951
FXUS65 KMSO 280753
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1253 AM MST Fri Nov 28 2025

.DISCUSSION...

KEY MESSAGES:

- A strong cold front moves north to south across western Montana
  and central Idaho today causing widespread winter weather.

- Low confidence, but north to south snow bands are possible late
  this afternoon and evening, especially around Missoula.

- The coldest temperatures of the season so far expected this
  weekend.

- Another round of snow Monday night through Wednesday morning
  will cause some minor impacts to travel.

- Overall, the weather pattern will remain active through the
  week.

Last night a cold front was stalled out along the Continental
Divide and the Canadian border. A cutoff low is coming in from the
west and rejoining the main storm track over our region early this
morning just as a fast moving trough out of the northwest comes
into our region. The merger of these two systems is occurring this
morning. The cutoff low from the west is bringing most of the
moisture with the trough from the northwest bringing lots of lift
and a very cold front at the surface. The confluence of these two
systems will focus the worst weather along the Continental Divide,
where we currently have winter storm warnings out. The combination
of plenty of moisture and temperatures just above freezing
dropping into the mid 20s with the front makes icing on roads with
the front a big concern. Otherwise, snow amounts forecast in the
valleys of western Montana are modest, though many mountain
locations may pick up near a foot of snow. Heavier snow amounts
today from 6-8 inches will affect Lookout, Lolo, Lost Trail,
MacDonald, and Marias Passes. Homestake pass will receive less
snow, but it`s proximity to cold air mass east of the Continental
Divide is concern for icing along I-90.

A building ridge this evening will cause a descending dry, stable
layer this afternoon. This is a good pattern for snow bands to
become established in the afternoon and evening, and models
frequently miss it. The north winds below the stable layer in this
pattern have, in the past, interacted with the mountains to cause
persistent snow showers over Missoula. This is a finicky pattern
that is NOT handled by models well, if at all. Confidence is low,
but snow may last much longer into the evening here than currently
forecast. And if it does, it will most likely be in a narrow band
from north to south maybe 5-miles wide.

Behind the trough on Saturday a very dry northwest flow ushers in
a cold air mass. The combination of recent snow, a cold air mass,
and a very dry air mass will cause strong nighttime cooling with
most of western Montana dropping into the low single digits
Saturday morning. Sunday morning will be similarly cold.

Northwest flow remains the pattern for the rest of the week with a
trough moving through every few days. That will keep the snow
coming in small doses, as none of these shortwave look as moist as
the today`s front.



&&

.AVIATION...A cutoff low from the west rejoining the jet stream is
merging with a fast moving trough from the northwest over the
region this morning. That will cause low ceilings and moderate
snow at times. With the passing cold front today, we expect that
snow will accumulate at all area terminals where it occurs this
afternoon and evening. That includes KGPI, KMSO, KHRF, and KBTM. A
descending dry, stable layer this evening with light north flow
may cause some light snow showers to persist longer than models
suggest, especially for terminals KMSO and KHRF.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 5 PM MST this afternoon for
     Bitterroot/Sapphire Mountains...Flathead/Mission Valleys...
     Kootenai/Cabinet Region...Lower Clark Fork Region...
     Missoula/Bitterroot Valleys.

     Winter Storm Warning until 2 PM MST this afternoon for West
     Glacier Region.

     Winter Storm Warning until 6 PM MST this evening for
     Butte/Blackfoot Region...Potomac/Seeley Lake Region.

ID...Winter Weather Advisory until 4 PM PST Friday for Southern
     Clearwater Mountains.

&&

$$