260
FXUS65 KRIW 292358
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
558 PM MDT TUE SEP 29 2026
KEY MESSAGES
- COOL AND DRY TONIGHT. A FEW CLOUDS ACROSS FAR SOUTHERN
PORTIONS OF THE AREA.
- A WEAK COLD FRONT WILL BRING SOMEWHAT COOLER TEMPERATURES
THURSDAY, WITH A FEW SHOWERS POSSIBLE IN NORTHERN WYOMING. A
FEW SHOWERS POSSIBLE IN NORTHERN WYOMING FRIDAY AS WELL.
- MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THE NEXT SEVEN DAYS
WITH ODDS FAVORING DRY CONDITIONS AND ABOVE NORMAL
TEMPERATURES.
UPDATE
ISSUED AT 1108 AM MDT TUE SEP 29 2026
NO MAJOR CHANGES TO THE FORECAST THIS AFTERNOON OR TONIGHT.
AREAS OF FOG OVER THE WESTERN VALLEYS AND THE GREEN RIVER BASIN
WILL DISSIPATE BY NOON. PRECIPITATION IS EXPECTED TO STAY WELL
TO THE SOUTH IN COLORADO THIS AFTERNOON AND TONIGHT. CONDITIONS
WILL REMAIN DRY WITH CLEAR SKIES AND MAINLY LIGHT WINDS THROUGH
WEDNESDAY.
DISCUSSION
ISSUED AT 117 AM MDT TUE SEP 29 2026
IT HAS BEEN AN ACTIVE FEW MONTHS, WITH EVERYTHING FROM ALL-TIME
RECORD HEAT TO A MONSOON THAT SEEMED LIKE IT NEVER WANTED TO
END (IT LOOKS LIKE IT HAS FINALLY ENDED, THANKFULLY), WITH
SEEMINGLY SOMETHING HAPPENING EACH DAY. YOU KNOW IT WOULDN'T BE
ONE OF MY DISCUSSIONS WITHOUT AN OLD MOVIE REFERENCE REFERRING
TO THE WEATHER PATTERN. AND TODAY, WE TURN TO AN 80S MOVIE
STARRING THE LATE, GREAT RODNEY DANGERFIELD WITH AN ASSIST FROM
JOE PESCI, THE MOVIE IS EASY MONEY. WHILE THE WEATHER WILL
LIKELY NOT BE COMPLETELY QUIET, THE GENERAL PATTERN WILL BE, AT
LEAST COMPARED TO MANY OF THE PREVIOUS WEEKS, EASY MONEY FOR
METEOROLOGISTS.
DRIER AIR IS CURRENTLY PRESSING SOUTHWARD INTO THE AREA FROM THE
NORTHWEST. THIS SHOULD BRING A PLEASANT, EARLY AUTUMN DAY TO MOST OF
THE AREA. THE EXCEPTION MAY BE SWEETWATER COUNTY, ESPECIALLY SOUTH
OF INTERSTATE 80. JUST ENOUGH MOISTURE MAY REMAIN THERE AND THEY MAY
BE ON THE EDGE OF THE MOISTURE FROM THE REMNANTS OF HURRICANE POLO
FOR THERE TO BE A FEW SHOWERS, ESPECIALLY IN THE MORNING. I ALSO
CAN'T RULE OUT AN ISOLATED SHOWER OR THUNDERSTORM HERE IN THE
AFTERNOON, BUT WITH THE CHANCE LESS THAN 1 OUT OF 10, WE LEFT THE
FORECAST DRY FOR NOW. MOST LOCATIONS SHOULD BE COMFORTABLY WARM,
WITH HIGHS GENERALLY 5 TO 10 DEGREES ABOVE NORMAL. WEDNESDAY ALSO
LOOKS LIKE A NICE AUTUMN DAY AS JUST ABOUT ALL GUIDANCE KEEPS THE
MOISTURE FROM POLO TO THE SOUTH ACROSS COLORADO.
THINGS COULD GET A LITTLE MORE ACTIVE ON THURSDAY AS A COLD FRONT
DROPS IN FROM THE NORTH. THE FRONT IS OF CONTINENTAL ORIGIN AND
DOESN'T HAVE A TON OF MOISTURE TO WORK WITH THOUGH. ONE THING IT
WILL HAVE IS A JET STREAK MOVING ALONG IT AS IT DROPS
SOUTHWARD. THIS MAY BRING ENOUGH LIFT TO PRODUCE SOME SHOWERS
THURSDAY OR THURSDAY NIGHT. MOST GUIDANCE SHOWS THIS LARGELY
NORTH OF WYOMING, BUT IF THE FRONT CAN DROP A BIT FURTHER SOUTH,
IT COULD IMPACT PORTIONS OF BIG HORN AND JOHNSON COUNTIES WITH
SOME SHOWERS. POPS ARE LOW FOR NOW THOUGH, GENERALLY LESS THAN
1 OUT OF 3. WIND MAY ALSO NEED TO BE INCREASED A BIT WITH THE
COLD ADVECTION PATTERN, BUT HIGH WIND IS NOT EXPECTED. THE MAIN
IMPACT WILL BE TO KNOCK TEMPERATURES DOWN SOMEWHAT, ESPECIALLY
IN A PLACE LIKE BUFFALO WHICH COULD BE 10 TO 15 DEGREES COOLER
THAN ON WEDNESDAY. MOST LOCATIONS EAST OF THE DIVIDE WILL
GENERALLY BE 5 TO 10 DEGREES COOLER ON THURSDAY AND POSSIBLY
FRIDAY AS WELL.
ANOTHER FRONT MAY GET CLOSE TO WYOMING FRIDAY NIGHT OR
SATURDAY, BUT THIS ONE IS EVEN DRIER AND WOULD ONLY PRODUCE VERY
ISOLATED SHOWERS, AGAIN MAINLY ACROSS NORTHERN WYOMING.
FOLLOWING THAT, A VAST MAJORITY OF GUIDANCE THEN REBUILDS A
STRONG RIDGE ACROSS THE WESTERN UNITES STATES, BRINGING A
PROLONGED PERIOD OF ABOVE NORMAL TEMPERATURES WITH MAINLY DRY
CONDITIONS. SOME GUIDANCE IS SHOWING A SHORTWAVE POSSIBLY
PRODUCING A FEW SHOWERS ON MONDAY, BUT THIS IS HIGHLY UNCERTAIN
THIS FAR OUT. SO, OTHER THAN A COUPLE OF WEAK SYSTEMS, THE
WEATHER LOOKS RELATIVELY UNEVENTFUL ACROSS THE AREA. AND, THERE
ARE NO SIGNS OF A BIG COOLDOWN WITH TEMPERATURES GENERALLY
REMAINING NEAR TO ABOVE NORMAL OVER THE NEXT SEVERAL DAYS.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 538 PM MDT TUE SEP 29 2026
VFR CONDITIONS THROUGH THE PERIOD, WITH A MAINLY CLEAR SKY. LIGHT
WINDS PREVAIL OVERNIGHT AND INTO WEDNESDAY. NO PRECIPITATION IS
EXPECTED 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...LAVOIE
DISCUSSION...HATTINGS
AVIATION...WITTMANN
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