224
FXUS65 KRIW 211120
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
420 AM MST WED JAN 21 2026
KEY MESSAGES
- STRONG WIND LIKELY IN JOHNSON COUNTY THIS MORNING, OTHERWISE
MAINLY DRY WITH TEMPERATURES CLOSE TO NORMAL FOR MOST.
- A COLD FRONT WILL BRING SOME OF THE COLDEST TEMPERATURES IN
QUITE A WHILE FOR MANY LOCATIONS FRIDAY INTO THE WEEKEND.
- THERE WILL BE A FEW CHANCES FOR MAINLY LIGHT SNOW, BUT NO
MAJOR STORMS ARE EXPECTED THROUGH THE WEEKEND.
DISCUSSION
ISSUED AT 158 AM MST WED JAN 21 2026
IT HAS BEEN A VERY MILD WINTER ACROSS MOST OF THE AREA SO FAR THIS
YEAR. IT HAS TURNED MORE SEASONABLE LATELY, BUT WE HAVE BEEN LACKING
SOME REALLY COLD TEMPERATURES. MANY LOCATIONS CONTINUE TO AVERAGE
MORE THAN 10 DEGREES ABOVE NORMAL THROUGH METEOROLOGICAL WINTER
(DECEMBER THROUGH FEBRUARY). AND LOCALLY, HERE AT THE HUMBLE
RIVERTON WEATHER ABODE AND IN NEARBY LANDER, I WAS LOOKING AT BELOW
ZERO LOWS, OR THE LACK OF THIS YEAR. AT THE AIRPORT, WE HAVE NOT
DONE IT ONCE SO FAR THIS WINTER. THIS CURRENTLY THE SECOND LATEST
(2000 WAS JANUARY 29TH) AND LANDER, WHICH HAS RECORDS THAT DATE BACK
TO 1891, IT IS THE THIRD LATEST (FEBRUARY 25 IN 1934 IS THE LATEST).
WE MAY FINALLY HAVE A CHANCE TO REACH THAT MARK, BUT IN A FEW DAYS.
TODAY LOOKS TO BE A SEASONABLE AND MAINLY DRY DAY. WE CAN'T
COMPLETELY RULE OUT A STRAY SNOW SHOWER OVER THE BIGHORNS, BUT THE
CHANCE IS SO LOW (LESS THAN 1 OUT OF 10) WE HAVE LEFT IT OUT OF THE
FORECAST. THIS WILL BE COURTESY OF ANOTHER COLD FRONT DROPPING
SOUTHWARD THROUGH THE AREA, AND HAS EVEN LESS MOISTURE THEN THE ONE
YESTERDAY. THE MAIN IMPACT WILL BE MORE GUSTY WIND, MAINLY OVER
JOHNSON COUNTY, AS IS USUAL WITH COLD ADVECTION / NORTHWEST FLOW
SITUATIONS. I HAVE A SMALL CONCERN FOR A FEW HIGH WIND GUSTS, AS THE
NBA ENSEMBLE GUIDANCE HAS A 1 IN 2 CHANCE OF WIND GUSTS OF 50 MPH
AND THERE IS SOME RIGHT FRONT JET DYNAMICS FOR A BIT OF DOWNWARD
FORCING. THE STRONGEST WIND WOULD ONLY LAST AROUND 6 HOURS. THIS IS
A BIT SIMILAR TO YESTERDAY EXCEPT NO SNOW, WHEN THE HIGH WIND GUSTS
WERE ISOLATED. SO, NO WIND HIGHLIGHTS ALTHOUGH WE MAY ISSUE A
SPECIAL WEATHER STATEMENT. GUSTY BREEZES MAY BE FOUND
ELSEWHERE BUT NO HIGH WIND.
THURSDAY LOOKS TO BE A DAY OF NEAR TO BELOW NORMAL TEMPERATURES,
WITH BREEZES THAT WILL MAKE IT THE COOLEST DAY IN A WHILE. IT LOOKS
MAINLY DRY DURING THE DAY, BUT THE QUESTION IS WHAT WILL HAPPEN WHEN
THE THIRD COLD FRONT THIS WEEK APPROACHES AND MOVES THROUGH THE
AREA. THIS ONE HAS ARCTIC AIR BEHIND IT AND AS A RESULT LITTLE
MOISTURE. HOWEVER, IT DOES HAVE SOME RIGHT REAR QUADRANT ENERGY THAT
MAY ENHANCE UPWARD MOTION SOMEWHAT. THE PROBLEM IS THERE IS LITTLE
MOISTURE TO LIFT. THERE IS A MODEL SPREAD WITH THE DETERMINISTIC
MODELS, WITH THE EUROPEAN THE WETTEST, BUT EVEN IT ONLY GIVES BARELY
OVER A TENTH OF AN INCH OF QPF. AS FOR PROBABILISTIC GUIDANCE, THE
BEST CHANCE OF OVER AN INCH OF SNOW IS AROUND CASPER, WHERE SOME
ANAFRONTAL NORTHERLY FLOW MAY BRING A BRIEF PERIOD OF UPSLOPE, BUT
EVEN HERE IT IS ONLY AROUND 1 OUT OF 3 THROUGH FRIDAY NIGHT. SNOW
SHOWERS WOULD COULD FALL IN AREAS SIMILAR TO TUESDAY. THE SNOW WILL
NOT BE THE MAIN CONCERN THOUGH.
THE MAIN CONCERN WILL BE THE COLD TEMPERATURES, THE COLDEST OF THE
YEAR FOR MANY LOCATIONS. MODELS HAVE TRENDED COLDER THAN YESTERDAY.
AND ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN WELL EAST OF
WYOMING, SOME AREAS WILL SEE 700 MILLIBAR TEMPERATURES AS LOW AS
MINUS 20. THIS IS THE BEST CHANCE OF AREAS LIKE RIVERTON AND LANDER
TO FINALLY FALL TO BELOW ZERO. PROBABILISTIC GUIDANCE GIVES AT LEAST
A 1 IN 2 CHANCE OF LOWS BELOW ZERO ACROSS MOST AREAS EAST OF THE
DIVIDE. THE ONE CONCERN I HAVE IS THAT THE COLD ADVECTION MAY HAVE
TO OVERCOME CLOUD COVER. HOWEVER, FRIDAY NIGHT LOOKS TO BE THE
COLDEST NIGHT IN A WHILE FOR MANY LOCATIONS.
SATURDAY LOOKS DRIER AND A BIT WARMER BEFORE ANOTHER COLD FRONT
MOVES THROUGH SATURDAY NIGHT AND SUNDAY WITH A REINFORCING SHOT OF
COLDER AIR. THIS IS SIMILAR TO THE LAST FEW, WITH MORE WIND
IMPACTS THAN SNOW AS IT, SAY IT WITH ME, MOISTURE STARVED.
FOLLOWING THAT, FLOW TURNS MORE ZONAL AGAIN AND WILL BRING A
RETURN TO NEAR TO SOMEWHAT ABOVE NORMAL TEMPERATURES BY EARLY
NEXT WEEK.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 416 AM MST WED JAN 21 2026
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS, STARTING WITH
CLEAR SKIES BEFORE SOME HIGH CIRRUS SWEEPS IN THIS EVENING.
GUSTY NORTHWEST WINDS CONTINUE TO SWEEP ACROSS CENTRAL WY,
AND WILL CONTINUE TO BRING GUSTS OF 25 TO 30KTS FOR KCPR AND
KBYG, WITH REMAINING SITES STAY BELOW 10KTS.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...HATTINGS
AVIATION...STRAUB
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page