTS TO I-80 WITH ADVISORY LEVEL SNOW EXPECTED
THROUGH THIS EVENING AS THE QUICK WINTER SYSTEM RACES INTO
COLORADO.
- WARMING AND DRY TREND THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK AHEAD OF THE NEXT UPPER LEVEL DISTURBANCE. TEMPERATURES
EXPECTED TO SOAR WELL INTO THE 40S AND 50S LATE WEEKEND INTO
EARLY NEXT WEEK.
UPDATE
ISSUED AT 112 PM MST THU FEB 20 2025
MIDLEVEL TROUGH CONTINUES TO SPIN THROUGH THE REGION, CURRENTLY
CENTERED ROUGHLY IN NE UT. THIS CURRENTLY HAS SOUTHERN WY IN THE
BEST WRAPAROUND SETUP FOR SNOWFALL. SNOW CURRENTLY CONTINUES
FROM KEMM TO KRKS, AND MODELS GRADUALLY DECREASE PRECIP INTO
THIS EVENING AS THE TROUGH RACES SOUTHEAST. WINTER WEATHER
ADVISORIES REMAIN IN EFFECT THROUGH LATE THIS EVENING. SKIES
WILL GRADUALLY CLEAR OVERNIGHT TONIGHT FROM NORTH TO SOUTH. THIS
WILL ALLOW NORTHERN WY TO AGAIN FALL INTO THE SINGLE DIGITS, BUT
SHOULD REMAIN ABOVE ZERO. SOUTHERN WY LIKELY WON'T CLEAR BEFORE
SUNRISE, SO LOWS TONIGHT SHOULD ONLY FALL INTO THE TEENS.
RIDGING THEN BUILDS IN BEHIND THE DEPARTING SYSTEM, WHICH WILL
START UP THE WARMING TREND ACROSS THE STATE. HIGHS TOMORROW WILL
LIKELY RETURN ABOVE FREEZING FOR MOST LOWER ELEVATIONS AS
SOUTHWEST SURFACE WINDS BEGIN TO REESTABLISH.
DISCUSSION
ISSUED AT 1245 AM MST THU FEB 20 2025
CURRENT IR DEPICTS THE NEXT QUICK MOVING SHORTWAVE ACROSS THE
NV/ID/UT TRIPOINT AS IT PUSHES EAST. WV SHOWS A WEAK FINGER OF
THE PFJ SUPPORTING IT OFF THE PACIFIC NORTHWEST COAST AS THE
MAIN PFJ EXTENDS OUT OF CANADA INTO THE GREAT PLAINS, WHERE THE
COLDEST OF THE AIR IS LOCATED. A LEESIDE LOW OUT OF IDAHO WILL
SLOWLY PUSH INTO FAR SOUTHWESTERN REACHES OF THE STATE THROUGH
THE EARLY THURSDAY MORNING HOURS WITH A WEAK SURFACE BOUNDARY
EXTENDING TO THE SOUTH OVER NORTHEASTERN UT INTO NORTHWESTERN
CO. THIS WILL KEEP MUCH OF THE MOISTURE MAINLY ALONG AND SOUTH
OF THE I-80 CORRIDOR THROUGH MUCH OF THURSDAY. HIGHEST SNOW
RATES WILL BE ACROSS THE HIGHER TERRAIN OF SOUTHERN LINCOLN
COUNTY BEFORE SUNRISE THROUGH MOST OF THE MORNING BUT MORE
LIMITED IN MINOR ACCUMULATIONS FURTHER EAST ALONG THE I-80
CORRIDOR. 60-70 PERCENT PROBABILITIES OF 2 INCHES OR MORE IN THE
LOWER ELEVATIONS FROM KEMMERER TO RKS WITH A FEW POCKETS OF
BETTER 4 INCH ACCUMULATIONS SOUTH OF RKS IN SOUTHWESTERN PARTS
OF SWEETWATER COUNTY. THIS IS WHERE THERE WILL BE THE VERY LOW
CHANCE (<10%) FOR ANY 6 INCHES OR MORE TO WARRANT THE ONGOING
ADVISORIES TO BE UPGRADED TO A WARNING. REGARDLESS, MINOR TRAVEL
IMPACTS ALONG I-80 FROM ALMOST TO WAMSUTTER AND INTO UINTA
COUNTY CAN BE EXPECTED. NORTH OF WEST WIND GUSTS UP TO 20 TO 30
MPH AFTER NOON IN THIS AREA WILL CREATE A BIT OF A CROSSWIND
THAT COULD LIMITED VISIBILITY WITH THE LINGERING SNOW IN THE
AFTERNOON. OTHERWISE, SNOW WILL TAPER OFF TOWARDS SUNSET AND
PUSH EAST AND SOUTHEAST BY MIDNIGHT.
FOR OTHER AREAS OF THE CWA, SOME PATCHY FOG ACROSS THE WIND
RIVER BASIN IS POSSIBLE (30-40%) AFTER THIS RECENT SNOW BUT WILL
ALL BE DEPENDENT ON CLOUD COVER AND IF IT CLEARS ENOUGH BY
DAYBREAK THURSDAY MORNING. THIS WILL BE MORE PREVALENT COME
FRIDAY MORNING WITH MORE CLEARING AS RIDGING BUILDS IN LATER
THURSDAY AND THROUGH THE WEEKEND AS WELL. THE MAIN TAKEAWAY FOR
WEEK'S END AND THE WEEKEND WILL BE WARMING AND DRY CONDITIONS
EXPECTED. A WIDER SPREAD OF 40S EAST OF THE DIVIDE SATURDAY WITH
30S WEST TO EVEN SOME 50S TO THE EAST SUNDAY. NBM INPUT SEEMS A
BIT HIGH AT THIS POINT BUT EVEN BLENDING IN SOME OTHER MORE
RELIABLE MODEL DATA, STILL HAS SOME OF THESE VALUES MORE LIKELY
THAN NOT EVEN THROUGH MONDAY AHEAD OF THE NEXT SYSTEM.
THE UPPER LEVEL RIDGE STARTS TO BREAK DOWN AND BROADEN COME
SUNDAY AS THE PFJ DIPS BACK A FURTHER SOUTH THROUGH MONTANA THAT
WILL OPEN UP THE NORTHWEST PACIFIC ONCE AGAIN FOR THE WESTERN
MOUNTAINS INTO EARLY NEXT WEEK. THIS WILL INCREASES SNOW
CHANCES WEST OF THE DIVIDE THROUGH MID WEEK BEFORE THE MAIN
TROUGH PUSHES EAST OVERNIGHT TUESDAY INTO WEDNESDAY. THIS WILL
BRING SOME SNOW CHANCES AND COOLER TEMPERATURES EAST OF THE
DIVIDE BUT WARMING ONCE AGAIN BY WEEK'S END. THIS FAR OUT,
LONGER TERM MODELS DO NOT SUGGEST ANYTHING SIGNIFICANT IN TERMS
OF SNOWFALL BUT MINOR ACCUMULATIONS FOR MOST AREAS WEST OF THE
DIVIDE AND SPREADING TO THE BIGHORNS WEDNESDAY. EVEN AS THE
SYSTEM PUSHES EAST, IT MIGHT EVEN JUST BE LIQUID PRECIPITATION
WITH THE ABOVE FREEZING TEMPERATURES (EVEN THOUGH COOLER) FOR
THE LOWER BASINS EAST OF THE DIVIDE. TIME WILL TELL, BUT MARCH
IS NEAR WITH THE START OF SPRING NOT THAT FAR INTO THE FUTURE.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1041 AM MST THU FEB 20 2025
A WINTER WEATHER SYSTEM CONTINUES TO IMPACTS THE REGION. GREATEST
IMPACTS CONTINUE TO BE AT KRKS, WHERE PREVAILING MVFR WITH
OCCASIONAL IFR CONDITIONS WILL PERSIST THROUGH MUCH OF THE DAY.
LATEST HI-RES MODELS INDICATE THAT THE MAIN FORCING AND SNOWFALL
IMPACTS WILL ACTUALLY STAY SOUTH OF THE TERMINAL, SO THERE IS A 20%
CHANCE THAT MOSTLY VFR COULD PREVAIL THROUGH THE REST OF THE PERIOD.
KBPI AND KPNA ALSO WILL SEE OCCASIONAL MVFR CONDITIONS WITH A 30%
CHANCE OF SNOW SHOWERS THROUGH MUCH OF THE EVENING, BUT IMPACTS LOOK
TO BE MUCH MORE SHORT-LIVED COMPARED TO KRKS.
ALL OTHER TERMINALS, INCLUDING KJAC, ARE EXPECTED TO REMAIN VFR
THROUGH THE PERIOD. KRIW AND KLND COULD SEE A BRIEF SNOW SHOWER THIS
AFTERNOON AS A COLD FRONT MOVES THROUGH, BUT CHANCES ARE GENERALLY
LESS THAN 25%.
ALL TERMINALS ARE EXPECTED TO BECOME VFR WITH SKIES CLEARING FROM
NORTH TO SOUTH FRIDAY MORNING. THERE IS A SLIGHT CHANCE (LESS THAN
20%) OF LOW CLOUDS/FOG DEVELOPING ACROSS THE BIGHORN BASIN (KWRL
TERMINAL) AND POSSIBLY IN THE WIND RIVER BASIN (KRIW TERMINAL - 10%
CHANCE) LATE IN THE PERIOD FRIDAY MORNING, BUT CONFIDENCE IS NOT
HIGH ENOUGH TO INCLUDE IN THE TAF.
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
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ027>030.
UPDATE...STRAUB
DISCUSSION...LOWE
AVIATION...HENSLEY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page