070
FXUS65 KRIW 091734
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1134 AM MDT SUN AUG 9 2026
KEY MESSAGES
- HOT, DRY, AND BREEZY CONDITIONS CONTINUE THROUGH TUESDAY. THIS
WILL LEAD TO CONTINUED NEAR-CRITICAL TO CRITICAL FIRE WEATHER
CONDITIONS. RFW'S REMAIN IN EFFECT THROUGH 9 PM TODAY.
- SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
ACROSS SOUTHERN PORTIONS OF THE AREA THIS AFTERNOON AS WELL AS
MONDAY AFTERNOON. MOST SHOWERS WILL REMAIN VIRGA WITH GUSTY
DOWNDRAFT/OUTFLOW WIND OF 40-55 MPH THE MAIN HAZARD.
- WILDFIRE SMOKE CONTINUES TO STREAM INTO THE AREA EARLY THIS
WEEK LEADING TO REDUCED VISIBILITY AND POOR AIR QUALITY. AIR
QUALITY ALERTS REMAIN IN EFFECT THROUGH NOON TOMORROW.
- A WELCOME PATTERN CHANGE APPEARS LIKELY (70%) LATE THIS WEEK
AS MOISTURE BRINGS BETTER CHANCES FOR RAIN AND MUCH COOLER
TEMPERATURES.
UPDATE
ISSUED AT 1121 AM MDT SUN AUG 9 2026
THE FIRST STORM OF THE DAY HAS DEVELOPED IN SOUTHWEST SWEETWATER
COUNTY IN THE PAST HALF HOUR. MORE ISOLATED STORMS AND SCATTERED
RAIN SHOWERS WILL DEVELOP ACROSS SOUTHERN WYOMING THIS
AFTERNOON. MOST RAIN SHOWERS WILL REMAIN VIRGA AND VERY LITTLE
RAIN WILL REACH THE GROUND WITH THE STRONGEST SHOWERS/STORMS. IT
SHOULD BE NO SURPRISE THAT THE MAIN HAZARD TODAY WILL BE STRONG
DOWNDRAFT/OUTFLOW WIND FROM SHOWERS AND STORMS. THE RED FLAG
WARNINGS REMAIN IN PLACE THROUGH 9 PM THIS EVENING AS THE
COMBINATION OF HOT TEMPERATURES, VERY LOW HUMIDITY, AND BREEZY
WIND LEADS TO CRITICAL FIRE WEATHER CONDITIONS. MORE RED FLAG
WARNINGS MAY BE NEEDED FOR SOME ZONES MONDAY AND TUESDAY, BUT
FOR NOW DID NOT ISSUE DUE TO CURRENT RFWS IN EFFECT. IT SEEMS
THAT MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT ON GOOD
MOISTURE MOVING INTO THE AREA LATE THIS WEEK WITH MUCH BETTER
CHANCES FOR ACTUAL RAIN IN THE AREA. STILL TRYING TO HAMMER DOWN
THE DETAILS AT THIS TIME.
DISCUSSION
ISSUED AT 1256 AM MDT SUN AUG 9 2026
IT IS SAID THAT THE WEATHER PATTERN OFTEN REPEATS ITSELF. AND THE
PATTERN FOR THIS WEEK IS NO EXCEPTION. THE PAST COUPLE OF HEAT WAVES
WE HAD, THE WARMEST TEMPERATURES OCCUR OVER THE WEEKEND. HOT
TEMPERATURES LINGER INTO EARLY THE NEXT WEEK. AND THEN, MONSOONAL
MOISTURE REALLY BEGINS TO INCREASE AND WITH THE INCREASED CLOUD
COVER AND PRECIPITATION COVERAGE, TEMPERATURES DROP OFF, PROBABLY TO
BELOW NORMAL LEVELS BY THE END OF THE WEEK. AND, WITH WHAT HAPPENED
WITH THE BEST COUPLE OF MONSOONAL EVENTS, THE MODELS WILL HANDLE THE
PLACEMENT AND TIMING OF THE SHOWERS RATHER POORLY.
AND EXAMPLE IS TONIGHT, THEY DID HAVE THE VIRGA SHOWERS IN SOUTHERN
WYOMING. BUT THEY HAD NOTHING IN NORTHERN WYOMING. THE ALSO DID NOT
HAVE ANYTHING LINGERING ACROSS THE SOUTH AFTER MIDNIGHT, AND WE HAVE
THAT AS WELL. HOWEVER, AS FOR TODAY, THE LARGE MAJORITY OF THE AREA
WILL HAVE ANOTHER HOT AND DRY DAY, ALTHOUGH SOMEWHAT MORE CLOUD
COVER COULD LOWER TEMPERATURES A DEGREE OR TWO. IT WILL STILL BE
ABOVE NORMAL ACROSS MOST OF THE AREA THOUGH. AND LIKE YESTERDAY,
CRITICAL FIRE WEATHER IS LIKELY ACROSS MOST OF THE AREA WITH
HUMIDITY REMAINING BELOW 15 PERCENT AND A GUSTY BREEZE DEVELOPING IN
THE AFTERNOON. AS FOR CONVECTION, WE DID INCREASE COVERAGE SOMEWHAT,
EXPANDING IT INTO THE SOUTHERN WIND RIVER BASIN THIS AFTERNOON. LIKE
YESTERDAY, WITH THE VERY DRY LOW LEVELS, IT WOULD LIKELY ONLY BE
VIRGA. HOWEVER, WITH THE LARGE DEW POINT DEPRESSIONS (UP TO 70
DEGREES IN SOME LOCATIONS), WE COULD HAVE SOME STRONG WIND GUSTS,
POSSIBLY OVER 50 MPH. THIS HAS THE POTENTIAL TO BE A "LITTLE GREEN
BLOB" DAY. COVERAGE STILL LOOKS SPARSE THOUGH, GENERALLY LESS THAN A
1 OUT OF 4 CHANCE. AND, WE WILL CONTINUE TO HAVE AREAS OF SMOKE
BRINGING POOR AIR QUALITY.
MONDAY AND TUESDAY LOOK FAIRLY SIMILAR. WITH 700 MILLIBAR
TEMPERATURES STILL IN THE 18 TO 19 CELSIUS RANGE, IT WILL CONTINUE TO
BE RATHER HOT, WITH TEMPERATURES SIMILAR TO TODAY'S HIGHS. AS FOR
CONVECTION, THERE IS ACTUALLY DECENT MODEL AGREEMENT IN KEEPING THE
BULK OF THE MONSOONAL MOISTURE SOUTH OF WYOMING. THE MAIN AREA OF
CONCERN WOULD BE ACROSS SOUTHERN WYOMING, BUT EVEN HERE CHANCES LOOK
FAIRLY SMALL, GENERALLY LESS THAN A 1 OUT OF 4 CHANCE. I CAN'T RULE
ONE OUT IN SOME OF THE NORMAL DEVELOPMENT AREAS, LIKE THE WASHAKIE
NEEDLES AT THE SOUTHERN END OF THE ABSAROKAS, BUT WITH THE CHANCE
LESS THAN 1 OUT OF 6 WE KEPT THE FORECAST DRY FOR NOW. AS FOR FIRE
WEATHER CONCERNS, THERE COULD STILL BE SOME. RELATIVE HUMIDITY WILL
STILL BE IN THE TEENS BUT A BIT HIGHER THAN OVER THE WEEKEND. WIND
ALSO LOOKS BORDERLINE. SO, WE WILL NOT EXTEND THE WARNINGS AT THIS
TIME, BUT FUTURE SHIFTS MAY WANT TO TAKE ANOTHER LOOK AT THINGS.
THE PATTERN BEGINS TO SHIFT ON WEDNESDAY. A WEAK COLD FRONT WILL
APPROACH FROM THE NORTHEAST AND BRING COOLER TEMPERATURES STARTING
ON WEDNESDAY BUT ESPECIALLY FOR THE END OF THE WEEK, WITH BELOW
NORMAL TEMPERATURES FOR MANY FROM THURSDAY INTO NEXT WEEK. AND,
MOISTURE WILL INCREASE STARTING ON WEDNESDAY. THIS WILL BRING AN
INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA INTO
THE WEEKEND. PRECIPITABLE WATERS LOOK TO RISE ABOVE 150 PERCENT OF
NORMAL STARTING ESPECIALLY ON THURSDAY AND CONTINUE INTO THE
WEEKEND. AT THIS POINT, IT DOES NOT LOOK AS MOIST AS DURING THE
MIDDLE OF JULY, WITH PRECIPITABLE WATERS MAXING OUT AT AROUND 25
PERCENT LESS THAN THAT TIME PERIOD. AS FOR DETAILS, THEY ARE STILL
UNCERTAIN. THE MONSOON WILL BE ENHANCED BY A FEW SHORTWAVES PASSING
THROUGH BUT THESE ARE DIFFICULT TO TIME, ESPECIALLY TOWARD THE END
OF THE WEEK. THERE IS SOME AGREEMENT WITH MOST ACTIVITY BRING EAST
OF THE DIVIDE ON WEDNESDAY, PAST THAT TIME DETAILS BECOME FAR MORE
UNCERTAIN IN REGARDS TO PLACEMENT AND DAY OF MOST NUMEROUS ACTIVITY.
AS FOR POSSIBLY HEAVY RAIN AND FLOODING, THERE IS ONE DIFFERENCE.
MID LEVEL FLOW WILL BE SOMEWHAT STRONGER THAN A FEW WEEKS AGO, WITH
20 TO 35 KNOTS OF FLOW AT 500 MILLIBARS. THIS SHOULD ALLOW STORMS TO
HAVE MORE MOVEMENT AND REDUCE THE RISK SOMEWHAT. THIS, ALONG WITH
FACT THAT THE RECENT DRY WEATHER MEANS THERE IS PLENTY OF ROOM IN
THE SOIL. HOWEVER, WE DO NEED THE RAIN AND WE WILL TAKE WHAT WE CAN
GET, AS LONG IT IS NOT TOO MUCH ALL AT ONCE.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1100 AM MDT SUN AUG 9 2026
VFR CONDITION SHOULD PREVAIL THROUGH THE PERIOD. HOWEVER, WITH
WILDFIRE SMOKE OVER THE AREA, VISIBILITIES COULD DROP TO AROUND 5SM
OR 6SM AT TIMES. SMOKE MAY SEE SLIGHT IMPROVEMENT TOWARD THE VERY
END OF THE PERIOD, ESPECIALLY ACROSS SOUTHERN WYOMING. FOR TODAY,
VIRGA OR LIGHT SHOWERS, AND POSSIBLY AN ISOLATED THUNDERSTORM, IS
POSSIBLE FOR SOUTHERN WYOMING. CONFIDENCE IS NOT HIGH IN ANY SITE
GETTING IMPACTED, THOUGH KRKS WOULD BE THE MOST LIKELY. THE NORTHERN
EXTENT OF CHANCES STOPS AROUND KPNA AND KRIW. OUTFLOW GUSTS AROUND
40 KNOTS ARE POSSIBLE WITH ANY SHOWER OR STORM THAT DOES OCCUR,
THOUGH AN ISOLATED GUST TO 60 KNOTS CANNOT BE RULED OUT AROUND KRKS.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON ICING AND TURBULENCE FORECASTS.
FIRE WEATHER
ISSUED AT 1256 AM MDT SUN AUG 9 2026
TODAY WILL BE SIMILAR TO SATURDAY. A COMBINATION OF HOT
TEMPERATURES, HUMIDITY FALLING TO AROUND AND UNDER 10 PERCENT
AND A GUSTY AFTERNOON BREEZE WILL BRING ELEVATED TO CRITICAL
FIRE WEATHER TO MOST OF WESTERN AND CENTRAL WYOMING, ESPECIALLY
IN THE AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS IN CENTRAL
AND SOUTHERN WYOMING WILL BRING LITTLE RAIN, BUT COULD BRING
WIND GUSTS OVER 40 MPH AND POSSIBLE LIGHTNING STRIKES. HOT
WEATHER CONTINUES MONDAY AND TUESDAY ALTHOUGH SOMEWHAT HIGHER
HUMIDITY MAY EASE FIRE WEATHER CONCERNS SOMEWHAT.
RIW WATCHES/WARNINGS/ADVISORIES
AIR QUALITY ALERT UNTIL NOON MDT MONDAY FOR WYZ001>020-022>030.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ140-
275>283-285>289-300.
UPDATE...STRAUB
DISCUSSION...HATTINGS
AVIATION...WITTMANN
FIRE WEATHER...HATTINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page