The National Weather Service in Missoula is forecasting a major winter storm that will impact western Montana and north-central Idaho through Tuesday night.

In Northwest Montana, the forecast calls for a  mix of rain, snow and freezing rain Monday morning followed by a cold front with precipitation becoming all snow by early Monday afternoon.

Temperatures will continue to hover around freezing through Monday evening. Cold arctic air will arrive Monday night, with travel conditions deteriorating for all area roadways in a likely flash freeze scenario through at least Tuesday morning.

Blowing snow and sub-zero windchill temperatures will be likely near Marias Pass to northern Flathead Valley, including Badrock Canyon, on Monday night. Snow will dissipate Monday night through Tuesday.

On Monday morning, the Montana Department of Transportation reported snow-packed and icy conditions on U.S 2. from West Glacier to the Essex-Marias Pass area. Areas of freezing rain were reported on U.S. 93 south of Kalispell and U.S. 2 west of Kalispell.