Winter Storm in Lower Clark Fork Region, Montana

MDT declared severe driving conditions on Interstate 90 from Tarkio to Lookout Pass as snowfall rates up to 2 inches per hour were observed. Wind gusts of 30 to 35 mph led to areas of blowing and drifting snow in the mountains. Between 8 to 14 inches of snow fell along the Highway 200 corridor, which led to cancellations of area schools on December 22.

A strong upper level jet and Pacific moisture combined with arctic air stalled over northwest Montana, led to multiple hours of heavy snow rates and difficult travel. Strong arctic winds brought wind chills down to 70 below zero along the Divide and dangerous wind chills across western Montana. A flash freeze and blowing snow were observed across west-central Montana when the arctic cold front pushed through overnight. As skies cleared, extreme cold to 50 below zero were observed along the Divide.