760
FXUS65 KMSO 191955
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1255 PM MST WED NOV 19 2025
DISCUSSION
KEY MESSAGES:
- VALLEY FOG: EXPECT REDUCED VISIBILITY DURING THE MORNING
COMMUTE THROUGH FRIDAY, PARTICULARLY IN THE VALLEYS.
- MILD WEEKEND: CONTINUED UNSEASONABLY WARM TEMPERATURES (10 TO
15 DEGREES ABOVE AVERAGE) ARE EXPECTED THIS WEEKEND, WITH
SPOTTY RAIN SHOWERS.
- MONDAY COLD FRONT: A SHARP CHANGE IN WEATHER ARRIVES MONDAY,
BRINGING STRONG WINDS, COOLER TEMPERATURES, AND SNOW TO
MOUNTAIN PASSES.
A WEAK WEATHER SYSTEM IS MOVING THROUGH THE REGION TODAY,
BRINGING SCATTERED SHOWERS PRIMARILY FROM LOST TRAIL PASS THROUGH
GEORGETOWN LAKE AND BUTTE. AS THIS SYSTEM EXITS, SKIES WILL CLEAR
TONIGHT AND WINDS REMAIN LIGHT, THE SETUP IS FAVORABLE FOR THE
DEVELOPMENT OF VALLEY FOG AND LOW STRATUS. THIS PATTERN OF MORNING
FOG FOLLOWED BY AFTERNOON CLEARING WILL LIKELY PERSIST THROUGH
FRIDAY.
THE WEEKEND OFFERS A TASTE OF EARLY AUTUMN RATHER THAN LATE
NOVEMBER. TEMPERATURES ARE FORECAST TO REACH THE MID-TO-UPPER 40S,
WITH SOME VALLEYS NEARING 50 DEGREES, ROUGHLY 10 TO 15 DEGREES
ABOVE AVERAGE. WHILE THE NBM SUGGESTS A 20-40% CHANCE OF RAIN
SHOWERS ON SATURDAY (MAINLY WEST-CENTRAL TO NORTHWEST MONTANA),
GLOBAL FORECAST MODELS (GFS/ECMWF) REMAIN DRIER. IT SHOULD TURN
OUT TO BE A GENERALLY PLEASANT WEEKEND FOR OUTDOOR ACTIVITIES,
DESPITE SOME CLOUD COVER.
THE WEATHER PATTERN SHIFTS ABRUPTLY ON MONDAY. A SHARP COLD FRONT
IS PROJECTED TO MOVE THROUGH, CHARACTERIZED BY:
- WIND: THIS WILL BE A BREEZY SYSTEM. CURRENT PROBABILITIES SHOW
A 50% CHANCE OF WIND GUSTS EXCEEDING 50 MPH ALONG THE
CONTINENTAL DIVIDE AND NEAR ANACONDA. THE BITTERROOT AND
MISSION VALLEYS SEE A 20-30% CHANCE OF SIMILARLY HIGH GUSTS.
- MOUNTAIN SNOW: WHILE NOT A MASSIVE SNOW PRODUCER, THE FRONT
WILL BRING ACCUMULATING SNOW TO THE PASSES. PRELIMINARY
FORECASTS INDICATE TRACE TO 3 INCHES FOR LOOKOUT PASS AND TRACE
TO 6 INCHES FOR MARIAS PASS.
- COOLING: BEHIND THE FRONT, TEMPERATURES WILL DROP BACK TO
NEAR- SEASONAL NORMALS.
LOOKING AHEAD TO THE HOLIDAY TRAVEL PERIOD (WEDNESDAY AND
THANKSGIVING DAY), FORECAST MODELS HAVE TRENDED DRIER. WHILE EARLY
INDICATIONS SUGGESTED AN ACTIVE STORM, THE CURRENT CONSENSUS
POINTS TOWARD SEASONABLE TEMPERATURES AND MAINLY DRY CONDITIONS,
THOUGH A FEW LIGHT MOUNTAIN SNOW SHOWERS CANNOT BE RULED OUT. IT
IS WORTH NOTING THAT THE PATTERN IS STILL EVOLVING. TRAVELERS
SHOULD MONITOR UPDATES, AS EVEN SMALL SHIFTS IN THE JET STREAM
COULD RE-INTRODUCE LIGHT SNOW TO THE FORECAST FOR BOTH VALLEY AND
PASS-LEVEL TRAVEL.
THE DAY AFTER THANKSGIVING, BLACK FRIDAY, CAN BE A BUSY TRAVEL
DAY, AND THE WEATHER PATTERN LOOKS UNSETTLED. THE NBM HAS 20 TO
40 PERCENT CHANCE FOR SNOW IN THE VALLEYS, AND 60 TO 80 PERCENT
CHANCE FOR SNOW OCCURRENCE IN THE MOUNTAINS.
AVIATION
A LINE OF SHOWERS WILL CONTINUE TO IMPACT SOUTHWEST
MONTANA THROUGH 20/0000Z, GENERALLY ALONG A LINE FROM LOST TRAIL
PASS TO MACDONALD PASS SOUTH AND EAST. SNOW SHOWERS WILL OBSCURE
TERRAIN, WITH A 30% CHANCE FOR BRIEF VISIBILITY REDUCTIONS DOWN TO
1-2SM AT KBTM. AS THIS SYSTEM EXITS, SKIES WILL CLEAR TONIGHT,
AND PATCHY FOG IS POSSIBLE THURSDAY MORNING. WHILE A WEAK
DISTURBANCE COULD BRING A FEW SHOWERS ACROSS NORTH- CENTRAL IDAHO
THURSDAY, THE REMAINDER OF THE REGION WILL HAVE VFR FLYING AFTER
ANY MORNING FOG BURNS OFF. LOW CLOUDS OR FOG IS AGAIN POSSIBLE
THURSDAY NIGHT INTO FRIDAY.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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