077  
FXUS65 KRIW 290418  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1018 PM MDT TUE JUL 28 2026  
   
KEY MESSAGES  
 
- WIDELY SCATTERED SHOWERS AND THUNDERSTORMS PERSIST ACROSS FAR  
WESTERN AND FAR SOUTHERN WYOMING UNTIL SHORTLY AFTER SUNSET  
TUESDAY. BRIEF HEAVY RAIN AND GUSTY OUTFLOW WIND ARE THE  
PRIMARY HAZARDS, WITH GUST POTENTIAL GREATEST IN THE SOUTH.  
 
- MOISTURE INCREASES FROM THE SOUTHWEST BEGINNING EARLY  
WEDNESDAY MORNING AND SPREADS NORTH THROUGH THE DAY. SHOWERS  
AND THUNDERSTORMS BECOMING WIDESPREAD AS THE DAY PROGRESSES.  
 
- THE BULK OF THE MONSOON MOISTURE SHIFTS EAST BEGINNING  
THURSDAY, WHICH DECREASES RAIN CHANCES WHILE ALLOWING FOR  
WARMER TEMPERATURES TO RETURN TO THE REGION. READINGS WILL  
LIKELY REACH THE 90S AND LOWER 100S SATURDAY AND SUNDAY.  
 
 
   
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 /06Z TAFS THROUGH 06Z THURSDAY/  
 
ISSUED AT 1005 PM MDT TUE JUL 28 2026  
 
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL TERMINALS  
THROUGH THE TAF PERIOD. CONDITIONS WILL REMAIN DRY THROUGH THE  
REST OF THE NIGHT, AS CLOUDS INCREASE FROM THE SOUTH-SOUTHWEST  
WITH SCT-OVC FL100-150 SKIES OVER THE SOUTHERN HALF OF THE  
FORECAST AREA BY SUNRISE WEDNESDAY. SHOWERS WILL BECOME  
POSSIBLE OVER SOUTHWESTERN PORTIONS OF THE FORECAST AREA AFTER  
15Z, BUT SHOULD NOT IMPACT KBPI/KPNA AND KRKS UNTIL AFTER 18Z.  
PROB30 GROUPS REMAIN IN THE FORECAST FOR ALL TERMINALS STARTING  
AROUND 20Z FOR THUNDERSTORMS OCCURRING ACROSS THE AREA THROUGH  
THE AFTERNOON. THE MAIN CONCERNS WILL BE FREQUENT LIGHTNING,  
GUSTY OUTFLOW WINDS OF 35KT, AND BRIEF PERIODS OF MODERATE TO  
HEAVY RAINFALL. HAVE ADDED ADDITIONAL PROB30 GROUPS FOR KCOD AND  
KJAC FOR CONTINUING SHOWERS THROUGH THE EVENING UNTIL 06Z  
THURSDAY. OTHERWISE, MOUNTAIN TOPS MAY BE OBSCURED AT TIMES  
IN ASSOCIATION WITH THE SHOWERS AND THUNDERSTORMS AND THE  
OVERALL INCREASED CLOUD COVER.  
 
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...LAVOIE/DZIEWALTOWSKI  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab WY Page
Main Text Page