874
FXUS65 KRIW 170116
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
616 PM MST FRI JAN 16 2026
KEY MESSAGES
- STRONG WINDS TO 55 MPH WILL CONTINUE ACROSS JOHNSON COUNTY
TONIGHT. WIND WILL DECREASE AFTER SUNRISE SATURDAY MORNING
WITH GUSTS OF 35 TO 45 MPH THROUGH THE DAY.
- THERE IS AROUND A 30 PERCENT CHANCE OF LIGHT SNOW (LESS THAN
AN INCH) ACROSS THE I-90 AND I-25 CORRIDOR IN NORTHERN JOHNSON
COUNTY FROM TONIGHT TO SUNRISE SATURDAY.
- SEASONAL TEMPERATURES AND MOSTLY DRY CONDITIONS ARE EXPECTED
OVER WEEKEND, WITH LITTLE CHANCE OF PRECIPITATION THROUGH
EARLY NEXT WEEK.
UPDATE
ISSUED AT 1254 PM MST FRI JAN 16 2026
THE STRONG NORTHWESTERLY WIND WILL CONTINUE THROUGH THE DAYLIGHT
HOURS FOR AREAS ALONG AND EAST OF THE DIVIDE. THIS REMAINS MOST
NOTABLE ACROSS JOHNSON COUNTY, WHERE GUSTS HAVE EXCEEDED 70 MPH
AT TIMES TODAY. THIS SHOULD BEGIN TO DECREASE BY SUNSET FOR
MOST LOCATIONS, WITH STRONGER GUSTS PERSISTING IN THE NORTHERN
BIGHORNS AS ANOTHER UPPER JET SURGE ARRIVES. THIS WILL PROVIDE
ENOUGH LIFT FOR LIGHT SNOW IN THE BIGHORNS THIS EVENING (LESS
THAN AN INCH), WITH LOWER CHANCES (20-30%) FOR LIGHT SNOW ACROSS
THE I-90/I-25 CORRIDOR IN NORTHERN JOHNSON COUNTY. OTHERWISE,
NOT MUCH CHANGE IN THE FORECAST; MILD AND MOSTLY DRY CONDITIONS
ARE EXPECTED THROUGH THIS WEEKEND.
DISCUSSION
ISSUED AT 203 AM MST FRI JAN 16 2026
09Z SATELLITE WATER VAPOR IMAGERY SHOWS WYOMING SANDWICHED BETWEEN A
WESTERN CONUS RIDGE AND AN UPPER MIDWEST TROUGH. THIS SET UP IS
RESULTING IN STRONG NORTHERLY FLOW ALOFT, WITH A 100KT TO 130KT
UPPER LEVEL JET OVER THE COWBOY STATE. AN ASSOCIATED
NORTHWESTERLY ORIENTED 50KT-60KT 700MB WIND MAXIMUM IS ALSO
PRESENT OVER JOHNSON COUNTY. THIS SET UP WILL BE IN PLACE
THROUGHOUT THE DAY TODAY WHICH MEANS A WINDY DAY, ESPECIALLY
ACROSS JOHNSON COUNTY, WITH WIDESPREAD COOLER TEMPERATURES IS IN
STORE.
THERE REMAINS HIGH CONFIDENCE (90%+) THAT HIGH WINDS WILL OCCUR MOST
OF THE DAYLIGHT HOURS ACROSS JOHNSON COUNTY, GIVEN LITTLE TO NO
SHIFT IN THE ORIENTATION OF THE 700MB WIND MAXIMUMS AND UPPER LEVEL
JET. HIGH WINDS ARE SUSTAINED GUSTS OF 40 MPH OR GUSTS OF AT LEAST
58 MPH. PROBABILITIES OF THESE GUSTS OCCURRING ACROSS THE
AFOREMENTIONED LOCATION ARE 80% TO 95% THROUGH THE AFTERNOON. THUS,
THE HIGH WIND WARNING REMAINS IN EFFECT FOR JOHNSON COUNTY,
ESPECIALLY NEAR BUFFALO, THROUGH 5PM THIS EVENING. THESE WINDS WILL
ALSO BE PRESENT ACROSS THE BIGHORN MOUNTAINS, HOWEVER, THERE IS
HIGHER CRITERIA FOR HIGH WIND HEADLINES FOR THE MOUNTAIN. A FEW HOUR
EXTENSION PAST 5PM WAS CONSIDERED GIVEN THE OVERALL SET UP REMAINS
MOSTLY IN PLACE. THE ONLY DIFFERENCE IS THAT 700MB WINDS BEGIN TO
DECREASE. WE HAVE OPTED TO NOT EXTEND THE HIGH WIND WARNING GIVEN
PROBABILITIES OF THESE WINDS OCCURRING PAST 5PM DROP TO LESS THAN
20%. REGARDLESS WINDS ACROSS JOHNSON COUNTY, AND ESPECIALLY NEAR
BUFFALO, WILL REMAIN ELEVATED WITH A 50% TO 60% CHANCE OF GUSTS UP
TO 45 MPH OCCURRING THROUGH EARLY SATURDAY MORNING.
GIVEN THE UPPER LEVEL JET STAYS OVER THE STATE TODAY, WINDY
NORTHWEST WINDS ARE ALSO FORECAST ACROSS NATRONA COUNTY, EASTERN
FREMONT COUNTY, THE BIGHORN BASIN, AND HIGH ELEVATIONS ALONG THE
CONTINENTAL DIVIDE. WIND GUSTS ACROSS THESE AREAS WILL GENERALLY
BE BETWEEN 30 MPH AND 40 MPH, WITH AN OCCASIONAL GUST OF 50 MPH
NOT OUT OF QUESTION THROUGH SUNSET THIS EVENING. MEAN 700MB
WINDS OVER THESE LOCATIONS ARE FORECAST TO BE 30KT TO 40KT,
WHICH IS THE REASON THAT THESE AREAS ARE BEING SPARED FROM THE
GUSTS THAT ARE OVER JOHNSON COUNTY. HOWEVER, THIS IS SOMETHING
THAT WILL NEED TO BE MONITORED THROUGHOUT THE DAY AND IF ANY
ADDITIONS NEED TO BE MADE TO THE HIGH WIND WARNING. ELSEWHERE
ACROSS THE AREA, BREEZY WINDS WITH GUSTS UP TO 25 MPH ARE
POSSIBLE (30%-70% CHANCE). WINDS REMAIN WINDY ACROSS MUCH OF THE
AREA INTO SATURDAY BEFORE FLOW ALOFT BECOMES NORTHWESTERLY AS
THE TROUGH SHIFTS EAST AND THE OVERALL PRESSURE GRADIENT WANES.
AS MENTIONED PREVIOUSLY, COOLER TEMPERATURES ARE IN STORE TODAY. A
COLD FRONT ON THURSDAY THAT WAS ASSOCIATED WITH THE BEGINNING OF THE
WINDS, IS NOW WELL SOUTH OF WYOMING. MEAN 700MB TEMPERATURES ARE
FORECAST TO BE -9C ACROSS SOUTHWESTERN PORTIONS AND AROUND -20C
ACROSS JOHNSON COUNTY. WITH DEEP MIXING EXPECTED AND COOL 700MB
TEMPERATURES, NEAR TO EVEN SLIGHTLY COOLER THAN SEASONAL
TEMPERATURES ARE FORECAST WITH TODAYS HIGHS LARGELY IN THE 20S. THE
EXCEPTIONS ARE THE GREEN RIVER, WIND RIVER, AND BIGHORN BASINS AS
WELL AS ACROSS SWEETWATER COUNTY, WHERE HIGHS WILL LIKELY (90%
CHANCE) BE IN THE 30S. FINALLY, THERE IS A UP TO A 30% CHANCE OF
LIGHT SNOW ACROSS THE NORTHERN BIGHORN MOUNTAINS, NORTH OF BUFFALO,
AND ON CASPER MOUNTAIN TODAY GIVEN FAVORABLE UPSLOPING. SNOW
ACCUMULATIONS WILL MOST LIKELY BE LESS THAN 0.5 INCH (80% CHANCE).
THE ONLY IMPACTS THAT COULD OCCUR WOULD BE ASSOCIATED WITH LOW
VISIBILITIES DUE TO BLOWING SNOW.
THERE IS GOOD AGREEMENT AMONGST ENSEMBLE MODEL GUIDANCE THAT LARGELY
UNSATURATED NORTHWESTERLY FLOW WILL BE IN PLACE FROM SATURDAY
EVENING THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THIS IS DUE TO THE
UPPER-LEVEL RIDGE REMAINING OVER THE WESTERN CONUS. EXPECT
TEMPERATURES WARM BACK UP TO ABOVE NORMAL AS WELL. ADDITIONALLY,
WEAK EMBEDDED DISTURBANCES ARE FORECAST TO TREK ACROSS THE REGION ON
SUNDAY, MONDAY, AND TUESDAY. MOISTURE WITH THESE DISTURBANCES WILL
BE LIMITED GIVEN THE OVERALL CANADIAN ORIGIN SO THERE ARE VERY LOW,
IF ANY PRECIPITATION CHANCES. OVERALL, THE DRY AND MILD JANUARY THAT
WE HAVE BEEN HAVING CONTINUES.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 359 PM MST FRI JAN 16 2026
GUSTY NORTH WINDS WILL BE ON A DECREASING TREND THIS EVENING AND
INTO THE OVERNIGHT HOURS. CLOUDS HANG AROUND OVERNIGHT, DECREASING
INTO SATURDAY MORNING, WITH A MOSTLY CLEAR SKY FOR THE AFTERNOON. NO
PRECIPITATION EXPECTED THROUGH THE PERIOD.
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
NONE.
UPDATE...MYERS
DISCUSSION...GERHARDT
AVIATION...WITTMANN
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