623
FXUS65 KMSO 040916
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
216 AM MST Tue Nov 4 2025

.DISCUSSION...

KEY MESSAGES:

- Wet snow through this morning across northwest Montana above
  3,000 feet.

- Active Pacific pattern through this week, with periods of high
  elevation snow.

- High pressure, with drying trend by Sunday into early next week.

Regional radar imagery, along with GOES Satellite, shows a plume
of Pacific moisture moving inland across eastern OR/WA into the
Northern Rockies this morning. A surface boundary has stalled,
along a line from Lookout Pass through Flathead Lake, eastward
towards the divide, where a deep isothermal profile is present.
Area webcams across northwest Montana suggest a couple inches of
wet snow across northwest Montana this morning, with winter
driving conditions being observed across Lookout Pass and US
Highway 2 from West Glacier to Marias Pass. Elsewhere in northwest
Montana, snow has struggled to accumulate onto primary roads thus
far, with minor impacts expected through the morning commute.

This boundary will lift northward through the afternoon, with
south-southwest flow deepening as the next Pacific system moves
onshore in the Pacific Northwest. Snow levels will rise above
7,000 feet Wednesday morning as a warm front arrives, with another
round of precipitation. A break in the action is expected by mid-
day Wednesday, before the next wave of moisture arrives with a
Pacific cold front Wednesday evening into Thursday. Snow levels
will fall to 5,000-5,500 feet as this front passes, with winter
impacts limited to the highest terrain. A southwest-westerly
gradient will focus the precipitation amounts along the ID/MT
border and northwest Montana, with 0.50-1.25 inches in the
terrain. Amounts quickly drop off (<0.10 inches) south and east
of Missoula on US-93 and I-90.

Model guidance suggests yet another Pacific system late Thursday
into Friday. Winds will trend higher on Thursday and Friday ahead
and behind of a potent Pacific cold front. Precipitation will once
again focus along the ID/MT border and mountain ranges in
northwest Montana. Snow levels will trend lower with this system,
reaching 4,500 feet by Friday evening and 3,500-4,000 feet by
Saturday morning. Confidence is high for accumulating snow across
area passes, including Lookout, Lolo, and Marias Passes.

A stronger ridge of high pressure is expected to build over the
Northern Rockies by Sunday into early next week. This ridge will
create stable conditions with light and variable winds which
combined with moist low levels should allow for the development of
fog and/or low stratus in the valleys of the Northern Rockies.

&&

.AVIATION...A surface boundary will remain stationary, from
north-central Idaho into northwest Montana through this morning.
Pacific moisture will continue to stream over this boundary, with
IFR/LIFR conditions across northwest Montana from the combination
of snow, light winds, and stable conditions. Confidence is
increasing for periods of IFR/LIFR fog impacts at KMSO through
04/1400-1500Z this morning given recent observation trends and
continued rainfall. This Pacific system will begin to push north
and east by this afternoon, with improvements to ceilings for
KMSO/KGPI and decreasing shower activity area wide.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until noon MST today for
     Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
     Clark Fork Region...Potomac/Seeley Lake Region...West
     Glacier Region.

ID...None.
&&

$$