790
FXUS65 KRIW 152324
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
424 PM MST THU JAN 15 2026
KEY MESSAGES
- WARM AND BREEZY CONDITIONS PERSIST ACROSS THE COWBOY STATE
TODAY.
- A NEARING COLD FRONT WILL USHER IN COOLER TEMPERATURES AS
EARLY AS THIS EVENING. WINDS WILL INCREASE WITH THE FRONT WITH
STRONG GUSTY WINDS POSSIBLE ESPECIALLY IN PARTS OF JOHNSON
COUNTY.
- ISOLATED SHOWERS MAY BE POSSIBLE IN ASSOCIATION WITH THE
FRONTAL PASSAGE THIS EVENING THROUGH EARLY FRIDAY MORNING.
- MILD TEMPERATURES AND MAINLY QUIET CONDITIONS RETURN FOR THE
WEEKEND THROUGH THE FIRST HALF OF NEXT WEEK.
UPDATE
ISSUED AT 1158 AM MST THU JAN 15 2026
NOT MUCH HAS CHANGED REGARDING THE SHORT TERM FORECAST WITH THE
PREVIOUS DISCUSSION EXPLAINING THE SETUP WELL. WINDS DO LOOK TO
INCREASE THROUGH THE AFTERNOON AND EVENING TODAY AS THE COLD
FRONT NEARS THE AREA. THE STRONGEST GUSTS REMAIN ACROSS PORTIONS
OF JOHNSON COUNTY, WHERE HIGH WIND WARNINGS ARE IN EFFECT.
CONFIDENCE IS LACKING TO ISSUE ADDITIONAL HIGHLIGHTS FOR PARTS
OF THE BIGHORN BASIN AND NATRONA COUNTY. THAT BEING SAID THERE
STILL MAY BE SOME STRONG GUSTS OF 50 MPH OR MORE AT TIMES IN
THESE LOCATIONS. SOME ISOLATED SHOWERS MAY BE POSSIBLE AS THE
FRONT PASSES THIS EVENING INTO THE EARLY MORNING HOURS FRIDAY.
THE BEST CHANCES 30-60% FOR A BRIEF SHOWER LOOK TO BE ACROSS
PORTIONS OF THE BIGHORN BASIN, JOHNSON, AND NATRONA COUNTIES.
FREMONT COUNTY MAY SEE A VERY ISOLATED SHOWER WITH CHANCES
AROUND 20-40%. PRECIPITATION SHOULD DISSIPATE BY SUNRISE ON
FRIDAY WITH MOST REMAINING DRY THROUGHOUT THE DAY. HIGH
TEMPERATURES FOR FRIDAY HAVE TRENDED COOLER WITH THE CURRENT
FORECAST BEING TEMPERATURES RANGING FROM THE MID 20S TO MID 30S.
THE COLDEST TEMPERATURES LOOK TO BE OVER WESTERN WY AND ACROSS
JOHNSON AND NATRONA COUNTIES.
THE WEEKEND LOOKS TO BE MOSTLY DRY WITH TEMPERATURES REMAINING
MILD BUT COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS. A FEW
ISOLATED SHOWERS CANNOT BE RULED OUT SUNDAY AS A DISTURBANCE
MOVES ACROSS THE CENTRAL CONUS. OTHERWISE MILD AND MOSTLY QUIET
WEATHER PREVAILS THROUGH THE FIRST HALF OF NEXT WEEK. LOOKING
FARTHER TOWARDS THE SECOND HALF OF THE WEEK A POTENTIAL PATTERN
SHIFT REMAINS POSSIBLE. HOWEVER, MODELS HAVE BEGUN TO DEVIATE, LEADING
TO LESSER CONFIDENCE ON JUST HOW LONG THIS BREAK IN THE PATTERN
MAY LAST.
DISCUSSION
ISSUED AT 202 AM MST THU JAN 15 2026
SATELLITE WATER VAPOR IMAGERY AT 09Z SHOWS THREE DISTINCT FEATURES
THAT WILL INFLUENCE THE WEATHER ACROSS WYOMING THROUGH SATURDAY. THE
FIRST IS THE UPPER LEVEL RIDGE CENTERED OVER NORTHERN CALIFORNIA,
KEEPING NORTHWESTERLY FLOW ALOFT. THE SECOND FEATURE IS A WEAK
DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW TRAVERSING OVER SOUTHERN
MONTANA AS OF 09Z. THE THIRD FEATURE IS POTENT SHORTWAVE TROUGH,
WITH LIMITED MOISTURE, OVER EASTERN WASHINGTON. THE WEAK
DISTURBANCE, THE SECOND FEATURE MENTIONED, WILL SHIFT INTO NORTHERN
WYOMING EARLY THIS MORNING THROUGH ROUGHLY 10AM. THIS DISTURBANCE
WILL PROVIDE SUPPORT FOR GUSTY 25 MPH TO 35 MPH WINDS ACROSS
NORTHERN JOHNSON COUNTY AND WIND PRONE HIGH ELEVATIONS. BEHIND THIS
DISTURBANCE, WINDS ALOFT BECOME MORE NORTHERLY AND THE SURFACE
PRESSURE GRADIENT WILL BE TIGHTENING AHEAD OF AN APPROACHING COLD
FRONT. THUS, A WINDY AFTERNOON IS IN STORE FOR MUCH OF THE AREA WITH
WIDESPREAD GUSTS OF 15 MPH TO 25 MPH ACROSS MANY LOW ELEVATION
AREAS. GUSTS OF 30 MPH TO 45 MPH ARE FORECAST ACROSS
NORTH/NORTHWESTERLY WIND PRONE LOCATIONS SUCH AS NORTHERN JOHNSON
COUNTY, THE CODY FOOTHILLS, PORTIONS OF NATRONA COUNTY, AND HIGH
ELEVATIONS.
THE AFOREMENTIONED COLD FRONT AND POTENT SHORTWAVE TROUGH WILL
TRAVERSE, NORTH TO SOUTH, ACROSS THE STATE BETWEEN 3PM AND 11PM
TODAY. ALONG AND BEHIND THE FRONT, WINDS WILL INCREASE EVEN MORE,
ESPECIALLY ACROSS NORTHERN JOHNSON COUNTY, AS A STRONG, NORTHERLY
UPPER LEVEL JET POSITIONS ITSELF OVER THE STATE. THERE IS HIGH
CONFIDENCE (90%) THAT THE STRONGEST WINDS WILL OCCUR OVER JOHNSON
COUNTY LATE THIS EVENING THROUGH AT LEAST FRIDAY EVENING DUE TO A
60KT TO 70KT 700MB WIND MAXIMUM DIRECTLY OVER THIS AREA. FOR JOHNSON
COUNTY, SUSTAINED WINDS OF 25 MPH TO 40 MPH AND GUSTS AROUND 60 MPH
ARE EXPECTED (90%+ CHANCE) FROM 3PM THIS AFTERNOON THROUGH FRIDAY
EVENING. THUS, THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND
WARNING VALID FROM 3PM THURSDAY THROUGH 5PM FRIDAY. ANOTHER AREA OF
INTEREST DURING THIS TIME FRAME IS THE BIGHORN BASIN, GIVEN THE
FAVORABLE NORTHERLY FLOW. NORTHERLY WINDS OF 20 MPH TO 35 MPH, WITH
75% CHANCE OF GUSTS OF 40 MPH, ARE FORECAST BEHIND THE FRONT AND ON
FRIDAY. A GUST OF 50 MPH IS NOT COMPLETELY OUT OF QUESTION (25% TO
30% CHANCE), HOWEVER, ANY GUSTS ABOVE 50 MPH ARE UNLIKELY GIVEN THE
700MB WIND MAXIMUM IS FARTHER EAST. ON FRIDAY, THERE IS AN 80%
CHANCE OF 40 MPH GUSTS ACROSS NATRONA COUNTY. MOST OTHER LOCATIONS
ACROSS THE STATE WILL HAVE A WINDY THURSDAY EVENING WITH AND FOR A
FEW HOURS BEHIND THE FRONT WITH GUSTS BETWEEN 25 MPH AND 35 MPH.
STAR VALLEY AND JACKSON HOLE VALLEY WILL LIKELY (90%+ CHANCE) BE
SPARED OF ANY GUSTS AT ALL BETWEEN NOW AND FRIDAY EVENING.
THE SECOND STORY WITH THE COLD FRONTAL PASSAGE IS THE ACCOMPANYING
COLDER, NEAR SEASON TEMPERATURES. HIGH TEMPERATURES TODAY/THURSDAY
ARE FORECAST TO BE 15 TO 25 DEGREES ABOVE NORMAL, ESPECIALLY EAST OF
THE DIVIDE, WITH HIGHS IN THE UPPER 40S TO 50S. AT SUNSET THIS
EVENING, MEAN 700MB TEMPERATURES ARE FORECAST TO BE ANYWHERE FROM -
1C TO -6C. BY SUNRISE ON FRIDAY, BEHIND THE FRONT, FORECASTED MEAN
700MB TEMPERATURES DROP TO -9C ACROSS SOUTHWEST WYOMING TO NEAR -20C
ACROSS NORTHEASTERN PORTIONS. THIS MEANS TEMPERATURES FRIDAY MORNING
WILL BE IN THE SINGLE DIGITS ACROSS WEST WYOMING AND TEENS TO LOW
20S (FAHRENHEIT) ELSEWHERE. HIGH TEMPERATURES ON FRIDAY ARE FORECAST
TO BE 20 TO 30 DEGREES COLDER COMPARED TO THIS AFTERNOON'S /
THURSDAY'S HIGH TEMPERATURES, ESPECIALLY EAST OF THE DIVIDE.
HOWEVER, FRIDAY'S TEMPERATURES WILL BE MORE REPRESENTATIVE OF
"NORMAL" MID JANUARY HIGHS.
THE THIRD AND FINAL STORY WITH THE COLD FRONT ARE THE LIGHT
PRECIPITATION CHANCES (20% TO 40%) WITH AND BEHIND THE FRONT ACROSS
JOHNSON AND NATRONA COUNTIES, THE BIGHORNS, CASPER MOUNTAIN, AND
OTHER HIGH ELEVATIONS EAST OF THE DIVIDE. PRECIPITATION WILL BEGIN AS
LIGHT RAIN ACROSS NORTHERN JOHNSON COUNTY BEFORE TRANSITIONING TO
LIGHT SNOW. ACCUMULATIONS WILL BE LIGHT AS THIS IS NOT A VERY
SATURATED SYSTEM. THERE IS A 70% CHANCE OF 0.5 INCHES AND A 40%
CHANCE OF 1 INCH ACROSS NORTHERN JOHNSON COUNTY. OTHER LOW ELEVATION
AREAS OF JOHNSON AND NATRONA COUNTIES WILL BE LUCKY TO SEE 0.5
INCHES.
A WINDY NIGHT CAN BE EXPECTED FRIDAY NIGHT INTO SATURDAY WITH THE
UPPER LEVEL JET STILL OVERHEAD. HOWEVER, WE HAVE OPTED TO NOT EXTEND
THE HIGH WIND WARNING INTO FRIDAY NIGHT AT THIS TIME DUE TO
WEAKENING 700 MB WINDS. THERE IS A GOOD CONSENSUS THAT THE WEST
CONUS RIDGE WILL REMAIN IN PLACE FROM SUNDAY THROUGH AT LEAST MID
NEXT WEEK, ULTIMATELY KEEPING MOST OF THE AREA PRECIPITATION FREE.
TEMPERATURES OVER THE WEEKEND ARE FORECAST TO IN THE 30S AND 40S.
GUIDANCE HAS BEEN HINTING THAT A WEAK, MOSTLY DRY COLD FRONT WILL
TRAVERSE THE AREA LATE SUNDAY INTO MONDAY. THIS FRONT WILL LIKELY
ONLY BRING MONDAY'S HIGH TEMPERATURES DOWN A FEW DEGREES COMPARED TO
SUNDAY. THERE IS A REASONABLE AMOUNT OF CONFIDENCE (AROUND 60%) THAT
MILD TEMPERATURES WILL RETURN ON TUESDAY. THERE IS EARLY INDICATION
THAT THE WEST CONUS RIDGE WILL SHIFT EAST BY THURSDAY AND BRING A
RETURN OF WESTERLY FLOW. THIS WOULD MEAN THAT THE REGION WILL BE
ABLE TO TAP INTO PACIFIC MOISTURE AND POTENTIALLY BRING A RETURN OF
SNOW TO WESTERN WYOMING BY LATE NEXT WEEK.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 422 PM MST THU JAN 15 2026
THE MAIN WEATHER IMPACT WILL BE FROM THE COLD FRONT, WHICH IS
CURRENTLY MOVING SOUTHWARDS INTO THE AREA. GUSTY NORTH WINDS ARE
EXPECTED, STRONGEST WITH THE FRONT AND A FEW HOURS AFTER, BUT
PROLONGED GUSTY WINDS ARE EXPECTED INTO FRIDAY. THOUGH IT IS A
MOSTLY DRY FRONT (BESIDES INCREASED CLOUD COVER), A FEW SNOW
SHOWERS ARE POSSIBLE AROUND KCPR (70% BETWEEN 02Z AND 06Z) AND
KCOD (25% BETWEEN 01Z AND 05Z), WITH LESSER CHANCES AT KLND AND
KWRL DUE TO DRY DOWNSLOPING.
AT KJAC, CLOUDS HAVE LASTED LONGER TODAY THAN MODELS ARE DEPICTING.
THESE CLOUDS COULD MORE EASILY REDEVELOP TONIGHT, SO HAVE INCLUDED
MENTION OF LOW CLOUDS IN THE TAF.
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
HIGH WIND WARNING UNTIL 5 PM MST FRIDAY FOR WYZ010-011.
UPDATE...DZIEWALTOWSKI
DISCUSSION...GERHARDT
AVIATION...LAVOIE/WITTMANN
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