870
FXUS65 KRIW 200000
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
500 PM MST MON JAN 19 2026
KEY MESSAGES
- A WEAK DISTURBANCE ARRIVES TUESDAY MORNING. THIS WILL BRING
VERY LIGHT SNOW TO NORTHERN WYOMING, AS WELL AS WIND GUSTS OF
30 TO 50 MPH FOR MUCH OF THE AREA.
- ABOVE AVERAGE TEMPERATURES AND MOSTLY DRY CONDITIONS ARE EXPECTED
ACROSS THE AREA THROUGH MOST OF THE WEEK.
- THE NEXT WEAK SYSTEM IS SET TO ARRIVE FRIDAY BRINGING COLDER
TEMPERATURES AND THE POTENTIAL FOR LIGHT MOUNTAIN SNOW.
UPDATE
ISSUED AT 1229 PM MST MON JAN 19 2026
THE FORECAST IS ON TRACK TODAY AS THE WEATHER PATTERN REMAINS
LARGELY UNCHANGED. AFTER A MILD DAY WITH CALMER WIND, THE NEXT WEAK
WAVE WITHIN THE NORTHWESTERLY FLOW ARRIVES TOMORROW MORNING. AS
NOTED BELOW, THIS ONE HAS A LITTLE MORE MOISTURE AND CONSEQUENTLY
THE POTENTIAL FOR LIGHT SNOW (AN INCH OR TWO ON THE HIGH END),
MAINLY ACROSS THE ABSAROKAS AND BIGHORNS. LIGHT FLURRIES ARE ALSO
POSSIBLE (20-30%) ACROSS LOWER ELEVATIONS OF NORTHERN WYOMING DURING
THE DAYLIGHT HOURS TUESDAY, THOUGH AGAIN ACCUMULATIONS ARE EXPECTED
TO BE VERY LIGHT, GENERALLY UNDER HALF AN INCH. WIND WILL BE THE
MORE NOTABLE IMPACT TOMORROW, WITH THE STRONGEST GUSTS 50 TO 60 MPH
IN NORTHERN JOHNSON COUNTY.
DISCUSSION
ISSUED AT 206 AM MST MON JAN 19 2026
THE H5 RIDGE HOLDS IN PLACE YET ANOTHER DAY, DEFLECTING LARGER
WEATHER SYSTEMS AND MOST MOISTURE WELL AWAY FROM THE REGION.
YESTERDAY'S SHORTWAVE WAS ENOUGH TO BRING A FEW NUISANCE
FLURRIES TO CENTRAL WY, BUT NOT MUCH TO SPEAK OF OTHERWISE.
TODAY WILL SEE DECREASING CLOUD COVER AS THE WAVE DEPARTS.
WESTERLY WINDS WILL START RAMPING UPWARDS AGAIN FOR HIGHER
ELEVATIONS AND ACROSS CENTRAL WY DUE TO THE APPROACH OF THE NEXT
WAVE. WINDS WILL HELP KEEP TEMPERATURES MILD AGAIN, WITH HIGHS
AROUND 40 EAST OF THE DIVIDE AND ACROSS SWEETWATER COUNTY, WHILE
WESTERN VALLEYS HOLD AROUND 30 AGAIN.
THE NEXT WAVE ON TUESDAY WILL BRING ANOTHER SURGE OF NORTH
WINDS, BUT IS NOT BRINGING ANY APPRECIABLE COLD WEATHER ALONG
WITH IT, WHICH WILL HOLD BACK INTO LATER IN THE AFTERNOON.
TEMPERATURES MOST OF THE DAY WILL AGAIN RISE INTO THE 30S AND
40S. THERE IS ENOUGH MOISTURE TO BRING SNOW INTO THE HIGHER
ELEVATIONS OF THE BIGHORNS, BUT WRINGING OUT MORE THAN 1 TO 2
INCHES WILL BE TOUGH. SOME LIGHT PRECIP MAY DRIFT INTO THE
LOWER ELEVATIONS EAST OF THE DIVIDE, BUT WITH MILD TEMPS, EXPECT
ONLY LIGHT DRIZZLE/FLURRIES AT BEST. NORTH WINDS WITH THIS WAVE
WILL JUMP AGAIN EAST OF THE DIVIDE, WITH GUSTS 30 TO 30 FOR THE
BIGHORN AND WIND RIVER BASINS, AND ANOTHER 50 TO 60 MPH EVENT
ACROSS JOHNSON COUNTY. A TRAILING WAVE SWEEPS SOUTHWARD ACROSS
THE DAKOTAS ON WEDNESDAY. THIS IS TOO FAR EAST TO PROVIDE ANY
PRECIP, BUT WILL REINFORCE THE GUSTY NORTH WINDS, ESPECIALLY
ACROSS JOHNSON COUNTY.
THURSDAY LOOKS TO BE A MILD DAY AGAIN, AS THE RIDGE AXIS SHIFTS
EASTWARD ALONG THE ROCKIES FOR THE DAY. FOR THE UPCOMING
WEEKEND, CONFIDENCE REMAINS LOWER, AS MODELS CONTINUE TO VARY ON
COLD AIR AND PRECIP WITH THE NEXT SYSTEM. THERE IS A
CONSIDERABLE COLD POOL RACING SOUTHWARD INTO THE CENTRAL US, BUT
HOW MUCH OF THE COLD AIR GETS INTO WYOMING IS THE DIFFICULT PART
OF THE FORECAST. WILL KEEP A CLOSE EYE ON THESE.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 455 PM MST MON JAN 19 2026
VFR CONDITIONS PREVAIL ACROSS WESTERN AND CENTRAL WYOMING OVER
THE NEXT 24 HOURS. THE MOST IMPACTFUL WEATHER TO MOST AVIATION
INTERESTS WILL BE THE STRONG NORTHWESTERLY WINDS THAT DEVELOP
TONIGHT AT MANY LOCATIONS. THESE WINDS EVENTUALLY AFFECT MOST
OF THE REGION BY TUESDAY AFTERNOON AS A COLD FRONT PUSHES
SOUTHWARD ACROSS THE STATE. THOSE IN FAR WESTERN WYOMING VALLEYS
WILL BE SPARED THE STRONGER WINDS, BUT BASIN LOCATIONS IN
CENTRAL WYOMING ARE LIKELY TO SEE GUSTS IN THE 25 TO 35 KT
RANGE BY TUESDAY AFTERNOON.
IN PATTERNS LIKE THIS, KBYG (BUFFALO, WY) OFTEN SEES STRONGER
NORTHERLY GUSTS IN THE 40 TO 50 KT RANGE. THE FRONT IS EXPECTED
TO START IMPACTING KBYG AROUND 20/1700Z, AND A FEW SNOW SHOWERS
COULD ACCOMPANY THE FRONT FOR A FEW HOURS AFTER THIS, BOTH HERE
AND FOR LOCATIONS NORTHWARD TOWARD SHERIDAN, WY. MINIMAL
ACCUMULATIONS ARE EXPECTED.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...MYERS
DISCUSSION...STRAUB
AVIATION...VANDENBOOGART
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