textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Expect a warm and dry weekend, with temperatures running about 10 degrees above normal.

- Cooler, showery and breezy on Monday with a passing cold front.

- Potential for a closed low late next week to bring widespread mountain snow, possibly reaching into higher valleys

High pressure will strengthen over the Northern Rockies through the weekend, bringing well-above-normal temperatures. Afternoon highs will reach the 50s and 60s for western Montana valleys, while lower elevations in north-central Idaho will see temperatures climb into the lower 70s. Despite the stable pattern, breezy conditions are expected each afternoon. There is an 80 to 90 percent chance of wind gusts exceeding 30 mph on Sunday, particularly across southwest Montana, Lemhi County, and the Continental Divide. Cloud cover and shower activity will begin to increase Sunday afternoon across northwest Montana as the ridge axis shifts eastward.

A cold front is projected to cross the region Monday, bringing a significant shift toward cooler, unsettled weather. Impactful winds of 30 to 40 mph are expected area-wide, accompanied by widespread rain showers and a slight chance of afternoon thunderstorms. As the front passes, snow levels will drop sufficiently to produce light accumulations on mountain passes, including Marias, Lookout, and Lolo, from Monday evening through Tuesday morning. Travelers should prepare for slick conditions over these higher-elevation routes.

After a brief period of drier weather Tuesday and Wednesday, a more potent weather system is favored to arrive late next week. Nearly 80 percent of ensemble guidance indicates a cut-off low pressure system will impact the region Thursday and Friday. While specific track details remain uncertain, there is growing confidence in a return to much cooler temperatures and widespread precipitation. This pattern would likely bring accumulating snow back to the mountains, with a secondary potential for snow to reach the higher valley floors by Friday.

AVIATION

VFR conditions will prevail through Saturday under building high pressure. Afternoon thermal mixing will result in breezy surface winds across most terminals, particularly Saturday afternoon, with gusts up to 20 knots. Pockets of river fog are possible Saturday morning but will cause minimal aviation impacts for local airfields.

MSO WATCHES/WARNINGS/ADVISORIES

MT...None. ID...None.