788
FXUS65 KRIW 070038
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
638 PM MDT MON JUL 6 2026
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE THIS EVENING WITH
STRONGER STORMS POSSIBLE UNTIL 9 PM. THE BEST CHANCES FOR
SHOWERS AND STORMS WILL BE ACROSS WESTERN, CENTRAL, AND
NORTHERN WYOMING.
- A FEW STRONG TO SEVERE STORMS CANNOT BE RULED OUT, WITH THE
MAIN CONCERNS BEING FREQUENT LIGHTNING, STRONG WIND GUSTS
AROUND 50 MPH, AND PEA- TO DIME-SIZED HAIL.
- ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TUESDAY, ALTHOUGH
COVERAGE WILL BE LESS WIDESPREAD. CHANCES FURTHER DECREASE
WEDNESDAY EXCEPT ACROSS NORTH-CENTRAL WYOMING.
- WARM AND DRY CONDITIONS RETURN FOR THE SECOND HALF OF THE WEEK
WITH RECORD-BREAKING HEAT POSSIBLE THE WEEKEND OF JULY 11-12.
UPDATE
ISSUED AT 1210 PM MDT MON JUL 6 2026
MORNING CLOUD COVER HAS DELAYED CUMULUS GROWTH MONDAY MORNING, BUT
SATELLITE IMAGERY IS SHOWING CLEARING AND MORE SUNSHINE AT MIDDAY.
THE SHORTWAVE RESPONSIBLE FOR THE CLOUD COVER WAS LOCATED OVER
SOUTHEAST OREGON LATE MONDAY MORNING, WHILE HIGH PRESSURE WAS
PRESENT OVER THE FOUR CORNERS REGION. SOUTHWEST FLOW BETWEEN
THESE TWO FEATURES WAS FUNNELING MOISTURE NORTHEASTWARD ACROSS
UTAH INTO IDAHO AND WYOMING. THIS MOISTURE FEED CONTINUES
THROUGH THE EVENING AND OVERNIGHT HOURS AS THE SHORTWAVE SLOWLY
TRACKS TO THE BITTERROOTS TONIGHT. THE MOISTURE AND INSTABILITY,
OWING TO DAYTIME HEATING, COMBINE WITH SOME FAVORABLE JET
DYNAMICS TO FAVOR STRONGER CONVECTION LATER MONDAY AFTERNOON AND
EVENING BEFORE SLOWLY DECREASING IN COVERAGE AND INTENSITY
TOWARD MIDNIGHT TUESDAY.
SHOWERS AND STORMS ERUPT BETWEEN 1 AND 3 PM MONDAY WITH STRONGER
STORMS DEVELOPING AFTER 4 PM AND PERSISTING UNTIL 8 OR 9 PM.
DEWPOINTS HAVE RISEN INTO THE MID 40S TO AROUND 50 ACROSS THE
BIGHORN BASIN AND I-25 CORRIDOR LATE MONDAY MORNING. THIS SHOULD
SET THE STAGE FOR MORE ROBUST CONVECTION LATER THIS AFTERNOON
ACROSS THIS REGION, WHICH IS HIGHLIGHTED WITHIN A MARGINAL RISK
FOR SEVERE THUNDERSTORMS IN SPC'S DAY 1 OUTLOOK. THE PRIMARY
HAZARD WILL BE STRONG WIND GUSTS, ALTHOUGH THE INCREASED
MOISTURE, AT THE SURFACE AND ALOFT, COULD LEAD TO SMALL HAIL
EAST OF THE CONTINENTAL DIVIDE. THE LOW DEWPOINTS AND
INVERTED-V PROFILES ACROSS SOUTHWEST WYOMING LIMIT THE THREAT TO
STRONG OUTFLOW WIND EVEN FROM WEAKER SHOWERS. HIGHER DEWPOINTS
AND INCREASED PRECIPITABLE WATER VALUES ACROSS MAINLY THE NORTH
HALF OF THE STATE SHOULD ALLOW FOR BRIEF MODERATE RAIN WITH THE
STRONGER STORMS. STORM MOTION WILL BE NORTHEAST AROUND 25 MPH.
DRIER AIR ARRIVES FROM THE WEST LATE TONIGHT AND TUESDAY AS THE
SHORTWAVE TRAVELS EAST THROUGH MONTANA. COVERAGE AND INTENSITY
OF SHOWERS AND STORMS WILL BE LESS TUESDAY AFTERNOON, ALTHOUGH
OUTFLOW WIND WILL REMAIN A HAZARD.
DISCUSSION
ISSUED AT 243 AM MDT MON JUL 6 2026
SUNDAY SAW SOME OF THE WARMEST TEMPERATURES OF THE SEASON SO FAR
ACROSS THE COWBOY STATE. PORTIONS OF THE BIGHORN BASIN FLIRTED WITH
THE CENTURY MARK, WHILE CENTRAL WY SAW HIGHS IN THE MID TO UPPER 90S
AND LOCATIONS WEST OF THE DIVIDE HIT THE UPPER 80S TO EVEN 90F.
THESE WARM TEMPERATURES MAY BE A BRIEF HINT AT WHAT COULD
POSSIBLY BE ON THE HORIZON. HOWEVER, THERE IS STILL A WHOLE WEEK
OF WEATHER TO ADDRESS BEFORE THAT.
THE WORK WEEK WILL START WITH A NICE BREAK FROM THE HEAT AND
POSSIBLY SOME PRECIPITATION ACROSS THE CWA TODAY. A WEAK COLD FRONT
HAS WORKED ITS WAY ACROSS NORTHERN WY THIS MORNING AND IS LIKELY TO
REMAIN STATIONARY OVER THE NORTHERN PORTION OF THE STATE. THE
FRONTAL PASSAGE HAS BROUGHT SOME COOLER TEMPERATURES, BUT MORE
IMPORTANTLY INCREASED DEWPOINTS MAINLY OVER NORTHERN WY. HIGH
TEMPERATURES ARE EXPECTED TO GET INTO THE UPPER 80S TO LOWER
90S EAST OF THE DIVIDE AND LOW TO MID 80S WEST OF THE DIVIDE. A
SHORTWAVE WILL GRADUALLY START MAKING ITS WAY ACROSS NORTHERN
IDAHO, PORTIONS OF MONTANA, AND NORTHWESTERN WYOMING THIS
AFTERNOON AND EVENING. THIS WILL BEGIN TO INITIATE CONVECTIVE
DEVELOPMENT, WHILE ALSO SLOWLY PUSHING IN ABOVE NORMAL PWATS TO
MUCH OF THE AREA. A FEW ISOLATED SHOWERS CANNOT BE RULED OUT
DURING THE MORNING HOURS MAINLY OVER WESTERN WY. CONVECTION
REALLY KICKS OFF AFTER NOON, ACROSS WESTERN/CENTRAL WY WITH
SHOWERS AND STORMS GRADUALLY SPREADING NORTH THROUGH THE
AFTERNOON AND EVENING. PRECIPITATION CHANCES WILL BE THE
GREATEST ACROSS WESTERN, CENTRAL, AND NORTHERN WY. CHANCES RANGE
FROM 20 TO 40% FOR MUCH OF THE PREVIOUSLY MENTIONED AREA, WITH
HIGHER CHANCES OF 30 TO 60% OVER NORTHERN WY. DRIER AIR WILL
LIKELY HINDER PRECIPITATION CHANCES FROM ROCK SPRINGS TO CASPER.
THE STORM PREDICTION CENTER HAS HIGHLIGHTED PORTIONS OF
NORTHERN AND CENTRAL WY THIS AFTERNOON/EVENING FOR A MARGINAL
RISK (1 OUT OF 5) OF SEVERE STORMS. THE MAIN HAZARDS BEING
STRONG GUSTY WINDS AND POSSIBLY HAIL GREATER THAN 1 INCH. THE
GREATEST INSTABILITY WILL LIKELY REMAIN ACROSS NORTHERN WY,
WHERE DEWPOINTS MAY NEAR 50F. CAPE VALUES LOOK TO RANGE FROM 500
TO POSSIBLY 1,000 J/KG OVER THIS AREA. LESSER CAPE AROUND 500
J/KG WILL BE ACROSS MUCH OF CENTRAL AND SOUTHWESTERN WY. THE
NEARING SHORTWAVE LOOKS TO CREATE SOME FAVORABLE 700-500 MB
SHEAR WITH VALUES OF 30-40 KTS ACROSS PORTIONS OF CENTRAL AND
ESPECIALLY NORTHERN WY. FAVORABLE STEEP LAPSE RATES ARE LIKELY
TO BE IN PLACE LEADING TO THE POTENTIAL FOR A STRONG TO SEVERE
STORM OR TWO DURING THE MID TO LATE AFTERNOON. PWAT VALUES LOOK
TO BE NEARLY 100-150% ABOVE NORMAL, SO SOME STORMS ESPECIALLY
ACROSS NORTHERN WY MAY BE CAPABLE OF PRODUCING A PERIOD OF
MODERATE TO HEAVY RAINFALL AS WELL. OVERALL, SCATTERED SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND
EVENING MAINLY ACROSS WESTERN, CENTRAL, AND NORTHERN WY. THE
MAIN CONCERNS WILL BE FREQUENT LIGHTNING, STRONG GUSTY WINDS,
SMALL TO LARGE HAIL (~1"), AND POSSIBLY A FEW MODERATE TO HEAVY
RAIN SHOWERS. ONE THING TO MENTION IS THAT DEWPOINT DEPRESSIONS
ACROSS SWEETWATER AND PORTIONS OF NATRONA/FREMONT COUNTY WILL
LIKELY BE AROUND 45-55F. THIS MEANS IF ANY STORMS DO DEVELOP
NEARBY, WHICH DOES NOT LOOK LIKELY (10-20%), THERE COULD BE A
FEW STRONG GUSTY OUTFLOW WINDS OF 45 MPH OR MORE.
SHOWERS AND WEAKENING STORMS MAY LINGER AFTER SUNSET, BUT
SHOULD GRADUALLY DISSIPATE THROUGH THE LATE EVENING MONDAY INTO
THE EARLY MORNING HOURS TUESDAY. SOME CAMS DO SHOW ANOTHER ROUND
OF LIGHT SHOWERS MOVE THROUGH WESTERN WY DURING THE EARLY
MORNING HOURS TUESDAY. CURRENTLY, CHANCES SIT AROUND 20-40% WITH
LESSER CHANCES EAST OF THE DIVIDE. TUESDAY COULD SEE ANOTHER
DAY OF SCATTERED SHOWERS AND THUNDERSTORMS, BUT THE CAVEAT
BEING WIDESPREAD ABOVE NORMAL MOISTURE. SOME STRONG TO SEVERE
STORMS CANNOT BE RULED OUT WITH THE MAIN CONCERNS LIKELY BEING
STRONG GUSTY WINDS AND HAIL. DUE TO ABOVE NORMAL PWATS, SOME
MINOR FLOODING CANNOT BE RULED OUT, ESPECIALLY IN POOR DRAINAGE
AREAS. TEMPERATURES TUESDAY LOOK TO GET INTO THE MID TO UPPER
80S EAST OF THE DIVIDE AND LOW 80S WEST OF THE DIVIDE.
AFTER TUESDAY, MODELS ARE TRENDING TOWARDS A DRIER AND WARMER
SECOND HALF OF THE WORK WEEK. TEMPERATURES LOOK TO GRADUALLY
WARM BACK INTO THE LOW 90S EAST OF THE DIVIDE AND MID TO UPPER
80S WEST OF THE DIVIDE. SOME SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT WEDNESDAY, BUT AT THIS TIME CHANCES FOR MOISTURE LOOK
SLIM.
LONG RANGE FORECAST MODELS HAVE BEEN HINTING AT THIS FOR A LITTLE
WHILE NOW AND THAT "THING" IS A RATHER ANOMALOUSLY POTENT RIDGE
BUILDING OVER THE WESTERN/CENTRAL CONUS. WHILE STILL NEARLY A
WEEK OUT, THERE IS TIME FOR THINGS TO CHANGE BUT AT THE MOMENT,
THERE IS GOOD CONSENSUS AMONG LONG RANGE FORECAST MODELS.
TEMPERATURES START TO TURN UP FRIDAY WITH CURRENT HIGHS GETTING
INTO THE MID TO UPPER 90S EAST OF THE DIVIDE AND UPPER 80S TO
LOWER 90S WEST OF THE DIVIDE. TEMPERATURES CONTINUE TO SOAR FOR
THE WEEKEND WITH PROBABILISTIC MODELS SHOWING A 30-70% CHANCE
FOR HIGHS NEAR OR ABOVE 100F EAST OF THE DIVIDE AND 40-80%
CHANCE FOR HIGHS AROUND 105F FOR PORTIONS OF THE BIGHORN BASIN.
LOCATIONS WEST OF THE DIVIDE DO NOT LOOK TO BE SPARED WITH A
20-50% CHANCE OF HIGHS TO GET INTO THE MID 90S. THERE IS
CERTAINLY POTENTIAL TO SEE WIDESPREAD DAILY HIGH TEMPERATURE
RECORDS BROKEN AND THE POTENTIAL FOR ALL TIME HIGH TEMPERATURE
RECORDS TO BE BROKEN TOO. OVERNIGHT TEMPERATURES DO NOT LOOK TO
COOL ALL TOO MUCH WITH BREEZY WINDS KEEPING LOWS ABOVE 60 ACROSS
LOCATIONS EAST OF THE DIVIDE. OVERALL, THERE IS STILL TIME FOR
THINGS TO SHIFT AND CHANGE. HOWEVER, THERE IS CERTAINLY AN
INCREASING POTENTIAL FOR A RECORD BREAKING PROLONGED PERIOD OF
HEAT. SO UNLIKE THAT ONE SONG, THE DOG DAYS ARE NOT OVER, SO YOU
BETTER BE SURE TO CHECK THAT A/C IS WORKING PROPERLY!
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 414 PM MDT MON JUL 6 2026
THE MAJORITY OF SHOWERS AND STORMS END BY 03Z/TUES. HOWEVER,
LINGERING SHOWERS, AND A POSSIBLE THUNDERSTORM, CONTINUE ACROSS
PORTIONS OF WESTERN WYOMING THROUGH THE NIGHT, WITH PROB30
GROUPS KEPT AT KCOD AND KJAC. MOST OF THESE SHOWERS SHOULD BE
DONE BY 08Z/TUES, BUT A FEW MAY LINGER AS LATE AS 12Z/TUES.
FOR TUESDAY, STORMS BEGIN TO INITIATE AROUND 19Z, WITH CHANCES
THROUGH THE AFTERNOON. GIVEN THE RANGE OUT, HAVE LEFT PROB30
GROUPS FOR NOW FOR SITES WITH THE BEST CHANCES OF ISOLATED
SHOWERS OR STORMS.
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...CNJ
DISCUSSION...DZIEWALTOWSKI
AVIATION...LAVOIE/WITTMANN
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