282
FXUS65 KMSO 162004
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
204 PM MDT Thu Oct 16 2025

.DISCUSSION...

KEY MESSAGES:

-  Scattered showers and gusty winds return on Friday
   afternoon/evening

-  Minor travel impacts are possible over mountain passes Sunday
   night/Monday due to snowfall

Persistent stratus across western MT and north-central ID is
slowly eroding this afternoon due to mid-level dry air
entrainment and increasing winds aloft. Stratus is expected to
lift and dissipate for most areas through this evening, though
locations nearest the Continental Divide and northwest Montana
will be the last to clear, and may not fully do so until tomorrow.

On Friday, a fast-moving clipper like system will traverse the
region. The primary impact will be gusty winds, which will also
mix out any lingering stratus. Probabilities for gusts reaching 30
mph are 40-60% for the higher terrain and valleys of western MT.
A lower probability (20-30%) exists for gusts exceeding 40 mph,
mainly along the Continental Divide into southwest MT. Anticipate
choppy conditions on area lakes. Showers will primarily be limited
to the higher terrain, with snow levels remaining above 5500
feet, resulting in minor accumulations only in the high
backcountry.

A shortwave ridge will provide a period of dry and pleasant fall
weather on Saturday. However, the pattern becomes active again on
Sunday. The next system, a cold front associated with remnants of
an atmospheric river, will arrive late Sunday morning and
afternoon, bringing widespread showers and gusty winds. Snow
levels will fall significantly, starting near 7000 feet on Sunday
and dropping to 4500-5000 feet by Sunday night.

The primary impact will be accumulating snow for mountain passes
Sunday night into Monday morning, enhanced by lingering showery,
upslope flow. Current mean forecast snow totals are 2-4 inches for
Lolo, Lookout, Lost Trail, and Marias passes, with 4-8 inches in
the higher terrain. This will create cold, snowy, and hazardous
conditions for backcountry users. While valleys may see snow mix
with rain by Monday morning, no valley accumulation is expected.



&&

.AVIATION...Prevailing low stratus has begun to erode under
increasingly dry northerly winds aloft. Mountain obscurations are
still possible through the evening due to the broken cloud deck.
If complete clearing occurs across the region before sunset, low
stratus into Friday morning will be much less likely. If a broken
low cloud deck remains below mountain ridgelines through sunset,
there is the potential for localized lowering ceilings or valley
fog into the morning. Highest chances for continued fog or
stratus will be across southwest Montana and the Continental
Divide. Widespread west winds gusting up to 25 knots will begin
to further scour out low level clouds in most locations by
17/1800z. There is a low (~20%) chance of 35 knot gusts or more
especially near any stronger shower or storm outflow. Chances for
showers and an isolated thunderstorm between 17/1800z and 18/0600z
under west-northwesterly flow could cause brief deterioration in
flying conditions, and lowered ceilings. Clearing and drying
expected into Saturday with the potential for some morning valley
fog or low stratus.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$