680
FXUS65 KRIW 141901
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
101 PM MDT TUE APR 14 2026
KEY MESSAGES
- LIGHT SNOW SHOWER CHANCES (20%) EXIST THROUGH 6PM MDT ACROSS
THE WESTERN MOUNTAINS, THE BIGHORNS, AND CASPER MOUNTAIN.
- A POTENT WINTER STORM SYSTEM IS FORECAST TO BRING WIDESPREAD
PRECIPITATION, WIND, AND FREEZING TEMPERATURES TO THE ENTIRE
AREA BEGINNING LATE WEDNESDAY UNTIL FRIDAY EVENING. CONFIDENCE
IN MEASURABLE SNOWFALL CONTINUES TO INCREASE FOR LOW
ELEVATIONS.
- THERE IS HIGH (90% +) CONFIDENCE IN A HARD FREEZE (28 DEGREES
OR BELOW) ACROSS LOW ELEVATIONS FRIDAY MORNING AND SATURDAY
MORNING, WITH THE POTENTIAL FOR WIDESPREAD LOWS IN THE TEENS
ON SATURDAY MORNING.
UPDATE
ISSUED AT 100 PM MDT TUE APR 14 2026
TODAY'S WEATHER IS ON TRACK TO BE THE LAST TRANQUIL DAY ACROSS THE
AREA BEFORE THE UPCOMING WEATHER SYSTEM. WEAK FLOW WITH RELATIVELY
DRY MID-LEVEL AIR WILL BE PRESENT BEHIND THE DEPARTING TROUGH AND
ALLOW FOR MOSTLY SUNNY SKIES THIS AFTERNOON. EXPECT HIGHS TO BE IN
THE 60S EAST OF THE DIVIDE AND IN THE 40S TO 50S WEST OF THE DIVIDE.
AS MENTIONED IN THE MORNING DISCUSSION, ISOLATED LIGHT SNOW SHOWER
CHANCES (20%) EXIST THIS AFTERNOON ACROSS HIGHER ELEVATIONS AS A
WEAK DISTURBANCE TRAVERSES THE STATE. BREEZY CONDITIONS ARE EXPECTED
WEST OF THE DIVIDE AS THIS DISTURBANCE PASSES OVER THIS AFTERNOON.
ALL ATTENTION CONTINUES TO BE FOCUSED ON THE UPCOMING WINTER WEATHER
SYSTEM THAT IS FORECAST TO IMPACT THE REGION WEDNESDAY NIGHT THROUGH
FRIDAY. THIS SYSTEM, A STRONG COLD FRONT, IS EXPECTED TO BRING
WIDESPREAD WIND, PRECIPITATION, AND COLD. AS THE TROUGH AND
ASSOCIATED COLD FRONT MAKES ITS WAY INTO THE NORTHERN ROCKIES ON
WEDNESDAY, EXPECT STRONG SOUTHWEST WINDS WEDNESDAY AFTERNOON AS THE
PRESSURE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT. FREQUENT WIND
GUSTS OF 25 MPH TO 40 MPH CAN BE EXPECTED ACROSS MOST OF THE AREA
AND RESULT IN ELEVATED FIRE WEATHER CONDITIONS. RELATIVE HUMIDITY
VALUES ARE EXPECTED (70-90%) TO REMAIN ABOVE 20 PERCENT.
THE FIRST PUSH OF THE WINTER WEATHER ARRIVES ACROSS WESTERN WYOMING
WEDNESDAY AFTERNOON. ACROSS THE WESTERN MOUNTAINS, THE MOST LIKELY
PERIOD OF HEAVY SNOW WILL OCCUR EARLY WEDNESDAY EVENING THROUGH
MIDDAY THURSDAY AS THE COLD FRONT MAKES ITS PUSH EAST. SNOW TOTALS
HAVE ALSO TRENDED UP ACROSS THE WIND RIVER MOUNTAINS BEGINNING
WEDNESDAY EVENING, SO THIS AREA HAS BEEN ADDED TO THE WINTER STORM
WATCH. PRECIPITATION WILL THEN SPREAD EAST ACROSS THE REST OF
WYOMING THURSDAY AFTERNOON, MOST LIKELY AS RAIN. THE COLD PUSH
CURRENTLY LOOKS TO NOT ARRIVE UNTIL AFTER SUNSET ON THURSDAY FOR
MOST LOW ELEVATIONS. THANKS TO STRONG COLD AIR ADVECTION, THIS WILL
FEEL LIKE A GOOD PUNCH OF COLD BEHIND THE FRONT WITH 700MB
TEMPERATURES RAPIDLY DROPPING FROM POSITIVE 2 CELSIUS TO NEAR
NEGATIVE 10 CELSIUS IN A MATTER OF HOURS. THIS STRONG NORTHERLY PUSH
WILL ALSO RESULT IN GUSTY WINDS, ESPECIALLY NEAR BUFFALO WHERE THERE
IS AN 85% CHANCE OF 45+ MPH GUSTS. GIVEN THE MOISTURE CONTENT WITH
THIS SYSTEM AND THE COLD TEMPERATURES, THERE IS FAIRLY HIGH
CONFIDENCE (80%+) IN MOST LOW ELEVATION AREAS SEEING MEASURABLE
SNOWFALL BY FRIDAY MORNING. HOWEVER, NO HIGHLIGHTS WILL BE ISSUED AT
THIS TIME FOR LOCATIONS EAST OF THE DIVIDE DUE TO THE GREATEST
IMPACTS OCCURRING IN 2+ DAYS (THURSDAY NIGHT INTO FRIDAY
MIDDAY).
DISCUSSION
ISSUED AT 145 AM MDT TUE APR 14 2026
FINALLY A MORE ACTIVE PATTERN ACROSS WYOMING TRYING TO BRING
PRECIPITATION! THE LATEST SYSTEM IS A TROUGH EJECTING INTO THE
CENTRAL PLAINS FROM THE FOUR CORNERS REGION. THIS SYSTEM IS SET A
LITTLE TOO FAR SOUTH TO BRING A SIGNIFICANT AMOUNT OF PRECIP, BUT
STILL ENOUGH ENERGY TO PRODUCE PRECIP FOR AREAS OF CASPER MOUNTAIN,
THE BIGHORNS, AND HIGHER ELEVATIONS OF THE TETONS.
BUT THIS DOES SET THE TABLE FOR A POTENT LATE WINTER STORM
DIVING OUT OF THE PACNW INTO THE NORTHERN ROCKIES. THIS SYSTEM
STARTS TO SPREAD PRECIP INTO THE NW MOUNTAINS DURING THE DAY
WEDNESDAY BEFORE SLOWLY MOVING EAST THURSDAY AND FRIDAY. THE
SYSTEM WILL BE ACCOMPANIED BY AMPLE MOISTURE, SO THE POTENTIAL
FOR MEANINGFUL ACCUMULATIONS IS IMPROVING. THE SYSTEM WILL ALSO
BE ACCOMPANIED BY A STRONG PUSH OF COLDER AIR, SO MOST PRECIP
WILL BE SNOWFALL, ESPECIALLY THURSDAY NIGHT INTO FRIDAY. THIS
INCLUDES MOST OF THE LOWER ELEVATIONS AS WELL, WITH THE CURRENT
FORECAST TOTALS OF 2 TO 5 INCHES. WINTER STORM WATCHES HAVE BEEN
POSTED FOR THE NORTHWESTERN MOUNTAINS AND YNP FOR THIS SYSTEM,
AND MAY NEED TO BE EXPANDED IS THE SNOW FORECAST INCREASES WITH
LATER UPDATES.
THE OTHER CONCERN WITH THIS NEXT SYSTEM IS THE SIGNIFICANT COLD
AIR PUSH COMING WITH AND BEHIND THE NEXT SYSTEM. COLD
TEMPERATURES WILL ARRIVE DURING THE DAY THURSDAY, WITH LOWS
THURSDAY NIGHT IN THE LOW TO MID 20S EAST OF THE DIVIDE AND IN
THE TEENS WEST OF THE DIVIDE. THE MAIN CORE OF THE COLD AIR THEN
SETTLES IN ON FRIDAY, WITH THE CORE OF THE COLD AIR SETTING IN
FRIDAY NIGHT. PROBABILITIES OF TEMPERATURES FALLING BELOW 28
DEGREES ARE HIGH (>90%), WITH CURRENT FORECAST LOWS REACHING THE
TEENS. THE COMPLICATING FACTOR WILL BE HOW QUICKLY CLOUD COVER
CLEARS OUT BEHIND THE WEATHER SYSTEM, ALLOWING FOR RADIATIONAL
COOLING. IF CLOUDS HOLD LONGER, THESE TEENS WOULD LIKELY NOT BE
ACHIEVED.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1057 AM MDT TUE APR 14 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS NEARLY ALL TERMINALS
THROUGH MUCH OF THE TAF PERIOD. THE ONE EXCEPTION TO THIS CURRENTLY
IS KJAC WHERE SOME LINGER LOW LEVEL CLOUDS PERSIST. CONDITIONS
SHOULD CONTINUE TO IMPROVE SHORTLY AFTER THE START OF THE PERIOD
WITH VFR CONDITIONS LIKELY TO RETURN. A SHOWER OR TWO CANNOT BE
RULED OUT AROUND 21Z TUESDAY NEARBY KJAC. DUE TO LOW CONFIDENCE IN
DIRECT IMPACTS AT THE TERMINAL ONLY A VCSH GROUP HAS BEEN ADDED.
WINDS GRADUALLY INCREASE THIS AFTERNOON WITH NEARLY ALL TERMINALS
SEEING WINDS OF 15 TO 25 KNOTS. THESE WINDS SHOULD DISSIPATE SHORTLY
AFTER SUNSET WITH LIGHT WINDS AROUND 5 TO 10 KNOTS PERSISTING
THROUGH THE OVERNIGHT. A NEARING DISTURBANCE WILL START TO USHER IN
MORE CLOUD COVERAGE FOR WEDNESDAY. WINDS WILL BEGIN TO INCREASE NEAR
THE END OF THE TAF PERIOD MAINLY ACROSS NORTHERN AND WESTERN
TERMINALS. MOUNTAIN OBSCURATION WILL LINGER MAINLY ACROSS WESTERN
MOUNTAIN RANGES AS LOW CLOUDS CONTINUE TO BURN THROUGH THE EARLY
AFTERNOON WITH IMPROVEMENT EXPECTED BY THE MID AFTERNOON.
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
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE
THURSDAY NIGHT FOR WYZ001-002-012.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
AFTERNOON FOR WYZ014-015.
UPDATE...GERHARDT
DISCUSSION...STRAUB
AVIATION...DZIEWALTOWSKI
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