136
FXUS65 KRIW 080318
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
ISSUED BY NATIONAL WEATHER SERVICE BILLINGS MT
918 PM MDT WED MAY 7 2025
KEY MESSAGES
- ISOLATED SHOWERS POSSIBLE THURSDAY AFTERNOON ACROSS THE
NORTHWEST MOUNTAINS.
- WEEKEND HIGH TEMPERATURES RISE 10 TO 20 DEGREES ABOVE NORMAL
WITH NEAR-RECORD HIGH TEMPERATURES POSSIBLE.
UPDATE
ISSUED AT 104 PM MDT WED MAY 7 2025
SATELLITE IMAGERY SHOWS CLOUDS CONTINUING TO GRADUALLY CLEAR
ACROSS THE STATE. SUNSHINE WILL ATTEMPT TO BREAK THROUGH ANY
LINGERING CLOUD COVER TODAY LEADING TO A MUCH WELCOMED WARMING
OF TEMPERATURES. AFTER HIGHS ONLY IN THE LOW TO MID 40S
YESTERDAY, TODAYS VALUES WILL RETURN TO MORE SEASONABLE RANGES.
THE CURRENT FORECASTED HIGHS FOR TODAY RANGE IN THE LOW TO
UPPER 60S.
WARM AND MAINLY DRY PATTERN CONTINUES THROUGH THE REMAINDER OF
THE WEEK. THE ONLY EXCEPTION WILL BE MAINLY ACROSS NORTHERN AND
WESTERN PARTS OF THE STATE WHERE CHANCES FOR ISOLATED SHOWERS
DEVELOP DUE TO A PASSING WEAK SHORTWAVE. TEMPERATURES CONTINUE
TO WARM THROUGH THE END OF THE WEEK WITH HIGHS CLIMBING INTO THE
LOW TO UPPER 70S. THESE WARM TEMPERATURES LOOK TO BE THE MAIN
CONCERN AS WE HEAD INTO A STRETCH OF MOSTLY QUIET WEATHER.
ABOVE NORMAL TEMPERATURES PERSIST ACROSS THE REGION INTO THE
WEEKEND WITH EVEN WARMER TEMPERATURES FORECAST FOR SATURDAY
THROUGH MONDAY. CURRENT MODEL GUIDANCE IS SUGGESTING HIGHS
POSSIBLE 10 TO 20 DEGREES ABOVE NORMAL. TEMPERATURES MAY REACH
THE UPPER 70S WEST OF THE DIVIDE AND LOW TO MID 80S EAST OF THE
DIVIDE. THE WARMEST TEMPERATURES MAY BE ACROSS THE BIGHORN BASIN
WHERE HIGHS MAY NEAR 90 DEGREES. IF THIS WERE TO OCCUR, MANY
LOCATIONS MAY SEE NEAR RECORD BREAKING VALUES. THE OTHER CONCERN
WILL BE THE POSSIBILITY FOR SNOW MELT IN LOCATIONS WHERE HIGH
ELEVATIONS HAVE SEEN SNOW PACKS PRIME. THIS SITUATION WILL
CONTINUE TO BE MONITORED AS THERE IS A POSSIBILITY FOR SOME
HYDRO HAZARDS BEING ISSUED TO HIGHLIGHT THESE CONCERNS. AS OF
WEDNESDAY, THE SALT RIVER AND WYOMING RANGES AND ANY CONNECTING
TRIBUTARIES MAY NEED TO BE TO MONITORED.
DISCUSSION
ISSUED AT 302 AM MDT WED MAY 7 2025
AFTER THE WINTRY WEATHER OF THE PAST COUPLE OF DAYS, SPRING
WILL CONTINUE IT'S SWING OF THE PENDULUM, THIS TIME INTO SPRING
AND POSSIBLY A BIT OF SUMMER. THINGS ARE LARGELY QUIET RIGHT
NOW, WITH RADAR ONLY SHOWING A FEW SPRINKLES IN NATRONA COUNTY.
WE STILL HAVE CLOUD COVER HANGING AROUND THE AREA, ALTHOUGH THIS
WILL SLOWLY PART FOR INCREASING AMOUNTS OF SUNSHINE AS THE
UPPER LEVEL LOW OVER THE CENTRAL PLAINS STATES MOVES AWAY. SO,
TODAY LOOKS LIKE A SEASONABLE DAY FOR THE AREA. THERE IS JUST
ENOUGH MOISTURE AND INSTABILITY AROUND FOR A FEW SHOWERS IN THE
AREA, BUT MOST LOCATIONS WILL NOT SEE ONE.
THINGS WILL TURN A BIT MORE ACTIVE FOR THURSDAY AND FRIDAY. A
SHORTWAVE WILL TRACK ACROSS THE AREA ON THURSDAY AND BRING SOME
SCATTERED SHOWERS AND THUNDERSTORMS, WITH AN EMPHASIS ON
NORTHERN AND WESTERN PORTIONS OF THE AREA WHICH WILL HAVE BETTER
FORCING. EVEN HERE, THE CHANCE OF ANY LOCATION SEEING ONE IS
ONLY AROUND 1 OUT OF 3 AND MOST OF THE DAY WILL REMAIN DRY. THE
BIG CHANGE WILL BE TEMPERATURES AS FLOW TURNS TO SOUTHWEST AND
PUSHES TEMPERATURES TO ABOVE NORMAL LEVELS, AVERAGING ABOUT 10
DEGREES ABOVE NORMAL WITH A DECENT CHANCE OF HIGHS IN THE 80S IN
THE NORMALLY WARMER LOCATIONS. ANOTHER SHORTWAVE MOVES IN FOR
FRIDAY WITH ANOTHER CHANCE OF SHOWERS AND STORMS. ON THIS DAY,
MOST MODELS AGREE WITH THE BEST COVERAGE ACROSS EASTERN PORTIONS
OF THE AREA WITH TAPERING CHANCES FURTHER WEST. TEMPERATURES
SHOULD BE SIMILAR TO THURSDAY.
SATURDAY LOOKS LIKE A DRY AND WARM DAY AT THIS POINT. A
APPROACHING TROUGH FOR SUNDAY WILL BRING THE CHANCE OF SHOWERS
AND THUNDERSTORMS, SO THE WEEKEND LOOKS LIKE A 50 - 50 TYPE.
TEMPERATURES THIS WEEKEND WILL LIKELY BE THE HIGHEST SO FAR THIS
CALENDAR YEAR. SOME OF THE WARMER LOCATIONS, LIKE WORLAND AND
GREYBULL, COULD MAKE A RUN AT 90 DEGREES FOR A HIGH, ESPECIALLY
ON SUNDAY, WHEN INCREASING WIND AHEAD OF THE TROUGH MAY ENHANCE
MIXING. IF IT HAPPENS AT GREYBULL, IT COULD TIE THE EARLIEST 90
DEGREE HIGH IN STATION HISTORY.
EARLY NEXT WEEK, A LOT DEPENDS ON WHAT HAPPENS WITH AN UPPER
LEVEL LOW THAT WILL BE MOVING ONSHORE IN THE PACIFIC NORTHWEST.
THERE IS A LACK OF AGREEMENT IN REGARDS TO THE PROGRESSION OF
THIS SYSTEM. IT HAS THE POTENTIAL TO BRING A DECENT RAIN OR EVEN
STRONG THUNDERSTORMS DEPENDING ON THE SCENARIO. MY GUT FEELING
IS THAT IT WILL BE SLOWER, SINCE THE MODELS USUALLY HAVE A FAST
BIAS THIS FAR OUT. HOWEVER, DETAILS ON TIMING AND PLACEMENT OF
PRECIPITATION ARE ANYONES GUESS AT THIS POINT.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 441 PM MDT WED MAY 7 2025
ALL SITES WILL PREVAIL VFR THROUGH THE PERIOD WITH MOSTLY CLEAR
SKIES AS HIGH PRESSURE BUILDS ACROSS THE REGION. LIGHT WINDS,
LESS THAN 12 KT, ALSO GENERALLY PREVAIL THROUGH THE PERIOD,
ALTHOUGH A FEW SITES MAY START TO SEE GUSTS TO AROUND 15 TO
20 KT THURSDAY AFTERNOON. ALSO THURSDAY AFTERNOON, KCOD WILL
SEE CLOUDS INCREASE IN COVERAGE AS THERE MAY BE SOME WEAK
OROGRAPHIC SHOWER AND THUNDERSTORM ACTIVITY. NO SHOWERS OR
THUNDERSTORMS ARE EXPECTED TO IMPACT THE KCOD TERMINAL (LESS
THAN 10% CHANCE OF IMPACTS).
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...LAVOIE/HENSLEY
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