005  
FXUS65 KRIW 282217  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
417 PM MDT TUE JUL 28 2026  
   
KEY MESSAGES  
 
- WARMER TEMPERATURES TODAY, WITH HIGHS REACHING THE MID-TO-  
UPPER 80S WEST OF THE DIVIDE AND MID-TO-UPPER 90S EAST OF THE  
DIVIDE.  
 
- LINGERING MOISTURE BRINGS ISOLATED SHOWER ACTIVITY THIS  
AFTERNOON, FOCUSED ON SOUTHERN WY.  
 
- INCREASING MOISTURE WEDNESDAY BRINGS WIDESPREAD SHOWERS AND  
THUNDERSTORMS. MONSOON MOISTURE GETS PUSHED OUT OF THE STATE FOR  
THE END OF THIS WEEK, BRINGING WARMER TEMPERATURES AND ENDING  
RAIN CHANCES.  
 
 
   
UPDATE  
 
ISSUED AT 1232 PM MDT TUE JUL 28 2026  
 
WITH LESS CLOUD COVER TODAY, WARMER TEMPERATURES WILL BE IN PLACE,  
WITH HIGHS IN THE UPPER-80S TO UPPER-90S ACROSS THE AREA. THE LATEST  
HI-RES MODELS HAVE ISOLATED SHOWERS AND STORMS MAINLY ACROSS WESTERN  
AND SOUTHWESTERN WYOMING THIS AFTERNOON. OUTFLOW GUSTS TO AROUND 40  
MPH WOULD BE THE MOST LIKELY OUTCOME FROM ANY SHOWER OR STORM. SMOKE  
FROM THE WEST IS ALSO AROUND TODAY, MAINLY ACROSS NORTHERN WYOMING,  
BUT SOME WILL BE ACROSS THE WHOLE STATE. CONDITIONS IMPROVE SOME FOR  
WEDNESDAY, WITH SMOKE THEN INCREASING OVER NORTHWESTERN WYOMING  
WEDNESDAY NIGHT.  
 
 
   
DISCUSSION  
 
ISSUED AT 241 AM MDT TUE JUL 28 2026  
 
THE ACTIVE MONSOON PATTERN OF THE PAST COUPLE WEEKS THAT HAS  
BROUGHT BENEFICIAL RAINFALL LOOKS TO BE FINALLY SHIFTING THE  
REST OF THE WEEK. THE H5 RIDGE PLACEMENT CENTERED ON THE FOUR  
CORNERS HAS BEEN EFFICIENT IN DRAWING MOISTURE NORTHWARD, AND  
WILL CONTINUE TODAY TO TRIGGER SOME SHOWER ACTIVITY FOR WY.  
TODAY, THE FOCUS OF MOISTURE LOOKS TO BE MORE ACROSS SOUTHERN  
WY, WHERE THE BEST CHANCES FOR PRECIPITATION ARE SETTING UP THIS  
AFTERNOON. SOME BRIEF DRYING IS NOTED ACROSS NORTHERN WY TODAY,  
SO SHOWER ACTIVITY WILL BE MORE LIMITED, AND FOCUSED ON HIGHER  
ELEVATIONS. THE LOWER MOISTURE FOR MOST OF THE STATE WILL BRING  
DECREASED CLOUD COVER, ALLOWING TEMPERATURES TO JUMP BACK WELL  
ABOVE NORMAL. AREAS EAST OF THE DIVIDE WILL JUMP INTO THE MID TO  
UPPER 90S, WHILE SOUTHERN WY, WITH THE BETTER SHOWER CHANCES AND  
CLOUD COVER IN THE AFTERNOON, WILL STILL REACH THE MID TO UPPER  
80S.  
 
A FINAL PUSH OF DEEPER MONSOON MOISTURE SURGES NORTHWARD  
TONIGHT, ALONG WITH ANOTHER SHORTWAVE WRAPPING AROUND THE RIDGE.  
THIS WILL BRING MUCH BETTER CHANCES FOR NUMEROUS SHOWERS AND  
THUNDERSTORMS FOR THE DAY WEDNESDAY. RAINFALL AMOUNTS WILL BE  
BENEFICIAL AGAIN, BUT STORM MOTIONS WILL BE HIGH ENOUGH TO  
PRECLUDE MOST FLOODING CONCERNS DURING THE AFTERNOON.  
 
ONCE THIS SHORTWAVE SWEEPS NORTHEAST WEDNESDAY NIGHT, THE H5  
RIDGE BULGES TO THE WEST, EFFECTIVELY SHUTTING THE DOOR ON THE  
MONSOON FLOW, AND INSTEAD DRAWING MUCH DRIER AIR FROM THE GREAT  
BASIN INTO THE STATE. THIS WILL EFFECTIVELY SHUT DOWN RAIN  
CHANCES FOR THE REST OF THE WEEK INTO THE UPCOMING WEEKEND. THE  
RIDGE ALSO BULGES BACK TO THE NORTH, BRINGING INCREASING  
TEMPERATURES ACROSS THE STATE. PROBABILITIES FOR 100 DEGREE  
TEMPERATURES THIS WEEKEND CURRENTLY SIT AT >60% EAST OF THE  
DIVIDE, AND AROUND 30% WEST OF THE DIVIDE, INCLUDING THE GREATER  
JACKSON REGION.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/  
 
ISSUED AT 400 PM MDT TUE JUL 28 2026  
 
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL TERMINALS  
THROUGH THE TAF PERIOD. A FEW SHOWERS AND THUNDERSTORMS WILL BE  
ENDING IN THE FIRST COUPLE OF HOURS OF THE TAF PERIOD. HOWEVER,  
ALL TERMINALS ARE EXPECTED TO REMAIN DRY THROUGH THE OVERNIGHT.  
ANY BREEZY WINDS WILL WEAKEN SHORTLY AFTER SUNSET WITH LIGHT  
WINDS THROUGH THE OVERNIGHT ACROSS NEARLY ALL TERMINALS. CLOUDS  
WILL INCREASE FROM THE SOUTH-SOUTHWEST BY THE PREDAWN HOURS,  
WITH CHANCES FOR SHOWERS OVER SOUTHERN/SOUTHWESTERN PORTIONS  
LATE IN THE MORNING. PROB30 GROUPS HAVE BEEN ADDED TO NEARLY  
ALL TERMINALS FROM 17Z WEDNESDAY TO THE END OF THE TAF PERIOD.  
WESTERN LOCATIONS SUCH AS KJAC, KPNA, KBPI, AND KRKS ARE  
EXPECTED TO SEE CONVECTION FIRST WITH CHANCES SPREADING TO THE  
REMAINING TERMINALS AFTER 18Z WEDNESDAY. OTHERWISE, THE MAIN  
CONCERNS WILL BE FREQUENT LIGHTNING, GUSTY OUTFLOW WINDS OF  
35KT, AND BRIEF PERIODS OF MODERATE TO HEAVY RAINFALL. MOUNTAINS  
MAY BE OBSCURED AT TIMES MAINLY DURING THE AFTERNOON/EVENING  
HOURS WEDNESDAY IN ASSOCIATION WITH DEVELOPING SHOWERS AND  
THUNDERSTORMS.  
 
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZLC AND ZDV  
FOR THE LATEST INFORMATION ON SMOKE, ICING, AND TURBULENCE  
FORECASTS.  
 
 
   
RIW WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
UPDATE...WITTMANN  
DISCUSSION...STRAUB  
AVIATION...DZIEWALTOWSKI/LAVOIE  
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