921
FXUS65 KMSO 270800
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
100 AM MST Thu Nov 27 2025

.DISCUSSION...

KEY MESSAGES:

- Mixed precipitation chances this morning.

- Major winter weather impacts: Backdoor front, strong winds, much
  colder with widespread snow for Black Friday.

Warmer air aloft has continued to move into the region through
last night. Persisting valley cold pools may remain strong enough
for melted precipitation to become freezing rain especially in
areas south of US-2 through Thursday afternoon. While total
accumulations of both ice and snow will remain light, even a small
amount of ice or snow falling on cold ground surfaces could create
slick roadways. Areas north of US-2 have the highest chance to see
all precipitation remain as snow even in valley locations.

All attention turns toward a much more impactful storm Thursday
night into Friday as the coldest temperatures of the season, so
far, begin to work their way south and west across the Continental
Divide with the arrival of a sharp, yet modified Arctic air mass.

The main concerns from this weather event will be the sudden drop
in temperatures (10-15 degrees) and associated gusty winds (up to
40 mph) in many locations which could lead to an abrupt change in
precipitation type back to snow along with the potential for
rapidly freezing roadways especially where precipitation has
fallen on Thursday.

Strong frontogenesis along this "Arctic" boundary along with a
deep moisture profile will support intense mesoscale banding which
could produce bursts of heavy snowfall intensities and
significantly reduced visibilities.

Confidence is highest in the most significant impacts being along
and near the divide including Glacier National Park, Marias Pass,
the Seeley/Swan region, and Powell, Granite, Silver Bow, and Deer
Lodge Counties (where Winter Storm Watches have been issued) with
reduced confidence in the arrival of the bitter cold and heavy
snow as you head west.

Through the rest of the weekend and into next week, anticipate
cold, though mostly dry, conditions as the storm system departs
leaving the Northern Rockies in north-northwesterly flow. Slight
chances for snow will continue under this pattern.

&&

.AVIATION...A ridge building over the region is causing increasing
stability and light, very light at times precipitation at times.
Snow levels are rising, and only snow and rain is expected to
affect area terminals. The area around terminal KGPI has quite a
lot of boundary layer moisture causing fog and low ceilings at
times. With the building ridge and cloud cover coming over the
ridge, there won`t be enough instability or sunshine to help clear
it out, so conditions are expected to remain challenging at KGPI
until the east winds pick up out of Badrock Canyon late tonight.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory from 11 PM this evening to 5 PM MST
     Friday for Bitterroot/Sapphire Mountains...Kootenai/Cabinet
     Region...Lower Clark Fork Region...Missoula/Bitterroot
     Valleys.

     Winter Storm Watch from this afternoon through Friday afternoon
     for West Glacier Region.

     Winter Storm Watch from this evening through Friday afternoon
     for Butte/Blackfoot Region...Flathead/Mission Valleys...
     Potomac/Seeley Lake Region.

ID...Winter Weather Advisory from 10 PM Thursday to 4 PM PST Friday
     for Southern Clearwater Mountains.

&&

$$