A Winter Weather Advisory is in effect on Monday for snow, blowing snow, and brutal wind chill values beginning Monday evening. Snow developing in Northwest Montana will expand across the state Sunday night through Monday. Expect 1 to 3 inches of snow in valleys with passes seeing around 6 inches. Passes over the Bitterroot could see up to a foot of additional snow.
Winds will begin to increase during the day on Monday. Blowing snow on passes means whiteout conditions are possible. Wind gusts over 30 mph are possible Monday night in the Missoula and Flathead valleys. Wind chill values overnight will approach -15 to -30 with severely limited visibility where winds are strongest. Frostbite can occur in less than 5 minutes on exposed skin in these conditions.