Marine Weather and Tide Forecast for Polson, MT

FXUS65 KMSO 112034 AFDMSO

Area Forecast Discussion National Weather Service Missoula MT 134 PM MST Wed Feb 11 2026

DISCUSSION

KEY MESSAGES:

- Benign weather continues for most, with stubborn valley fog and low stratus as the current primary challenge in the Lower Clark Fork and far Western Montana valleys.

- Light snow showers grazing southern Lemhi County today.
Impacts remain minimal and confined to passes.

- Widespread mountain snow and valley rain returns Saturday especially for western slopes, west-central and northwestern Montana.

The Northern Rockies remains in a split flow regime. A closed low near Central California is sending moisture through the Great Basin into Southern Idaho grazing Lemhi County with light snow showers and some minor or slushy accumulations to higher passes along State Highway 28. Elsewhere, the atmosphere is moisture- starved. With quiet weather and slightly above-normal daytime temperatures.

The main forecast challenge continues to be monitoring the sloshing, expansion, and contraction of valley fog and low stratus especially during the overnight and first half of the daytime period. Some mixing during the afternoons may help scour out low- level moisture entirely during the afternoons.

Trends in recent ensemble guidance for locally maximized amounts of moisture from the arriving weekend Pacific Trough has shifted further north over the last 24 hours. At this time, windward slopes in Idaho, West-central and Northwest Montana are the favored locations for widespread precipitation accumulation. While moisture transport with this weekend storm is rather modest, southwesterly flow should be able to produce a widespread 4 to 12 inches of snow in the high terrain from Saturday through Sunday evening.

Snow levels will rise from near 4,000 to 5,000 feet during this event. Consequently, most valleys will see rain or a rain/snow mix, with winter driving conditions confined to passes like Lookout, Marias, Lost Trail, and Lolo. Deep/sheltered valleys in far Northwestern Montana (Tobacco, Yaak, even the Seeley-Swan) may trap cold air longer, supporting a period of wet snow before transitioning toward rain. Expect wet roadways and potential slush or slick spots especially during the overnight.

From next week through at least the 22nd of February, a longwave trough across the Western US will reinforce cool and wet conditions with legitimate chances for all-elevation snowfall as well as significant mountain snow accumulation measured in feet.
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