743
FXUS65 KRIW 081734
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1134 AM MDT FRI MAY 8 2026
KEY MESSAGES
- MOSTLY SUNNY, WARM TODAY WITH HIGHS IN THE UPPER 60S AND LOW
70S. ISOLATED (10%-15%) VIRGA/LIGHT SHOWER POTENTIAL ACROSS
YELLOWSTONE NATIONAL PARK AND THE BIGHORN BASIN AFTER 5PM/6PM.
- EXPECT HIGHS IN THE 60S ON SATURDAY WITH BREEZY 20 TO 30 MPH
WINDS. SHOWER AND THUNDERSTORM CHANCES (40% TO 80%) ALONG AND
EAST OF THE DIVIDE, ESPECIALLY ACROSS JOHNSON AND NATRONA
COUNTIES, MUCH OF SATURDAY.
- DRY AND WARM SUNDAY THROUGH A MAJORITY OF NEXT WEEK WITH
WIDESPREAD HIGHS IN THE 70S AND 80S. BREEZY WINDS AND MINIMUM
RELATIVE HUMIDITY VALUES BELOW 15% WILL CONTRIBUTE TO
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS.
DISCUSSION
ISSUED AT 100 AM MDT FRI MAY 8 2026
NORTHWEST FLOW ALOFT CONTINUES ACROSS THE CWA AS DEPICTED ON WV
IMAGERY WITH THE PFJ NOW RETREATED TO THE NORTHEAST COMING OUT
OF CANADA THROUGH EASTERN MONTANA TO NORTHEASTERN WY TO THE
GREAT PLAINS. IR SHOWS SUBSIDENCE PUSHING IN FROM THE WEST AS
THE AMPLE CLOUD COVER IS PUSHING EAST OUT OF THE AREA BY SUNRISE
FRIDAY MORNING. A FEW SCATTERED SHOWERS LINGER ACROSS EASTERN
FREMONT AND INTO NATRONA COUNTY THAT WILL DIMINISH AND EXIT THE
CWA BEFORE SUNRISE AS WELL.
CONVERGENCE AND DRY SLOTTING EXPECTED FOR FRIDAY WITH WARMER
TEMPERATURES (~5 DEGREES WARMER THAN THURSDAY) WITH DRY
CONDITIONS EXPECTED. SOME BREEZY WINDS WEST OF THE DIVIDE AND
ACROSS THE WIND CORRIDOR, BUT NOTHING EXCEPTIONAL WITH AN
OVERALL WEAK TO MODERATE PRESSURE GRADIENT ACROSS THE CWA. THE
NEXT SUBTLE SHORTWAVE WILL PROPAGATE DOWN THE NORTHWEST FLOW
DROPPING A WEAK FRONTAL BOUNDARY IN FROM THE NORTH COME SATURDAY
MORNING. THIS WILL BRING SOME SCATTERED RAIN SHOWERS AND
ISOLATED THUNDERSTORMS BY SATURDAY AFTERNOON AND EVENING WITH
40-50% COVERAGE AND CONFIDENCE A BIT MORE NORTHEAST THAN IT WAS
THURSDAY. THE STRONGEST STORMS LOOK TO BE EAST OF THE BIGHORNS
FOR JOHNSON/NATRONA COUNTIES WHERE CAPE VALUES LOOK TO BE MORE
INTRIGUING FOR WYOMING STANDARDS ~250-350 J/KG. GUSTY OUTFLOWS
LOOK TO BE THE HAZARD OUTSIDE OF ANY LIGHTNING TO OCCUR AND
SOMETHING TO KEEP AN EYE ON. NOTHING OF HIGH SIGNIFICANCE BUT
ANY RAINFALL WILL HELP IN THESE AREAS. REGARDLESS, ONCE THE SUN
SETS, ANY LINGERING SHOWER ACTIVITY WILL WEAKEN AND EXIT TO THE
EAST BEFORE MIDNIGHT AND DRY OUT COME SUNDAY MORNING.
SUNDAY AND INTO NEXT WEEK WILL SEE A STRONGER UPPER LEVEL RIDGE
TO BUILD IN TO BE MORE ORIENTED ACROSS THE ROCKIES. THIS WILL
BRING MUCH WARMER TEMPERATURES AND DRY CONDITIONS FOR SEVERAL
DAYS. AFTERNOON HIGH TEMPERATURES EAST OF THE DIVIDE LOOK TO
PUSH WELL INTO THE 80S WITH 70S TO THE WEST. BREEZY CONDITIONS
WILL LEAD TO ELEVATED FIRE WEATHER CONDITIONS DUE TO THE LOW RH
VALUES AND WARMER TEMPERATURES, EVEN WITH GREENUP NOW ONGOING
FOR ALL ZONES. THE NEXT WEATHER SYSTEM OF NOTE LOOKS TO BE BY
WEEK'S END LATE THURSDAY INTO FRIDAY THAT SHOULD BRING A
REPRIEVE FROM THE WARMER TEMPERATURES AND INCREASING
PRECIPITATION CHANCES ONCE AGAIN.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1133 AM MDT FRI MAY 8 2026
VFR CONDITIONS ARE EXPECTED ACROSS THE REGION OVER THE NEXT 24
HOURS. MOSTLY CLEAR SKIES THIS AFTERNOON, WITH INCREASING CLOUD
COVER FOR THE NORTHERN HALF OF WYOMING THIS EVENING.
ISOLATED RAIN SHOWERS DEVELOP OVERNIGHT FOR THE NORTHERN HALF
OF THE STATE, WITH MID-LEVEL CLOUD LAYERS. THERE IS A 50% CHANCE
OF BRIEF HIT-OR-MISS SHOWERS AFFECTING WRL AND CPR NEAR AND AFTER
SUNRISE SATURDAY, BUT HEAVY RAIN IS NOT EXPECTED. WINDS SHIFT
TO BECOME NORTHERLY SATURDAY MORNING AS A SUBTLE COLD FRONT
PUSHES SOUTHWARD INTO THE REGION FROM MONTANA, MAINLY AFFECTING
LOCATIONS EAST OF THE CONTINENTAL DIVIDE. GUSTS RANGE FROM 20
TO 30 KT WITH THIS COLD FRONT.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...LOWE
AVIATION...VANDENBOOGART
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