Extreme wind chills grip the Flathead

Local wind chill values dipped into dangerous territory Tuesday morning as an arctic air mass enveloped much of Montana.

Gusty east winds dropped the wind chill to minus 63 degrees in the high terrain of Glacier National Park above Avalanche Lake, according to a report from the National Weather Service in Missoula.

Meanwhile, Whitefish Mountain Resort closed its chair lifts on the upper portion of Big Mountain, including Chair 1. A summit temperature of minus 20 and winds at 20 mph dropped the wind chill to minus 48 degrees on the ski slopes.

In the valley, a wind chill factor of 18 below zero was reported at Glacier Park International Airport early Tuesday. The ambient temperature was 2 degrees at sunrise.

A wind chill advisory remains in place for all of Northwest Montana through Wednesday. The Weather Service warned that frostbite on exposed skin could be possible in as little as 10 minutes. People were advised to protect pets and livestock, cover exposed skin and limit exposure times, and travel with a survival kit.

High temperatures Tuesday were only expected to reach the single digits in the valley, with overnight lows plummeting well below zero in many locations, making Wednesday morning the coldest day of the arctic plunge. Lows in Polebridge and West Glacier were expected to fall to 15 to 25 degrees below zero. Most locations will experience the coldest temperatures of the winter.

The polar air mass isn’t expected to budge until the weekend. Overnight lows will continue to be near zero through Saturday morning.

A gradual warming finally returns by Sunday as temperatures rebound to near normal with highs in the mid to upper 30s.