293
FXUS65 KMSO 120930
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
330 AM MDT Wed Mar 12 2025

.DISCUSSION...

KEY MESSAGES:

-  Occasional pass level snow and slick roads, mainly
overnight/early day periods throughout the week

A broad low-pressure system off the West Coast will continue
funneling Pacific moisture into the Northern Rockies today. High-
elevation snow and valley rain will primarily affect northwest
Montana and the Idaho Panhandle throughout the day. As the system
moves east late tonight into Thursday, precipitation will spread
into the rest of western Montana and north central Idaho.

Warm air advection will push snow levels up to 5000 to 6000 feet
by this evening into Thursday morning. However, a passing cold
front will bring snow levels back down to valley floors by
Thursday evening. Most snow accumulation will occur in higher
elevations, with 24-hour ensemble forecasts favoring the
Clearwater and Bitterroot ranges for 2 to 4 inches. Lookout, Lolo,
and Lost Trail Passes have a 40 to 50% chance of exceeding 3
inches by Thursday night. While most valleys will see rain or wet
snow, areas in southwest Montana and Lemhi County may experience
slushy snow accumulations Thursday afternoon and evening,
potentially leading to ice formation on paved surfaces as
temperatures drop. By Friday morning, lows will be 10 to 15
degrees colder than Thursday morning.

The active weather pattern will persist through the weekend into
early next week. Forecast models suggest another low-pressure
trough with a stronger moisture feed and a developing surface low
may impact the region Sunday into Monday. This system appears
slightly colder than the current one, with snow levels between
4,000 and 5,000 feet. Current model probabilities indicate a
70 to 80% chance of at least 6 inches of new snow in the higher
terrain of north-central Idaho and northwest/west-central Montana.
Even valley locations could see light snow, depending on the
timing of precipitation with overnight cooling.

&&

.AVIATION...Valley rain and mountain snow is expected to cause
lowered ceilings and reduced visibility today across northwest
Montana and the Idaho panhandle, including at KGPI. South to
southwest winds are anticipated this afternoon and evening,
especially along and south of the I90 corridor. Gusts as high as
35kts will be possible in the higher terrain, while valleys could
see gusts 15 to 20 kts.



&&

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

$$