282
FXUS65 KRIW 060346
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
946 PM MDT TUE MAY 5 2026
KEY MESSAGES
- SNOW WILL CONTINUE ACROSS THE WIND RIVER BASIN AND EASTERN
PORTIONS OF SWEETWATER COUNTY FOR THE NEXT FEW HOURS,
GRADUALLY ENDING AFTER MIDNIGHT.
- WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR THE GREEN
MOUNTAINS TO EASTERN SWEETWATER COUNTY DUE TO LIGHT
ACCUMULATING SNOW AND GUSTY WINDS UP TO AROUND 35 MPH.
- FREEZE WARNINGS ARE IN EFFECT FOR LOWER ELEVATIONS EAST OF THE
DIVIDE FOR WEDNESDAY MORNING, AS LOW TEMPERATURES ARE IN THE
20S.
- DRY AND WARMING TREND INTO THE WEEKEND AND NEXT WEEK.
UPDATE
ISSUED AT 1256 PM MDT TUE MAY 5 2026
TODAY'S WEATHER SYSTEM IS MAINLY ON TRACK. ONE POINT OF FOCUS WITH
THIS UPDATE IS SNOW POTENTIAL AROUND THE LANDER AREA. UPPER-LEVEL
DYNAMICS AND FAVORED FLOW HAS THE POTENTIAL TO BRING HEAVIER
PRECIPITATION TO THE LANDER AREA LATE THIS AFTERNOON AND INTO THE
EVENING. SOME HI-RES MODELS ARE DEPICTING SNOW TOTALS UP TO AROUND 8
INCHES, THOUGH THIS SCENARIO SEEMS UNLIKELY (10% CHANCE OR LESS). A
MORE REALISTIC ESTIMATE MAY BE 2 TO 4 INCHES, WHICH WOULD OCCUR IN A
FAIRLY QUICK TIME PERIOD THIS EVENING. ONE ADDITIONAL THING TO NOTE
IS THAT THERE WILL LIKELY BE A STEEP SNOW AMOUNT GRADIENT FROM
LANDER TOWN TO THE MOUNTAINS, SO AMOUNTS MAY QUICKLY CHANGE FROM 1
INCH TOTALS NORTH OF TOWN TO LIKE 6 INCHES TOWARDS SINKS CANYON. THE
MAJORITY OF SNOW SHOULD END BY MIDNIGHT, WITH LIGHT LINGERING SNOW
POSSIBLE THROUGH AROUND SUNRISE. OTHERWISE, HIGHLIGHTS REMAIN, WITH
A COMBINATION OF SNOW AND WIND BRINGING MINOR IMPACTS TO I-80 IN
SWEETWATER COUNTY AND NORTHWARD TO SOUTH PASS AND AROUND JEFFERY
CITY.
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 PRECIPITATION, BUT
CAMS ARE NOT HANDLING THIS VERY WELL AND THUS, SHOWING POPS TO
QPF BEING WELL OVERDONE WITH THE NBM RUNS. WHAT PRECIPITATION IS
ONGOING LOOKS TO MIX IN WITH, OR CHANGE OVER TO, SNOW THROUGH
SUNRISE TUESDAY MORNING BUT NOT EXPECTING ANY 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 HAS 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. PRECIPITATION LINGERS 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, FOR 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 /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 945 PM MDT TUE MAY 5 2026
WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS TERMINALS.
MARGINAL MVFR CONDITIONS WILL REMAIN POSSIBLE AT KBPI/KPNA
THROUGH 10Z, WITH A 30% CHANCE FOR LIGHT SNOW TO IMPACT KPNA AS
A LINE OF SHOWERS MOVE OVER THE SITE. THESE CONDITIONS ARE ALSO
EXPECTED AT KRKS, WITH EAST- NORTHEAST WINDS GUSTING UP TO
30KT. THESE WINDS WILL DECREASE BY 08Z. KJAC IS EXPECTED TO
REMAIN VFR WITH CLEARING SKIES, ALTHOUGH SURROUNDING MOUNTAINS
WILL BE FREQUENTLY OBSCURED. CONDITIONS WILL IMPROVE AFTER
SUNRISE WEDNESDAY AS SKIES CLEAR THROUGH THE REST OF THE
MORNING, WITH LIGHTER WINDS AND SKC SKIES EXPECTED THROUGH THE
AFTERNOON. GUSTS AROUND 20KT WILL OCCUR IN THE AFTERNOON AT
KJAC, KBPI AND KPNA.
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL TERMINALS.
SNOW WILL BE WANING AT KRIW BY THE START OF THE TAF PERIOD, BUT
IS EXPECTED TO CONTINUE AT KLND THROUGH 08Z. THERE IS A 20-30%
FOR IFR/LIFR CONDITIONS TO CONTINUE AT KLND AFTER THE SNOW ENDS.
SKIES WILL BE CLEARING FROM NORTH TO SOUTH, WITH SKC SKIES
EXPECTED AT KCOD BY 09Z. THIS TREND WILL CONTINUE THROUGH THE
REST OF THE MORNING, WITH SKC SKIES EXPECTED ACROSS THE AREA BY
18Z.
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 UNTIL 7 AM MDT WEDNESDAY FOR WYZ019-
030.
UPDATE...WITTMANN
DISCUSSION...LOWE
AVIATION...LAVOIE
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