749  
FXUS65 KRIW 172357  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
457 PM MST TUE DEC 17 2024  
   
KEY MESSAGES  
 
- LIGHT SNOW SHOWERS LINGER ACROSS WESTERN WYOMING MOUNTAINS,  
GRADUALLY COMING TO AN END BY WEDNESDAY AFTERNOON.  
 
- STRONG AND GUSTY WINDS FOR THE ABSAROKA MOUNTAINS, CODY  
FOOTHILLS, AND WESTERN BIGHORN BASIN WEDNESDAY AFTERNOON  
THROUGH EARLY THURSDAY MORNING.  
 
- NEAR RECORD WARMTH FOR THE END OF THE WEEK INTO THE WEEKEND  
WITH HIGHS 10 TO 20 DEGREES ABOVE NORMAL.  
 
 
   
DISCUSSION  
 
ISSUED AT 138 PM MST TUE DEC 17 2024  
 
THOSE IN STAR VALLEY AND JACKSON HOLE WOKE UP TO A WINTER WONDERLAND  
WITH A FRESH LAYER OF SNOW ON THE GROUND. SNOWFALL REPORTS THIS  
MORNING SHOW AMOUNTS RANGING FROM 5 TO 9 INCHES WITH A FEW ISOLATED  
REPORTS OF 10 OR MORE INCHES. AS FOR THOSE EAST OF THE DIVIDE, THE  
WONDERFUL DRY AND BROWN GROUND IS WHAT CONTINUES TO GREAT US EACH  
MORNING. WESTERN WY WILL SEE LIGHT SNOW SHOWERS LINGER ACROSS THE  
AREA THROUGH WEDNESDAY MORNING WITH MINIMAL ADDITIONAL ACCUMULATION  
EXPECTED. THE SYSTEM ALONG WITH ANY LINGERING SNOW SHOWERS CLEAR OUT  
BY WEDNESDAY AFTERNOON.  
 
WEDNESDAY HAS BEEN LOOKING BREEZY ACROSS PARTS OF THE STATE BUT  
RECENTLY MODELS HAVE TRENDED TOWARDS THE POSSIBILITY OF STRONG GUSTY  
WINDS. THIS IS DUE TO A SHORTWAVE MOVING ACROSS THE NORTHEASTERN  
PORTION OF THE STATE. THE JET ASSOCIATED WITH THIS SHORTWAVE IS  
LOOKING QUITE ROBUST WITH 700 MB WINDS OF 60 TO 70 KNOTS MOVING  
ACROSS NORTHERN PARTS OF THE CWA. THIS IS CREATING THE POTENTIAL FOR  
SOME STRONG DOWNSLOPING WINDS DEVELOPING ACROSS AREAS EAST OF THE  
ABSAROKAS. SPECIFICALLY ALONG THE CODY FOOTHILLS, ALONG WY-120, WY-  
296, US-212, AND OTHER LOCATIONS IN THE FAR EASTERN PORTIONS OF PARK  
COUNTY. PROBABILISTIC MODELS ARE SHOWING LOCATIONS SUCH AS CODY AND  
CLARK HAVING A 40-60% OF SEEING WIND GUSTS OF AT LEAST 55 MPH  
WEDNESDAY AFTERNOON/EVENING. OTHER LOCATIONS SUCH AS NORTHERN  
JOHNSON COUNTY, THE UPPER WIND RIVER BASIN, AND ALONG THE WIND  
CORRIDOR MAY SEE WIND GUSTS EXCEEDING 40 MPH AT TIMES WEDNESDAY  
EVENING INTO EARLY THURSDAY MORNING. AT THIS TIME HIGH WIND WATCHES  
ARE BEING ISSUED FOR THE CODY FOOTHILLS AND THE ABSAROKA MOUNTAINS  
STARTING MID DAY WEDNESDAY THROUGH LATE THURSDAY MORNING. THE MAIN  
CONCERN WILL BE STRONG WIND GUSTS OF 55 OR MORE MPH IN LOCATIONS  
SUCH AS CLARK AND CODY. THE CONCERN WITH THE ABSAROKA MOUNTAINS WILL  
BE WIND GUSTS EXCEEDING 70 MPH ESPECIALLY ALONG THE WY-296 OVER  
CHIEF JOSEPH PASS.  
 
WINDS DIMINISH GRADUALLY DURING THE DAY THURSDAY AS A RIDGE MOVES  
OVER THE REGION. TEMPERATURES ARE FORECAST TO WARM UP AS A RESULT OF  
THIS RIDGE WITH WELL ABOVE NORMAL HIGHS EXPECTED FOR THE SECOND HALF  
OF THE WEEK. MODELS ARE FORECASTING HIGHS STARTING FRIDAY TO BE IN  
THE UPPER 40S AND LOW 50S EAST OF THE DIVIDE WHICH IS NEARLY 15 TO  
20 DEGREES ABOVE NORMAL. WEST OF THE DIVIDE WILL SEE ABOVE NORMAL  
TEMPERATURES AS WELL WITH HIGHS IN THE MID TO UPPER 30S. DEPENDING  
ON HOW WARM IT GETS SOME LOCATIONS MAY NEAR RECORD VALUES WITH  
CURRENT RECORD HIGHS SITTING IN THE MID 50S FOR PLACES LIKE CASPER  
AND LANDER. LOOKING AHEAD TOWARDS THE HOLIDAY WEEK, THERE IS SOME  
SIGNS POINTING TOWARDS UNSETTLED WEATHER DEVELOPING. HOWEVER, AT  
THIS TIME UNCERTAINTY REMAINS HIGH AND IT WILL BE SOMETHING TO  
MONITOR AS WE HEAD INTO THE SECOND HALF OF THE WEEK.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/  
 
ISSUED AT 455 PM MST TUE DEC 17 2024  
 
SNOW HAS ENDED AND CONDITIONS HAVE IMPROVED FOR MOST VALLEYS  
WEST OF THE CONTINENTAL DIVIDE. SCATTERED MID-LEVEL CLOUDS  
LINGER, ESPECIALLY OVER THE MOUNTAINS WITH ISOLATED SNOW SHOWERS  
AND TERRAIN OBSCURATIONS THROUGH WEDNESDAY AFTERNOON. VFR  
CONDITIONS PREVAIL FOR BASINS AND VALLEYS OVERNIGHT INTO  
WEDNESDAY.  
 
WINDS WILL BE A MAJOR AVIATION IMPACT WEDNESDAY, ESPECIALLY  
DURING THE AFTERNOON AND EVENING. A STRONG JET STREAM OVER  
NORTHERN WYOMING IS IN AN IDEAL POSITION TO CAUSE A MOUNTAIN  
WAVE ALONG THE ABSAROKA RANGE, WITH EXTREMELY GUSTY WINDS  
IMPACTING THE WESTERN BIGHORN BASIN, INCLUDING KCOD. WIND ALOFT  
A THOUSAND OR SO FEET OFF THE GROUND WILL BE EVEN STRONGER. HAVE  
ADDED WIND SHEAR MENTION AT KCOD FOR MUCH OF THE DAY, AND MAY  
HAVE TO CONSIDER ADDING TO KLND AS WELL, ESPECIALLY FOR  
WEDNESDAY EVENING. HIGH WIND WATCHES ARE IN EFFECT FOR THE  
REGION, INDICTING THE THREAT OF 50 KT GUSTS AT THE SURFACE. KCPR  
WILL ALSO BE BREEZY DURING THE AFTERNOON, BUT WINDS IN CENTRAL  
WYOMING ARE NOT EXPECTED TO BE QUITE AS STRONG AS IN NORTHERN  
WYOMING. WINDS REMAIN ELEVATED AFTER THE TAF PERIOD, AND INTO  
OVERNIGHT HOURS ON WEDNESDAY.  
 
 
   
RIW WATCHES/WARNINGS/ADVISORIES  
 
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY  
NIGHT FOR WYZ002-003.  
 
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR  
WYZ023.  
 
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ024.  
 
 
 
 
 
DISCUSSION...DZIEWALTOWSKI  
AVIATION...VANDENBOOGART/ROWE  
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