511  
FXUS65 KRIW 071909  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
ISSUED BY NATIONAL WEATHER SERVICE BILLINGS MT  
109 PM MDT WED MAY 7 2025  
   
KEY MESSAGES
 
 
- RETURN TO NEAR NORMAL TEMPERATURES AND MOSTLY DRY CONDITIONS  
ACROSS THE STATE TODAY.  
 
- ISOLATED SHOWERS WILL BE POSSIBLE THURSDAY AND FRIDAY MAINLY  
ACROSS WESTERN AND NORTHERN WY.  
 
- WARM AND ABOVE NORMAL TEMPERATURES DEVELOP FOR THE END OF THE  
WEEK AND PERSIST THROUGH THE WEEKEND.  
 
- HIGH TEMPERATURES FOR THE WEEKEND MAY POSSIBLY BE 10 TO 20  
DEGREES ABOVE NORMAL WITH NEAR RECORD HIGH TEMPERATURES  
POSSIBLE.  
 

 
   
UPDATE
 
 
ISSUED AT 104 PM MDT WED MAY 7 2025  
 
SATELLITE IMAGERY SHOWS CLOUDS CONTINUING TO GRADUALLY CLEAR  
ACROSS THE STATE. SUNSHINE WILL ATTEMPT TO BREAK THROUGH ANY  
LINGERING CLOUD COVER TODAY LEADING TO A MUCH WELCOMED WARMING  
OF TEMPERATURES. AFTER HIGHS ONLY IN THE LOW TO MID 40S  
YESTERDAY TODAYS VALUES WILL RETURN TO MORE SEASONABLE RANGES.  
THE CURRENT FORECASTED HIGHS FOR TODAY RANGE IN THE LOW TO UPPER  
60S.  
 
WARM AND MAINLY DRY PATTERN CONTINUES THROUGH THE REMAINDER OF  
THE WEEK. THE ONLY EXCEPTION WILL BE MAINLY ACROSS NORTHERN AND  
WESTERN PARTS OF THE STATE WHERE CHANCES FOR ISOLATED SHOWERS  
DEVELOP DUE TO A PASSING WEAK SHORTWAVE. TEMPERATURES CONTINUE  
TO WARM THROUGH THE END OF THE WEEK WITH HIGHS CLIMBING INTO THE  
LOW TO UPPER 70S. THESE WARM TEMPERATURES LOOK TO BE THE MAIN  
CONCERN AS WE HEAD INTO A STRETCH OF MOSTLY QUIET WEATHER.  
 
ABOVE NORMAL TEMPERATURES PERSIST ACROSS THE REGION INTO THE  
WEEKEND WITH EVEN WARMER TEMPERATURES FORECAST FOR SATURDAY  
THROUGH MONDAY. CURRENT MODEL GUIDANCE IS SUGGESTING HIGHS  
POSSIBLE 10 TO 20 DEGREES ABOVE NORMAL. TEMPERATURES MAY REACH  
THE UPPER 70S WEST OF THE DIVIDE AND LOW TO MID 80S EAST OF THE  
DIVIDE. THE WARMEST TEMPERATURES MAY BE ACROSS THE BIGHORN BASIN  
WHERE HIGHS MAY NEAR 90. IF THIS WERE TO OCCUR MANY LOCATIONS  
MAY SEE NEAR RECORD BREAKING VALUES. THE OTHER CONCERN WILL BE  
THE POSSIBILITY FOR SNOW MELT IN LOCATIONS WHERE HIGH ELEVATIONS  
HAVE SEEN SNOW PACKS PRIME. THIS SITUATION WILL CONTINUE TO BE  
MONITORED AS THERE IS A POSSIBILITY FOR SOME HYDRO HAZARDS BEING  
ISSUED TO HIGHLIGHT THESE CONCERNS. AS OF WEDNESDAY THE SALT  
RIVER AND WYOMING RANGES AND ANY CONNECTING TRIBUTARIES MAY NEED  
TO BE TO MONITORED.  
 

 
   
DISCUSSION
 
 
ISSUED AT 302 AM MDT WED MAY 7 2025  
 
AFTER THE WINTRY WEATHER OF THE PAST COUPLE OF DAYS, SPRING  
WILL CONTINUE IT'S SWING OF THE PENDULUM, THIS TIME INTO SPRING  
AND POSSIBLY A BIT OF SUMMER. THINGS ARE LARGELY QUIET RIGHT  
NOW, WITH RADAR ONLY SHOWING A FEW SPRINKLES IN NATRONA COUNTY.  
WE STILL HAVE CLOUD COVER HANGING AROUND THE AREA, ALTHOUGH THIS  
WILL SLOWLY PART FOR INCREASING AMOUNTS OF SUNSHINE AS THE  
UPPER LEVEL LOW OVER THE CENTRAL PLAINS STATES MOVES AWAY. SO,  
TODAY LOOKS LIKE A SEASONABLE DRY FOR THE AREA. THERE IS JUST  
ENOUGH MOISTURE AND INSTABILITY AROUND FOR A FEW SHOWERS IN THE  
AREA, BUT MOST LOCATIONS WILL NOT SEE ONE.  
 
THINGS WILL TURN A BIT MORE ACTIVE FOR THURSDAY AND FRIDAY. A  
SHORTWAVE WILL TRACK ACROSS THE AREA ON THURSDAY AND BRING SOME  
SCATTERED SHOWERS AND THUNDERSTORMS, WITH AN EMPHASIS ON  
NORTHERN AND WESTERN PORTIONS OF THE AREA WHICH WILL HAVE BETTER  
FORCING. EVEN HERE, THE CHANCE OF ANY LOCATION SEEING ONE IS  
ONLY AROUND 1 OUT OF 3 AND MOST OF THE DAY WILL REMAIN DRY. THE  
BIG CHANGE WILL BE TEMPERATURES AS FLOW TURNS TO SOUTHWEST AND  
PUSHES TEMPERATURES TO ABOVE NORMAL LEVELS, AVERAGING ABOUT 10  
DEGREES ABOVE NORMAL WITH A DECENT CHANCE OF HIGHS IN THE 80S IN  
THE NORMALLY WARMER LOCATIONS. ANOTHER SHORTWAVE MOVES IN FOR  
FRIDAY WITH ANOTHER CHANCE OF SHOWERS AND STORMS. ON THIS DAY,  
MOST MODELS AGREE WITH THE BEST COVERAGE ACROSS EASTERN PORTIONS  
OF THE AREA WITH TAPERING CHANCES FURTHER WEST. TEMPERATURES  
SHOULD BE SIMILAR TO THURSDAY.  
 
SATURDAY LOOKS LIKE A DRY AND WARM DAY AT THIS POINT. A  
APPROACHING TROUGH FOR SUNDAY WILL BRING THE CHANCE OF SHOWERS  
AND THUNDERSTORMS, SO THE WEEKEND LOOKS LIKE A 50 - 50 TYPE.  
TEMPERATURES THIS WEEKEND WILL LIKELY BE THE HIGHEST SO FAR THIS  
CALENDAR YEAR. SOME OF THE WARMER LOCATIONS, LIKE WORLAND AND  
GREYBULL, COULD MAKE A RUN AT 90 DEGREES FOR A HIGH, ESPECIALLY  
ON SUNDAY WHEN INCREASING WIND AHEAD OF THE TROUGH MAY ENHANCE  
MIXING. IF IT HAPPENS AT GREYBULL, IT COULD TIE THE EARLIEST 90  
DEGREE HIGH IN STATION HISTORY.  
 
EARLY NEXT WEEK, A LOT DEPENDS ON WHAT HAPPENS WITH AN UPPER  
LEVEL LOW THAT WILL BE MOVING ONSHORE IN THE PACIFIC NORTHWEST.  
THERE IS A LACK OF AGREEMENT IN REGARDS TO THE PROGRESSION OF  
THIS SYSTEM. IT HAS THE POTENTIAL TO BRING A DECENT RAIN OR EVEN  
STRONG THUNDERSTORMS DEPENDING ON THE SCENARIO. MY GUT FEELING  
IS THAT IT WILL BE SLOWER, SINCE THE MODELS USUALLY HAVE A FAST  
BIAS THIS FAR OUT. HOWEVER, DETAILS ON TIMING AND PLACEMENT OF  
PRECIPITATION ARE ANYONES GUESS AT THIS POINT.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
 
 
ISSUED AT 1144 AM MDT WED MAY 7 2025  
 
MVFR CIGS LINGER AT KBPI, KCPR, KLND, AND KRIW TO START THE PERIOD,  
BUT SHOULD SCATTER OUT BY 19Z TO 20Z, WITH KCPR HOLDING ONTO THOSE  
LOW CLOUDS THE LONGEST. AFTER THE LOW CLOUDS SCATTER OUT, ALL SITES  
WILL PREVAIL VFR THROUGH THE PERIOD WITH MOSTLY CLEAR SKIES. LIGHT  
WINDS ALSO GENERALLY PREVAIL THROUGH THE PERIOD. KCOD AND KWRL WILL  
BE THE ONLY EXCEPTIONS WITH GUSTS 20KTS THROUGH THE PERIOD.  
 
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  
 
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