A WIND CHILL WARNING remains in effect for northern Montana into Saturday for wind chills as low as -55 to -60.
A WIND CHILL ADVISORY remains in effect for southern Montana into Saturday for wind chills as low as -40.
An extremely cold wind chill value of -70 was recorded near West Glacier on Thursday morning. This is life threatening cold and frost bite could occur in a matter of minutes in these conditions. While this was an extreme measurement, wind chills will continue to be between -40 and -60 for much of the state through Friday and into the weekend. The core of the arctic airmass is currently over the state and will continue through the weekend with no real relief from the dangerous cold. Moderation will begin on Monday as the arctic airmass slowly moves east.
Another round of snow will move through southwest Montana on Friday. Some very light snow will reach as far north as Helena but it's really along I-90 and south where any appreciable accumulation will be. There will be partly cloudy skies farther north and east. Most areas will see highs between 0 and -15. Friday night will be bitterly cold with lows between -15 and -30. Some of the coldest spots will be near -40 without the wind. Saturday will again have very light snow in the southwest part of the state, with some flurries as far north as Helena. Highs will be teeth-chattering cold between 0 and -10 again. Saturday night will be one more night with potential record cold of -20 to -40. Sunday will be mostly cloudy west, but mostly sunny north. Highs will be in the -0s to the 0s. Monday is Presidents' Day and this is when some temperature moderation is likely. However, light snow is likely for much of western and central Montana. Accumulation will be light with at most a couple inches falling. Highs will likely warm into the 10s and 20s (above zero). Tuesday will be mostly cloudy with scattered light snow showers, highs will rise into the 20s. By Wednesday, the arctic air will be in full retreat mode and temperatures will climb into the 20s and 30s. Some areas will get above freezing by Thursday.
This is the coldest air in 2 years. Please use extreme caution if you must go out and about. A simple slide off the road could become life threatening in these conditions.