775
FXUS65 KMSO 120942
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
242 AM MST Wed Feb 12 2025

.DISCUSSION...

KEY MESSAGES:

-  Very cold temperatures across western Montana through
    Thursday

-  Return of snow late Thursday into next week, with gradual
   warming.

-Wintry mix in the valleys by Sunday-Monday.

A bitterly cold morning grips the region once again, with temperatures
of -15F to -25F for valleys along the Divide. Further west and
into north- central Idaho, a layer of stratus clouds has provided
slight insulation, keeping temperatures marginally warmer.

Early this morning, a disturbance which is dropping south from
the Canadian Rockies is reinforcing cloud cover and producing
scattered flurries and light snow showers. Aside from this, the
main weather story today remains the intense cold with daytime
temperatures expected 20-25 degrees below normal. Cold advisories
may need to be extended into Thursday morning, particularly along
the Divide as another very cold night is anticipated.

Looking ahead, the next impactful weather system is on track to
arrive late Thursday afternoon lasting into Saturday morning as a
broad trough moves onto the Northwest Pacific Coast. This will
bring a widespread light to moderate snow event, driven by a
southwest flow of Pacific moisture overrunning the entrenched cold
air. Current projections suggest a 50-80% probability of at least
one inch of snow across most valleys. In fact, median values of
the NBM even show 2-3 inches of snow for the Camas Prairie and
Orofino. Additionally, forecast models continue to indicate a
reinforcing surge of Arctic air into northwest Montana/along the
Divide by Friday morning, increasing the likelihood of localized
blowing and drifting snow.

By Sunday, weak warm-air advection could raise snow levels enough to
introduce the possibility of freezing rain in lower valleys of the Northern
Rockies, mainly south of I-90. However, confidence in this
transition remains low, as these weaker systems often struggle to
displace entrenched valley cold pools. The Sunday-Monday timeframe
warrants close monitoring, as any freezing rain event could
significantly impact travel conditions. Regardless, slick roads
are still likely from periodic snowfall. Also, there has been a
trend toward another weak push of Arctic air along the Divide by
Tuesday morning with wintry impacts continuing into the middle of
next week under northwest flow.


&&

.AVIATION...A weak shortwave moving south through the Northern Rockies is
generating stratus clouds, occasional mountain obscurations, and
scattered flurries/light snow showers. A mix of sun and clouds is
anticipated later today behind the disturbance. Lastly, cold air
remains firmly in place, accompanied by light and variable winds.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Cold Weather Advisory until 1 PM MST Wednesday for
     Bitterroot/Sapphire Mountains...Butte/Blackfoot Region...
     Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
     Clark Fork Region...Missoula/Bitterroot Valleys...
     Potomac/Seeley Lake Region...West Glacier Region.

ID...None.
&&

$$