990
FXUS65 KRIW 061950
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
ISSUED BY NATIONAL WEATHER SERVICE BILLINGS MT
150 PM MDT TUE MAY 6 2025
KEY MESSAGES
- SCATTERED RAIN/SNOW SHOWERS LINGER THROUGH THE AFTERNOON AND
EVENING MAINLY FOR LOCATIONS EAST OF THE DIVIDE.
- SKIES GRADUALLY CLEAR OUT OVERNIGHT WITH MOSTLY DRY CONDITIONS
EXPECTED INTO THE WEEKEND.
- WARM ABOVE NORMAL TEMPERATURES ARE LIKELY TO RETURN TO THE
REGION BY THE END OF THE WEEK WITH THE POSSIBILITY FOR NEAR
RECORD BREAKING HIGH TEMPERATURES BY THE WEEKEND.
UPDATE
ISSUED AT 144 PM MDT TUE MAY 6 2025
MUCH OF THE FORECAST REMAINS UNCHANGED AS WRAP AROUND MOISTURE
CONTINUES TO MOVE INTO PORTIONS OF THE STATE THIS MORNING LEADING TO
PERIODIC SHOWERS. SHOWERY ACTIVITY WILL LINER INTO THE AFTERNOON AND
EVENING BEFORE DISSIPATING OVERNIGHT. TEMPERATURES ARE FORECAST TO
GRADUALLY WARM THROUGHOUT THE DAY AND WILL LIKELY BE WARM
ENOUGH FOR MANY LOCATIONS TO SEE A TRANSITION BACK OVER TO RAIN.
OVERALL, FORECASTED HIGHS FOR TODAY WILL BE WELL BELOW NORMAL
WITH THE COLDEST VALUES EAST OF THE DIVIDE, WITH TEMPERATURES
IN THE UPPER 30S TO MID 40S. WEST OF THE DIVIDE WILL SEE WARMING
TEMPERATURES IN THE LOW 50S AS CLOUD COVER SCATTERS LEADING TO
BRIEF PERIODS OF SUNSHINE. GUSTY WINDS CONTINUE ACROSS SOUTHERN
WY WITH GUSTS OF 35 TO 45 KNOTS AT TIMES THIS AFTERNOON BEFORE
GRADUALLY WEAKENING BY THE LATE EVENING HOURS.
THE REMAINDER OF THE WEEK CONTINUES TO LOOK MOSTLY QUIET WITH
RIDGING BUILDING IN OVER THE REGION. THERE REMAINS THE POSSIBILITY
OF SOME ISOLATED SHOWERS OVER THE NEXT FEW DAYS BUT MOST WILL REMAIN
DRY. WARMER TEMPERATURES ARE EXPECTED TO BUILD IN WITH HIGHS LIKELY
BECOMING WELL ABOVE NORMAL BY THE END OF THE WEEK. MODEL GUIDANCE IS
STARTING TO HINT AT SOME LOCATIONS MAINLY EAST OF THE DIVIDE
REACHING THE MID 80S AND POSSIBLY UPPER 80S. THERE IS STILL TIME FOR
THINGS TO CHANGE BUT JUST HOW WARM IT GETS WILL NEED TO BE MONITORED
AS THIS MAY LEAD TO SOME RAPID SNOWMELT IN THE MOUNTAINS.
DISCUSSION
ISSUED AT 208 AM MDT TUE MAY 6 2025
WHEN I WAS GROWING UP BACK IN THE TIMES WHEN DINOSAURS ROAMED THE
EARTH (THE 70S AND 80S FOR REFERENCE), I OFTEN ENTERTAINED MYSELF
AFTER SCHOOL BY WATCHING RE-RUNS OF OLD SITCOMS. AND ONE MY
FAVORITES WAS THE SECRET AGENT PARODY GET SMART. AND ONE DON ADAMS'
(THE STAR OF THE SHOW) CATCH PHRASES WAS "MISSED IT BY THAT MUCH",
IMPLYING A CLOSE MISS.
IN REGARDS TO THIS MORNING, IT WAS THE SNOW. THE COLD CAME IN A
LITTLE FASTER AND DEEPER THAN I THOUGHT YESTERDAY MORNING. THE
RESULT IS BIGGER SNOW ACCUMULATIONS THEN I THOUGHT. LANDER WAS
ALREADY UP TO 2 INCHES AT MIDNIGHT, AND WE HAVE SOME ACCUMULATION AT
THE OFFICE AS WELL. MOST ROADS BELOW AROUND 5800 FEET ARE MAINLY WET
THOUGH, INCLUDING AT OUR OFFICE WHERE THE PARKING LOT HAS REMAINED
JUST WET. WE DO HAVE SOME SLICK ROADS ABOVE THIS THOUGH, WITH THE
WORST CONDITIONS OVER SOUTH PASS. SNOW WILL CONTINUE THROUGH THE
NIGHT. HOWEVER, WE CAN SEE THE LIGHT AT THE END OF THE TUNNEL. ALL
GUIDANCE SHOWS THE HEAVIEST PRECIPITATION ENDING AROUND SUNRISE. IN
ADDITION, THE STRONG MAY SUN WILL HAVE AN IMPACT, MELTING THE SNOW
OFF MOST ROADS BY MID MORNING AND THE WARMING TEMPERATURES AND LESS
INTENSE PRECIPITATION RATES WILL SEE A LOT OF SNOW MIX WITH OR
CHANGE BACK TO RAIN IN THE LOWER ELEVATIONS. THE CHANCES OF GREATER
THAN AN ADDITIONAL INCH OF SNOW AFTER 6 AM ARE AT MOST 1 OUT OF 3 IN
THE LOWER ELEVATIONS. THERE WILL STILL BE SOME DIFFICULT CONDITIONS
OVER THE PASSES IN THE MORNING THOUGH, SO WE WILL KEEP THE
ADVISORIES UP FOR NOW. SHOWERS WILL CONTINUE THROUGH THE DAY,
ALTHOUGH COVERAGE WILL DECREASE, ESPECIALLY IN THE AFTERNOON WITH
ALMOST ALL OF THEM OVER BY MIDNIGHT TONIGHT. IT WILL BE ANOTHER
COLD DAY THROUGH, WITH MANY AREAS EAST OF THE DIVIDE STRUGGLING TO
REACH 40 DEGREES. MOST AREAS WILL ALSO SEE THE GUSTY WIND DECREASE
THROUGH THE DAY. THE EXCEPTION WILL BE SOUTHERN WYOMING, ESPECIALLY
SWEETWATER COUNTY WHERE A DECENT PRESSURE GRADIENT WILL REMAIN. MANY
LOCATIONS, ESPECIALLY THE EASTERN HALF OF THE COUNTY, HAVE A GREATER
THAN 1 IN 2 CHANCE OF WIND GUSTS PAST 40 MPH THROUGH THE DAY.
THE REST OF THE FORECAST LOOKS QUIETER, NOT QUIET, BUT QUIETER. A
BIT OF LINGERING MOISTURE AND CYCLONIC CURVATURE COULD KEEP A FEW
SHOWERS OVER THE AREA WEDNESDAY, BUT MOST AREAS WILL REMAIN DRY.
OTHERWISE, IT WILL BE A CLOSE TO NORMAL SPRING DAY WITH TEMPERATURES
NEAR TO SLIGHTLY BELOW NORMAL. FLOW THEN TURNS MORE WEST TO
SOUTHWEST, AND AS A RESULT WE WILL SEE A RETURN TO ABOVE NORMAL
TEMPERATURES ACROSS MOST OF THE AREA FROM THURSDAY THROUGH THE
WEEKEND AS RIDGING BUILDS ACROSS THE ROCKIES. WYOMING WILL BE NEAR
THE TOP OF THE RIDGE THOUGH, AND THIS WILL LEAD TO A COUPLE OF
SHORTWAVES TRACKING ACROSS NORTHERN WYOMING AND BRING A COUPLE OF
CHANCE OF SHOWERS AND THUNDERSTORMS ON THURSDAY AND FRIDAY. AT THIS
POINT THOUGH, NO STRONG STORMS ARE EXPECTED AND MOST LOCATIONS
SHOULD REMAIN DRY ON ANY GIVEN DAY.
THE RIDGE AXIS SHOULD BE OVER THE AREA ON SATURDAY, BRING A WARM AND
DRY DAY TO THE AREA. AFTER THAT THE RIDGE MAY BREAK DOWN AND BRING A
RETURN OF A MORE ACTIVE PATTERN. AT THIS POINT, SUNDAY MAY HAVE SOME
THUNDERSTORMS, MAINLY IN THE WEST. THE MIDDLE OF NEXT WEEK LOOKS
POTENTIALLY INTERESTING WITH AN UPPER LEVEL LOW APPROACHING THE
AREA, BUT DETAILS THIS FAR OUT ARE IMPOSSIBLE TO PREDICT.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1135 AM MDT TUE MAY 6 2025
EAST OF THE DIVIDE TERMINALS (KCOD, KCPR, KLND, KRIW, KWRL)...
MOSTLY MVFR CONDITIONS AT MANY LOCATIONS TO START THE PERIOD,
ESPECIALLY EAST OF THE DIVIDE. PRECIPITATION IS GENERALLY
ENDING, BUT LOW CLOUDS AND MVFR VISBY WILL CONTINUE ALONG WITH
MVFR TO IFR CIGS THROUGH MUCH OF THE PERIOD. TOWARDS SUNSET
AFTER 23-01Z, ANY LINGERING PRECIPITATION SHOULD BE CONSTRAINED
TO THE HIGHER TERRAIN AND DIMINISHED INTO THE LOWER ELEVATIONS
EAST OF THE DIVIDE. VFR WILL BEGIN TO PREVAIL FOR MOST TERMINALS
BY THE END OF THE PERIOD.
WEST OF THE DIVIDE TERMINALS (KBPI, KJAC, KPNA, KRKS)...
VFR AT BPI/PNA/JAC WEST OF THE DIVIDE WITH MUCH OF THE PRECIPITATION
TO THE EAST. KRKS WILL KEEP MVFR AND GUSTY WINDS 20 TO 30 KTS
THROUGH THE FIRST PART OF THE PERIOD, WITH WINDS DECREASING
OVERNIGHT. THERE IS A 20 TO 30% CHANCE OF FOG AROUND SUNRISE AT KBPI
AND KPNA. OTHERWISE, SKIES WILL BECOME MOSTLY CLEAR BY THE END OF
THE PERIOD WITH LIGHT WINDS.
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...DZIEWALTOWSKI
DISCUSSION...HATTINGS
AVIATION...HENSLEY
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