013
FXUS65 KRIW 210736
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1236 AM MST FRI FEB 21 2025
KEY MESSAGES
- WARMING AND DRY TREND FRIDAY AND SATURDAY.
- POSSIBLE ICE JAMMING AND FLOODING DUE TO WARMING TEMPERATURES
SUNDAY THROUGH TUESDAY ACROSS THE BIGHORN BASIN AND JOHNSON
COUNTY.
- NEXT DISTURBANCE WILL PUSH IN SUNDAY THROUGH MID WEEK WITH
POTENTIAL FOR ADVISORY LEVEL SNOW ACROSS WESTERN MOUNTAINS.
DISCUSSION
ISSUED AT 1230 AM MST FRI FEB 21 2025
IR CURRENTLY DEPICTS CLEARING SKIES ACROSS MUCH OF THE STATE AS
UPPER LEVEL RIDGING BUILDS IN FROM THE WEST. SOME COOLER CLOUD
TOPS ACROSS FAR SOUTHERN REACHES OF THE CWA ALONG THE COLORADO
STATE LINE WITH SOME LIGHT LINGERING SNOW FLURRIES PUSHING OUT.
THE MAIN FINGER OF THE PFJ CONTINUES TO STAY TO THE NORTHEAST
DIVING INTO THE GREAT PLAINS KEEPING THE COLDER TEMPERATURES
AWAY. THE WEAK DISTORTION OF THE JET DIVING SOUTH OF THE CWA
HAS SUPPORTED THIS PREVIOUS DISTURBANCE THAT NOW WILL PUSH TO
THE SOUTHEAST GIVING WAY TO TRANQUIL WEATHER CONDITIONS FOR
FRIDAY AND INTO THE WEEKEND. INCREASING UPPER LEVEL CONVERGENCE
WILL ALLOW FOR HIGHER PRESSURE AT THE SURFACE AND WARMING
TEMPERATURES EVEN INTO EARLY NEXT WEEK. AS A RESULT, THE MAIN
CONCERN WILL BE FOR ICE JAMMING AND FLOODING FOR AREA IN
NORTHERN BIGHORN BASIN AND JOHNSON COUNTY DUE TO THE RECENT
SNOWPACK IN LOWER ELEVATIONS. TEMPERATURES EAST OF THE DIVIDE
WILL PUSH INTO THE 40S FRIDAY AND SATURDAY AND 50S TO NEAR 60
SUNDAY THROUGH TUESDAY. WEST OF THE DIVIDE WILL REMAIN IN THE
30S FOR MUCH OF THIS TIME AS THE NEXT DISTURBANCE WILL START TO
AFFECT THESE AREAS COME SUNDAY THROUGH MID WEEK.
THE MAIN PFJ DIPS FURTHER SOUTH ACROSS MONTANA TO NORTHERN
REACHES OF WYOMING BY SUNDAY AFTERNOON GIVING WAY TO THE PACIFIC
NORTHWEST MOISTURE ONCE AGAIN. THIS WILL INCREASE SNOW CHANCES
WEST OF THE DIVIDE, MAINLY FOR THE WESTERN MOUNTAINS THROUGH MID
WEEK. A MIX TO EVEN JUST LIQUID PRECIPITATION POSSIBLE FOR THE
LOWER VALLEYS AS TEMPERATURES COULD REMAIN ABOVE THE FREEZING
MARK FOR MUCH OF THIS PERIOD. TIME WILL TELL, BUT A FORWARD LOOK
ON SNOW ACCUMULATIONS LOOK TO BE MODEST AT BEST TO POSSIBLE
ADVISORY LEVEL CRITERIA FOR THE WESTERN MOUNTAINS TO INCLUDE THE
MAIN PASSES AS PER USUAL WITH THE ZONAL WESTERLY FLOW. THE MAIN
TROUGH LOOKS TO PASS THROUGH THE REST OF THE STATE TO THE EAST
LATE TUESDAY AND INTO EARLY WEDNESDAY THAT WILL GIVE REALLY THE
ONLY CHANCE FOR PRECIPITATION EAST OF THE DIVIDE IN THE LONG
TERM PERIOD. WITH THE WARMER TEMPERATURES ABOVE FREEZING
(ALTHOUGH COOLER TUESDAY AND WEDNESDAY) LIQUID RAIN THE LIKELY
PRECIPITATION FOR THE LOWER ELEVATIONS AND LIKELY SNOW FOR THE
BIGHORNS. OTHERWISE, RIDGING BUILDS BACK IN FOR THE REMAINDER OF
THE WEEK AND INTO THE FOLLOWING WEEKEND WITH DECREASED
DIVERGENCE ALOFT LOOKING TO BE A POSSIBLE OMEGA BLOCK TO END
THE REST OF THE MONTH AND INTO MARCH. WINTER IS STILL NOT DONE,
BUT IT IS IN ITS WANING HOURS IN THE LONGER TERM OUTLOOK.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1033 PM MST THU FEB 20 2025
LIGHT SNOW SHOWERS LINGER ACROSS SOUTHERN WY TO START THE PERIOD BUT
WILL GRADUALLY DISSIPATE WITH LITTLE TO NO IMPACT AT TERMINALS. VFR
CONDITIONS ARE EXPECTED TO PREVAIL THROUGHOUT THE PERIOD WITH THE
ONLY CONCERN BEING A CHANCE FOR PATCHY FOG NEARBY KJAC AND KCPR.
CONFIDENCE IS LOW FOR KCPR WHICH IS WHY NO PREVAILING LOW CLOUDS OR
FOG ARE IN THE TAF. CURRENTLY A LOW/MID LEVEL CLOUD DECK OF BKN030-
060 HANGS ACROSS MOSTLY ALL TERMINALS BESIDES KCPR. FOG CHANCES WILL
LARGELY DEPEND ON HOW QUICKLY CLOUDS CAN CLEAR OUT THROUGH THE
OVERNIGHT INTO FRIDAY MORNING. CLOUDS WILL BE WIDELY SCATTERED FOR
MUCH OF FRIDAY INTO THE END OF THE TAF PERIOD. A LIGHT BREEZE WILL
DEVELOP DURING THE EVENING FRIDAY BRINGING A SLIGHT INCREASE IN
WINDS FOR SOME TERMINALS BUT NOTHING OF CONCERN.
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.
DISCUSSION...LOWE
AVIATION...DZIEWALTOWSKI
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