026
FXUS65 KMSO 230731
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1231 AM MST Sun Nov 23 2025

.DISCUSSION...

KEY MESSAGES:

- Winter Driving Conditions Return Tonight & Monday AM: Rapidly
  changing visibility and road conditions are expected on passes.
  Localized icy spots, especially in Southwest Montana.

- Transient Arctic push: Along the Continental Divide Monday
  afternoon/evening producing heavy mountain snow, cooling
  temperatures, and wind shift northeasterly.

- Unsettled Holiday Travel (Wednesday & Thanksgiving): Light snow
  returns Wednesday morning. Snow levels rise and precipitation
  transitions to a rain/snow mix later in the day for valleys.

- Potential Arctic Intrusion Late Week (Nov 28-29): Please
  monitor the forecast closely if you have post-Thanksgiving
  travel plans.


Today through Monday:
Stable conditions this morning will support areas of valley fog
and low stratus, though coverage should be less widespread than
Saturday morning. A pattern change begins today as the high-
pressure ridge flattens. Light upslope precipitation will develop
over the northwest MT mountains this morning, preceding a vigorous
cold front that will sweep through the Northern Rockies tonight.
Monday will also be a chilly, blustery day with remnant showers,
gusty westerly winds, and valley highs ranging from the upper 30s
to lower 40s.

Impacts tonight/Monday include:

   -Pass Level: Expect a burst of moderate to heavy snow (2 to 5
    inches) accompanied by 30-40 mph gusts, resulting in rapidly changing
    conditions for travelers.
   -Valleys: Falling temperatures may lead to localized icy
    spots, mainly across southwest Montana on Monday morning.
    While snow levels will crash to valley floors behind the
    front, limited moisture means valley accumulation will likely
    be restricted to a dusting.
   -Glacier Park Region: This area will see more persistent and
    heavier snow, especially late Monday with 7 to 11 inches
    forecast at Marias Pass and 2 to 4 inches in the valleys.

Wednesday and Thanksgiving Day:
Model agreement remains solid regarding a fetch of subtropical
moisture arriving Wednesday morning. Initially, low snow levels
may produce light snow accumulations of an inch or less on valley
floors. Warmer air will gradually lift snow levels from south to
north late Wednesday into Thursday, transitioning valley
precipitation to a rain/snow mix. Slick road conditions are a
concern, especially during the overnight and morning periods.

Next Friday and Saturday (Nov 28-29):
We are closely monitoring this period, as blended guidance
indicates a 60% chance of Arctic air entering western Montana (30%
chance for north-central Idaho). Considerable differences
regarding the timing of the cold air and precipitation amounts
persist. Notably, some AI-based guidance keeps the core of the
cold air along and east of the Divide, limiting impacts. Overall, this
period warrants close monitoring due to the potential for
widespread travel impacts, though many details remain to be sorted
out.



&&

.AVIATION...Patchy fog and low stratus remain a morning concern, though
coverage will be less extensive than Saturday. Moisture streaming
into NW Montana today will drive upslope showers and mountain
obscurations, while VFR prevails elsewhere.

A vigorous cold front crosses the region tonight into early Monday,
bringing precipitation and gusts of 20-30 kts. Snow levels starting near
5500 ft will crash to valley floors by Monday morning, though most
precipitation will end before the changeover. Expect MVFR/IFR ceilings and
visibilities with the frontal passage, creating the greatest impacts at
KGPI and KMSO.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory from 11 PM this evening to 11 PM MST
     Monday for West Glacier Region.

ID...None.
&&

$$