The January thaw that has turned the Flathead Valley into a soupy, slushy mess is expected to give way to another shot of significant winter weather beginning Wednesday.

Northwest Montana valleys could be buried in a fresh 10 inches of new snow by Friday.

After temperatures on Monday reached 40 in Kalispell under mostly sunny skies, colder air is expected settle over the Flathead on Wednesday. Up to 3 inches of snow possible in valley locations with this initial push of winter weather, the National Weather Service in Missoula said in its daily forecast discussion.

An advisory was issued for the West Glacier region with 5 to 6 inches of snow expected in lower elevations and up to 10 inches possible for Marias Pass.

The winter weather really ramps up Thursday into Friday, the Weather Service said.

Most valleys of Western Montana will experience a wintry mix as substantial moisture arrives with a warm front Thursday. Mountain terrain, however, should expect moderate to heavy snowfall during this period.

Snow levels drop once again as a cold front swings through the region Thursday night.

“It is along and after the passage of the cold front that the valleys should experience their best chance of snow,” the Weather Service warned.

By Friday afternoon, the mountains could see between 10 to 20 inches of new snow. Blowing and drifting is possible on Marias Pass. The valleys of Northwest Montana should expect 4 to 9 inches of snow by Thursday night.

High temperatures are expected to be in the 30s in Kalispell through the weekend with lows in the 20s.