769
FXUS65 KRIW 051031
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
431 AM MDT TUE MAY 5 2026
KEY MESSAGES
- SCATTERED SHOWER ACTIVITY CONTINUE INTO EARLY TUESDAY MORNING
WITH SOME MIX TO CHANGING OVER TO SNOW POSSIBLE (20-30%).
- SHOWERS BECOME MORE WIDESPREAD INTO TUESDAY AFTERNOON WITH A
FULL CHANGEOVER TO SNOW OVERNIGHT INTO WEDNESDAY MORNING AS
TEMPERATURES WILL BE 10 TO 20 DEGREES COOLER THAN AVERAGE.
- WINTER WEATHER ADVISORIES HAVE BEEN ADDED FOR THE GREEN
MOUNTAINS TO EASTERN SWEETWATER COUNTY DUE TO LIGHT
ACCUMULATING SNOW AND GUSTY WINDS UP TO 30 TO 35 MPH.
- FREEZE WATCHES HAVE BEEN UPGRADED TO FREEZE WARNINGS FOR LOWER
ELEVATIONS EAST OF THE DIVIDE FOR WEDNESDAY MORNING.
- DRY AND WARMING TREND INTO THE WEEKEND AND NEXT WEEK.
DISCUSSION
ISSUED AT 200 AM MDT TUE MAY 5 2026
INCREASING CLOUD COVER PUSHING IN FROM THE NORTH AS DEPICTED ON
IR. L/W TROUGH EXTENDS WITH A POSITIVE TILT NORTHEAST TO
SOUTHWEST TO THE UPPER LEVEL LOW ACROSS THE SIERRA NEVADAS. THIS
HAS GIVEN WAY TO INCREASING DIVERGENCE ALOFT THROUGH NORTHERN
UTAH TO SOUTHERN WYOMING AS THE LOW DEEPENS WITH MODELS HAVING
IT EMBEDDED INTO L/W PATTERN. THE PFJ BECOMES CONTORTED ACROSS
THIS AREA WITH MUCH OF THE PVA ANOMALY EXTENDING ACROSS
SOUTHERN PORTIONS OF THE CWA AND POINTS EAST INTO THE HIGH
PLAINS. AS SUCH, WINTER WEATHER ADVISORIES HAVE BEEN ADDED
ACROSS THE GREEN MOUNTAINS AND EASTERN SWEETWATER COUNTY FOR
LATER TUESDAY EVENING INTO WEDNESDAY MORNING AS THIS TROUGH
PUSHES NORTHEAST. WINDS WILL BE THE MAIN DRIVER WITH THIS AREA
SEEING GUSTS UP TO 30 TO 35 MPH LIKELY CREATING A CROSSWIND
ACROSS I-80 AND HIGHWAY 287 THROUGH JEFFREY CITY TO MUDDY GAP.
LIKELY SNOW AMOUNTS WON'T BE MUCH BUT EXPECTING AROUND 2 TO 3
INCHES (60-70% CONFIDENCE) INDICATIVE OF SOME BLOWING SNOW TO
HINDER VISIBILITY IN THESE AREAS.
OTHERWISE, ONGOING SHOWER ACTIVITY THROUGH SOUTHERN BIGHORN
BASIN INTO EASTERN PORTIONS OF FREMONT COUNTY. MODELS HAVE
PUSHED BACK THE ONSET OF MORE WIDESPREAD, BUT CAMS ARE NOT
HANDLING THIS VERY GOOD AND THUS, SHOWING POPS TO QPF BEING WELL
OVERDONE WITH THE NBM RUNS. WHAT PRECIPITATION IS GOING
CURRENTLY LOOKS TO MIX IN WITH A BIT OF SNOW TO CHANGING OVER
THROUGH SUNRISE TUESDAY MORNING BUT NOT EXPECTING AN
ACCUMULATION AT THIS POINT IN TIME TO HINDER MORNING COMMUTES
WITH TEMPERATURES STILL ABOVE THE FREEZING MARK. WITH AMPLE
CLOUD COVER THROUGHOUT THE DAY AND REINFORCEMENT OF COOLER AIR,
EXPECT TEMPERATURES TO SHOW NOT MUCH OF AN AFTERNOON WARMUP
STRUGGLING TO BREAK THE 40 DEGREE MARK FOR MANY BASINS EAST OF
THE DIVIDE.
BETTER CHANCES FOR PRECIPITATION CHANGING OVER TO SNOW TUESDAY
EVENING AFTER SUNSET AND OVERNIGHT AS THE AFOREMENTIONED UPPER
LEVEL LOW BECOMES PROGRESSIVE AS IT PASSES TO THE SOUTH. THIS
MODEL SHIFT AS PULLED BACK SOME QPF AMOUNTS AS THE MORE AMPLE
ACCUMULATIONS WILL BE EASTWARD AND INTO COLORADO EXTENDING TO
THE HIGH PLAINS REACHING AS FAR AS WESTERN PORTIONS OF NEBRASKA
AND KANSAS. LINGERING PRECIPITATION INTO LATER PARTS OF
WEDNESDAY BUT MOST ACTIVITY WILL END AS THE UPPER TROUGH PUSHES
EAST AND LIFTS OUT OF THE STATE. WEDNESDAY MORNING WILL BE THE
COLDEST OF THE WEEK, WITH FREEZE WARNINGS UPGRADED FOR MANY
LOWER ELEVATIONS EAST OF THE DIVIDE.
BEYOND WEDNESDAY, EXPECT UPPER LEVEL RIDGING TO BUILD IN FROM
THE WEST WITH INCREASING CONVERGENCE ALOFT. THIS WILL PUSH THE
MAIN FINGER OF THE PFJ TO PUSH NORTHEAST FOR THE DAKOTAS AND
INTO THE GREAT LAKE/MISSOURI RIVER BASIN AREAS OF THE COUNTRY.
MODELS HAVE BACKED OFF ON THIS EXTENDING A BIT SOUTHWEST FOR
NORTHEASTERN PORTIONS OF THE CWA FOR SATURDAY, LOOKING TO
REMAIN AT BEST, FAR NORTHEASTERN PARTS OF THE STATE ITSELF.
RIDGING AND NORTHWEST FLOW DOMINATES THE WEATHER PATTERN FOR THE
WEEKEND AND BEYOND INTO NEXT WEEK WITH DRY CONDITIONS AND A
WARMING TREND IN STORE GOING FORWARD.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 430 AM MDT TUE MAY 5 2026
WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS TERMINALS
SHOWERS IN THE VICINITY AT ALL TAF SITES WITH LOW BUT VFR
CEILINGS TO START THE PERIOD. THE NEXT ROUND OF SHOWER ACTIVITY
NOT UNTIL AFTER 00Z WHERE PRECIPITATION TYPE WILL BE SNOW AT
THAT POINT WITH THE COLDER TEMPERATURES. PROB30 GROUPS AT ALL
TAF SITES, LINGERING AT RKS A BIT LONGER WITH MORE ACTIVITY
FURTHER SOUTH. OTHERWISE, GUSTY WINDS WITH RKS THE HIGHEST UP TO
30KTS AFTER 00Z LIMITING VISIBILITY FURTHER DOWN TO IFR WITH
LIGHT SNOW THROUGH ABOUT 06Z. ANY LINGERING SNOW WILL BE
DIMINISHING AND PUSHED EAST AFTER THIS POINT WITH MVFR CEILINGS
LINGERING THROUGH THE END OF THE PERIOD. CONDITIONS WILL LIFT TO
VFR INTO THE NEXT TAF CYCLE LATER WEDNESDAY MORNING AND
AFTERNOON. MOUNTAIN OBSCURATION LIMITED TO START THE PERIOD
WITH MORE PERIODS OVERNIGHT INTO EARLY WEDNESDAY MORNING.
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL TERMINALS
MVFR CONDITIONS AT CPR/RIW/LND WITH LIGHT RAIN LINGERING TO
START THE PERIOD BUT WILL IMPROVE AFTER 14Z. A BREAK UNTIL THE
NEXT ROUND OF PRECIPITATION UNTIL AFTER 21-22Z, WHERE LIGHT
SNOW WILL BE THE PRECIPITATION TYPE DUE TO THE COLDER
TEMPERATURES PUSHING IN FROM THE NORTH. THIS WILL BRING MAINLY
MVFR CONDITIONS RIW/LND/CPR WITH LIGHT SNOW THROUGH ABOUT 06-08Z
WITH LESS CHANCES FURTHER NORTH FOR COD/WRL CARRYING ONLY VCSH
AT THIS TIME. OTHERWISE, SLIGHT BREEZES UP TO 18-20KTS AT MOST
LOCATIONS WITH IMPROVING CONDITIONS THROUGH THE END OF THE
PERIOD ALTHOUGH STILL MVFR. CONDITIONS IMPROVE FURTHER AND LIFT
TO VFR INTO THE NEXT TAF CYCLE LATER WEDNESDAY MORNING AND
AFTERNOON. MOUNTAIN OBSCURATION LIKELY THIS MORNING AND AGAIN
THIS EVENING AND THROUGH THE OVERNIGHT HOURS.
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
FREEZE WARNING FROM 1 AM TO 9 AM MDT WEDNESDAY FOR WYZ003>006-
010-011-017-018-020.
WINTER WEATHER ADVISORY UNTIL 1 AM MDT WEDNESDAY FOR WYZ009-
015.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM MDT
WEDNESDAY FOR WYZ019-030.
DISCUSSION...LOWE
AVIATION...LOWE
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