679
FXUS65 KMSO 250852
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
252 AM MDT FRI SEP 25 2026
DISCUSSION
KEY MESSAGES:
- COLD FRONT ARRIVES TODAY BRINGING GUSTY WINDS TO NORTHWEST
MONTANA AND HAZARDOUS, CHOPPY CONDITIONS ON FLATHEAD LAKE.
- CUTOFF LOW THIS WEEKEND BRINGS RAIN AND POSSIBLY SOME SNOW
SHOWERS TO NORTHWEST MONTANA AND GLACIER NATIONAL PARK.
SATELLITE AND RADAR IMAGERY EARLY THIS MORNING PLACE THE
APPROACHING COLD FRONT ALONG THE CASCADE CREST. THE FRONT WILL
PUSH EASTWARD ACROSS THE NORTHERN ROCKIES TODAY, DRIVEN BY AN
UPPER-LEVEL CUTOFF LOW MIGRATING INTO THE REGION THROUGH SATURDAY.
HIGH-RESOLUTION ENSEMBLE GUIDANCE (HREF) REMAINS STEADY REGARDING
WIND IMPACTS BEHIND THE FRONTAL BOUNDARY TODAY. STRONGEST SURFACE
GUSTS REMAIN FOCUSED ALONG A CORRIDOR FROM KILA AND HAPPY'S INN
SOUTH TOWARD HOT SPRINGS, WHERE GUSTS OVER 40 MPH ARE EXPECTED.
WIND WILL ALSO CAUSE CHOPPY, HAZARDOUS CONDITIONS ON FLATHEAD LAKE
WHERE THE LAKE WIND ADVISORY REMAINS IN EFFECT.
MOISTURE TAP WITH THIS SYSTEM IS RELATIVELY MODEST. THE BULK OF
PRECIPITATION WILL SET UP ACROSS CLEARWATER COUNTY, IDAHO UP
THROUGH NORTHWEST MONTANA, WITH STORM TOTAL RAINFALL GENERALLY
REMAINING UNDER 0.50 INCHES. COLD AIR FILTERING IN BEHIND THE
FRONT WILL DRAG FREEZING LEVELS DOWN OVER THE WEEKEND; LATEST
GUIDANCE MAINTAINS ROUGHLY A 30 PERCENT CHANCE OF SNOW AT LOGAN
PASS. WHILE SNOW ACCUMULATIONS WILL BE LIGHT AND ELEVATION-
DEPENDENT, RAW, COLD, AND WET CONDITIONS IN THE GLACIER NATIONAL
PARK BACKCOUNTRY WILL POSE HYPOTHERMIA RISKS FOR OUTDOOR
RECREATIONISTS.
AS THE UPPER LOW DEPARTS, THE NORTHERN ROCKIES WILL SETTLE INTO A
WESTERLY FLOW REGIME THROUGH MID-WEEK. MODEL GUIDANCE IS IN GOOD
AGREEMENT THAT A SECONDARY LOW PRESSURE SYSTEM WILL TRACK WELL TO
OUR SOUTH, MOVING ACROSS CALIFORNIA AND THE GREAT BASIN INTO THE
CENTRAL PLAINS, KEEPING WEATHER ACROSS WESTERN MONTANA AND NORTH-
CENTRAL IDAHO RELATIVELY BENIGN THROUGH THURSDAY.
BY LATE NEXT WEEK AND INTO NEXT WEEKEND, LONG-RANGE ENSEMBLES ARE
BEGINNING TO TREND TOWARD A DEEPER UPPER-LEVEL TROUGH IMPACTING
THE NORTHERN ROCKIES. IF THIS TREND HOLDS, IT WILL BRING A RETURN
OF COOLER TEMPERATURES AND INCREASED SHOWER ACTIVITY TO START THE
FIRST WEEKEND OF OCTOBER.
AVIATION
A COLD FRONT CURRENTLY ALONG THE CASCADES WILL TRACK
EAST ACROSS THE REGION TODAY. EXPECT INCREASING MECHANICAL
TURBULENCE, SURFACE WIND GUSTS, AND MOUNTAIN
OBSCURATIONS—PARTICULARLY OVER NORTH-CENTRAL IDAHO AND NORTHWEST
MONTANA. SHOWERS WILL LOWER CEILINGS AND VISIBILITIES AT KGPI AND
SURROUNDING AIRFIELDS BY LATE AFTERNOON/EVENING, WITH FREEZING
LEVELS LOWERING TO NEAR 6,000 FT MSL BY SATURDAY MORNING.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WIND ADVISORY FROM 2 PM THIS AFTERNOON TO MIDNIGHT MDT TONIGHT
FOR FLATHEAD/MISSION VALLEYS...KOOTENAI/CABINET REGION.
ID...NONE.
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