Northwest Montana is in for another spring mood swing, with freezing temperatures and valley snow likely Thursday evening.

After a bout of unseasonably warm days to start the week — Kalispell hit 79 degrees Tuesday — temperatures Thursday and Friday will top out in the 40s, with overnight lows falling into the 20s.

“The ridge of high pressure that brought summer-like conditions has moved out as a strong low-pressure system moves onshore across the Pacific Northwest,” the National Weather Service in Missoula noted in its forecast discussion Wednesday.

“Behind the front, temperatures will plummet 30 to 40 degrees compared to Tuesday’s highs.”

Widespread rain is expected to develop Thursday and transition to snow as the cold front takes hold. Snow levels will fall to the valley floor, while nearly a foot of snow could hamper commuters traveling over Marias, Lookout, Lolo, Homestake and MacDonald passes.

A winter weather advisory was issued for the West Glacier region, including Bad Rock Canyon, Polebridge and the Swan Valley, where 4 to 7 inches of snow is likely at pass levels. Up to 3 inches is expected to accumulate in the valley bottoms.

“Travelers should prepare for slushy roads and winter driving conditions,” the forecast stated.

The cool, wet spell will last into the weekend, with high temperatures struggling to hit 50.