704  
FXUS65 KRIW 291732  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1032 AM MST MON DEC 29 2025  
   
KEY MESSAGES
 
 
- TEMPERATURES BACK NEAR NORMAL TODAY WITH NEARLY CLEAR SKIES.  
 
- WARMING TEMPERATURES THROUGH THE REST OF THE WEEK WITH HIGHS  
IN THE 40S.  
 
- NO PRECIP ACROSS WESTERN AND CENTRAL WY THROUGH THE REST OF  
THE WEEK, WITH ONLY LIGHT SNOW POSSIBLE FOR THE WESTERN  
MOUNTAINS THIS WEEKEND.  
 

 
   
DISCUSSION
 
 
ISSUED AT 132 AM MST MON DEC 29 2025  
 
HIGH PRESSURE WILL BE HOLDING CONTROL ALONG THE NORTHERN ROCKIES  
DURING THE NEXT SEVERAL DAYS, DEFLECTING THE STORM TRACK BACK  
INTO CANADA AND KEEPING MILD TEMPERATURES GOING FOR WYOMING.  
LOWS THIS MORNING HAVE BEEN COLD, WITH TEMPS WELL BELOW ZERO FOR  
THE WESTERN VALLEYS, AND IN THE SINGLE DIGITS ABOVE ZERO EAST OF  
THE DIVIDE. SOUTHWEST FLOW RETURNS TODAY, HELPING TO CARVE OUT  
SOME OF THE COLD POOL THAT HAS SETTLED IN THE REGION. WITH THE  
COLD POOL NOT OVERLY STRONG AND NOT REINFORCED BY ANY SNOWPACK,  
EXPECT A GOOD RECOVERY OF TEMPERATURES INTO THE 30S THIS  
AFTERNOON. WESTERN VALLEYS THAT DO HAVE SNOWPACK AND ARE  
STARTING A LOWER TEMPERATURES WILL HAVE MORE TROUBLE GETTING  
OUT OF THE TEENS THIS AFTERNOON. THIS PATTERN WILL CONTINUE  
THROUGH THE REMAINDER OF THE WEEK, AS THE RIDGE HOLDS IN PLACE,  
PUSHING SYSTEMS OFF TO THE NORTH AND CONTINUING TO CARVE UP ANY  
REMAINING COLD POOL. MOST AREAS WILL BE BACK IN THE 40S BY  
WEDNESDAY, WITH JACKSON HOLE AND STAR VALLEY HOLDING BACK A BIT  
DEPENDING ON HOW FAST SURFACE SNOW THINS OUT.  
 
THE RIDGE TRIES TO SHIFT MORE EAST LATE IN THE WEEK, OPENING THE  
DOOR FOR SOME MOISTURE TO GET BACK INTO THE WESTERN MOUNTAINS,  
BUT A LACK OF SIGNIFICANT SUPPORTING STORM SYSTEMS WILL KEEP ANY  
SNOWFALL ON THE LIGHTER SIDE FOR THE TIME BEING.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
 
 
ISSUED AT 1032 AM MST MON DEC 29 2025  
 
WITH UPPER-LEVEL HIGH PRESSURE OVER THE GREAT BASIN TODAY,  
NORTH-NORTHWEST MID- AND UPPER-LEVEL FLOW IS RESULTING IN VFR  
CONDITIONS AT ALL TAF SITES THROUGH THE DAY AND INTO TUESDAY,  
THOUGH BRIEF MVFR CONDITIONS (10-20%) ARE POSSIBLE AT KJAC TUE  
MORNING AS A WEAK MID-LEVEL DISTURBANCE MOVES FROM MT INTO  
CENTRAL AND EASTERN WY. MOST OF NORTHWEST WY IS COVERED BY A  
MID-LEVEL DECK OF CLOUDS THIS MORNING, AND THESE SHOULD  
DISSIPATE DURING THE AFTERNOON AS HIGH CLOUDS STREAM OVER THE  
STATE FROM THE NORTH. MOST TAF SITES WILL SEE RELATIVELY LIGHT  
WINDS THROUGHOUT THE TAF PERIOD, THOUGH SEVERAL, INCLUDING KBPI,  
KPNA, KRKS, & KCPR, WILL SEE GUSTY NW TO SW WINDS (20-30 KTS) DURING  
THE AFTERNOON.  
 
AS THE PREVIOUSLY MENTIONED DISTURBANCE DROPS SOUTHEAST TUESDAY  
MORNING, MID- AND HIGH-LEVEL CLOUDS WILL INCREASE ACROSS THE  
AREA FROM ABOUT 30/09Z TO 30/21Z BEFORE CLEARING LATE TUE  
AFTERNOON. GUSTY WEST-SOUTHWEST WINDS WILL RETURN TO KRKS AND  
KCPR TUE AFT AS WELL. THE NW WY MOUNTAINS ABOVE 10K FT WILL  
LIKELY BE OBSCURED THIS AFTERNOON, AND AGAIN FROM 30/09-21Z.  
 
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...STRAUB  
AVIATION...MCDONALD  
 
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