568  
FXUS65 KRIW 062321  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
ISSUED BY NATIONAL WEATHER SERVICE BILLINGS MT  
521 PM MDT TUE MAY 6 2025  
   
KEY MESSAGES
 
 
- SCATTERED RAIN/SNOW SHOWERS LINGER THROUGH THE AFTERNOON AND  
EVENING MAINLY FOR LOCATIONS EAST OF THE DIVIDE.  
 
- SKIES GRADUALLY CLEAR OUT OVERNIGHT WITH MOSTLY DRY CONDITIONS  
EXPECTED INTO THE WEEKEND.  
 
- WARM ABOVE NORMAL TEMPERATURES ARE LIKELY TO RETURN TO THE  
REGION BY THE END OF THE WEEK WITH THE POSSIBILITY FOR NEAR  
RECORD BREAKING HIGH TEMPERATURES BY THE WEEKEND.  
 

 
   
UPDATE
 
 
ISSUED AT 144 PM MDT TUE MAY 6 2025  
 
MUCH OF THE FORECAST REMAINS UNCHANGED AS WRAP AROUND MOISTURE  
CONTINUES TO MOVE INTO PORTIONS OF THE STATE THIS MORNING LEADING TO  
PERIODIC SHOWERS. SHOWERY ACTIVITY WILL LINGER INTO THE  
AFTERNOON AND EVENING BEFORE DISSIPATING OVERNIGHT. TEMPERATURES  
ARE FORECAST TO GRADUALLY WARM THROUGHOUT THE DAY AND WILL  
LIKELY BE WARM ENOUGH FOR MANY LOCATIONS TO SEE A TRANSITION  
BACK OVER TO RAIN. OVERALL, FORECASTED HIGHS FOR TODAY WILL BE  
WELL BELOW NORMAL WITH THE COLDEST VALUES EAST OF THE DIVIDE,  
WITH TEMPERATURES IN THE UPPER 30S TO MID 40S. WEST OF THE  
DIVIDE WILL SEE WARMING TEMPERATURES IN THE LOW 50S AS CLOUD  
COVER SCATTERS LEADING TO BRIEF PERIODS OF SUNSHINE. GUSTY WINDS  
CONTINUE ACROSS SOUTHERN WY WITH GUSTS OF 35 TO 45 KNOTS AT  
TIMES THIS AFTERNOON BEFORE GRADUALLY WEAKENING BY THE LATE  
EVENING HOURS.  
 
THE REMAINDER OF THE WEEK CONTINUES TO LOOK MOSTLY QUIET WITH  
RIDGING BUILDING IN OVER THE REGION. THERE REMAINS THE POSSIBILITY  
OF SOME ISOLATED SHOWERS OVER THE NEXT FEW DAYS BUT MOST WILL REMAIN  
DRY. WARMER TEMPERATURES ARE EXPECTED TO BUILD IN WITH HIGHS LIKELY  
BECOMING WELL ABOVE NORMAL BY THE END OF THE WEEK. MODEL GUIDANCE IS  
STARTING TO HINT AT SOME LOCATIONS MAINLY EAST OF THE DIVIDE  
REACHING THE MID 80S AND POSSIBLY UPPER 80S. THERE IS STILL TIME FOR  
THINGS TO CHANGE BUT JUST HOW WARM IT GETS WILL NEED TO BE MONITORED  
AS THIS MAY LEAD TO SOME RAPID SNOWMELT IN THE MOUNTAINS.  
 

 
   
DISCUSSION
 
 
ISSUED AT 208 AM MDT TUE MAY 6 2025  
 
WHEN I WAS GROWING UP BACK IN THE TIMES WHEN DINOSAURS ROAMED THE  
EARTH (THE 70S AND 80S FOR REFERENCE), I OFTEN ENTERTAINED MYSELF  
AFTER SCHOOL BY WATCHING RE-RUNS OF OLD SITCOMS. AND ONE MY  
FAVORITES WAS THE SECRET AGENT PARODY GET SMART. AND ONE DON ADAMS'  
(THE STAR OF THE SHOW) CATCH PHRASES WAS "MISSED IT BY THAT MUCH",  
IMPLYING A CLOSE MISS.  
 
IN REGARDS TO THIS MORNING, IT WAS THE SNOW. THE COLD CAME IN A  
LITTLE FASTER AND DEEPER THAN I THOUGHT YESTERDAY MORNING. THE  
RESULT IS BIGGER SNOW ACCUMULATIONS THEN I THOUGHT. LANDER WAS  
ALREADY UP TO 2 INCHES AT MIDNIGHT, AND WE HAVE SOME ACCUMULATION AT  
THE OFFICE AS WELL. MOST ROADS BELOW AROUND 5800 FEET ARE MAINLY WET  
THOUGH, INCLUDING AT OUR OFFICE WHERE THE PARKING LOT HAS REMAINED  
JUST WET. WE DO HAVE SOME SLICK ROADS ABOVE THIS THOUGH, WITH THE  
WORST CONDITIONS OVER SOUTH PASS. SNOW WILL CONTINUE THROUGH THE  
NIGHT. HOWEVER, WE CAN SEE THE LIGHT AT THE END OF THE TUNNEL. ALL  
GUIDANCE SHOWS THE HEAVIEST PRECIPITATION ENDING AROUND SUNRISE. IN  
ADDITION, THE STRONG MAY SUN WILL HAVE AN IMPACT, MELTING THE SNOW  
OFF MOST ROADS BY MID MORNING AND THE WARMING TEMPERATURES AND LESS  
INTENSE PRECIPITATION RATES WILL SEE A LOT OF SNOW MIX WITH OR  
CHANGE BACK TO RAIN IN THE LOWER ELEVATIONS. THE CHANCES OF GREATER  
THAN AN ADDITIONAL INCH OF SNOW AFTER 6 AM ARE AT MOST 1 OUT OF 3 IN  
THE LOWER ELEVATIONS. THERE WILL STILL BE SOME DIFFICULT CONDITIONS  
OVER THE PASSES IN THE MORNING THOUGH, SO WE WILL KEEP THE  
ADVISORIES UP FOR NOW. SHOWERS WILL CONTINUE THROUGH THE DAY,  
ALTHOUGH COVERAGE WILL DECREASE, ESPECIALLY IN THE AFTERNOON WITH  
ALMOST ALL OF THEM OVER BY MIDNIGHT TONIGHT. IT WILL BE ANOTHER  
COLD DAY THOUGH, WITH MANY AREAS EAST OF THE DIVIDE STRUGGLING  
TO REACH 40 DEGREES. MOST AREAS WILL ALSO SEE THE GUSTY WIND  
DECREASE THROUGH THE DAY. THE EXCEPTION WILL BE SOUTHERN  
WYOMING, ESPECIALLY SWEETWATER COUNTY, WHERE A DECENT PRESSURE  
GRADIENT WILL REMAIN. MANY LOCATIONS, ESPECIALLY THE EASTERN  
HALF OF THE COUNTY, HAVE A GREATER THAN 1 IN 2 CHANCE OF WIND  
GUSTS PAST 40 MPH THROUGH THE DAY.  
 
THE REST OF THE FORECAST LOOKS QUIETER. A BIT OF LINGERING  
MOISTURE AND CYCLONIC CURVATURE COULD KEEP A FEW SHOWERS OVER  
THE AREA WEDNESDAY, BUT MOST AREAS WILL REMAIN DRY. OTHERWISE,  
IT WILL BE A CLOSE TO NORMAL SPRING DAY WITH TEMPERATURES NEAR  
TO SLIGHTLY BELOW NORMAL. FLOW THEN TURNS MORE WEST TO  
SOUTHWEST, AND AS A RESULT WE WILL SEE A RETURN TO ABOVE NORMAL  
TEMPERATURES ACROSS MOST OF THE AREA FROM THURSDAY THROUGH THE  
WEEKEND AS RIDGING BUILDS ACROSS THE ROCKIES. WYOMING WILL BE  
NEAR THE TOP OF THE RIDGE THOUGH, AND THIS WILL LEAD TO A COUPLE  
OF SHORTWAVES TRACKING ACROSS NORTHERN WYOMING AND BRING A  
COUPLE OF CHANCE OF SHOWERS AND THUNDERSTORMS ON THURSDAY AND  
FRIDAY. AT THIS POINT THOUGH, NO STRONG STORMS ARE EXPECTED AND  
MOST LOCATIONS SHOULD REMAIN DRY ON ANY GIVEN DAY.  
 
THE RIDGE AXIS SHOULD BE OVER THE AREA ON SATURDAY, BRINGING A  
WARM AND DRY DAY TO THE AREA. AFTER THAT, THE RIDGE MAY BREAK  
DOWN AND BRING A RETURN OF A MORE ACTIVE PATTERN. AT THIS POINT,  
SUNDAY MAY HAVE SOME THUNDERSTORMS, MAINLY IN THE WEST. THE  
MIDDLE OF NEXT WEEK LOOKS POTENTIALLY INTERESTING WITH AN UPPER  
LEVEL LOW APPROACHING THE AREA, BUT DETAILS THIS FAR OUT ARE  
IMPOSSIBLE TO PREDICT.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
 
 
ISSUED AT 505 PM MDT TUE MAY 6 2025  
 
EAST OF THE DIVIDE TERMINALS (KCOD, KCPR, KLND, KRIW, KWRL)...  
 
MOSTLY MVFR CONDITIONS AT MANY LOCATIONS TO START THE PERIOD,  
ESPECIALLY EAST OF THE DIVIDE. ANY LINGERING PRECIPITATION SHOULD BE  
CONSTRAINED TO THE HIGHER TERRAIN AND DIMINISHED INTO THE LOWER  
ELEVATIONS EAST OF THE DIVIDE. KCOD AND KWRL WILL BE THE FIRST  
LOCATIONS TO IMPROVE AND CLEAR OUT. VFR WILL BEGIN TO PREVAIL FOR  
ALL TERMINALS BY AROUND 15 TO 18Z WEDNESDAY MORNING. THERE IS A 20  
TO 30% CHANCE OF THE LOW CLOUDS LOWERING TO THE SURFACE (LIFR)  
AROUND SUNRISE FOR KRIW, KLND, AND KCPR WEDNESDAY MORNING, WITH BEST  
CHANCES AT KRIW.  
 
WEST OF THE DIVIDE TERMINALS (KBPI, KJAC, KPNA, KRKS)...  
 
VFR FOR MOST TERMINALS WITH THE EXCEPTION OF KRKS CAN BE EXPECTED  
THROUGH THE PERIOD. AT KRKS, MVFR CONDITIONS WILL LINGER THROUGH THE  
NIGHT WITH THE GUSTY WINDS DECREASING OVERNIGHT. THERE IS A 10 TO  
20% CHANCE OF FOG AROUND SUNRISE AT KBPI AND KPNA. OTHERWISE, SKIES  
WILL BECOME MOSTLY CLEAR BY THE END OF THE PERIOD WITH LIGHT  
WINDS.  
 
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...DZIEWALTOWSKI  
DISCUSSION...HATTINGS  
AVIATION...HENSLEY/LAVOIE  
 
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