A weak disturbance has brought snow to parts of western Montana today. Showers will taper off through the evening, but the light to moderate snowfall could create reduced visibility through the afternoon and slick roads through Monday.
Winter Weather Advisories remain in effect for parts of the area through 5 p.m.
Another surge of arctic air will move into northwest Montana this afternoon, spreading to rest of the area overnight. Tonight and early Monday, temperatures will drop to as low as -20 to -30 in valleys near the Continental Divide, such as Polebridge, Seeley Lake, Ovando, Georgetown Lake, and Butte. Gusty northeast winds 15 to 25 mph will create wind chill values of -30 to -40 below zero Sunday night.
Winds should ease by Monday morning. Extreme Cold Warnings and Cold Weather Advisories are in effect through 11 a.m. Monday.
The cold air moving over the “warmer” waters of Flathead Lake will create an area of lake-effect snow Monday and Tuesday. Several inches of snow are possible along the southern and eastern shorelines.
Arctic cold loosens its grip on western Montana Tuesday, Wednesday and Thursday. Daytime highs will return to the 20s and 30s, with lows in the 10s. However, another surge of arctic air could arrive by the weekend.
An increase in moisture during the time, could result in moderate snowfall.
WINTER WEATHER ADVISORY is in effect until 5 PM Sunday for the Butte/Blackfoot Region, and the Potomac/Seeley Lake Region. Snow accumulations of 1 to 3 inches.
WINTER WEATHER ADVISORY is in effect until 5 PM Sunday for the Missoula/Bitterroot Valleys, and the Bitterroot/Sapphire Mountains. Snow accumulations of up to 1 inch are expected, isolated higher amounts (up to 3″) will be possible.
EXTREME COLD WARNING is in effect from 5 PM Sunday to 11 AM Monday for the Butte/Blackfoot and Potomac/Seeley Lake Regions. Dangerously cold wind chills as low as 30 to 40 below expected. The coldest period will be Sunday night into Monday morning. The coldest wind chills will occur in channeled areas. The dangerously cold wind chills as low as 40 below zero could cause frostbite on exposed skin in as little as 10 minutes.
COLD WEATHER ADVISORY is in effect until 11 AM Monday for the Flathead/Mission Valleys and West Glacier Region. Very cold wind chills as low as 20 to 30 below expected. The coldest period will be Sunday night into Monday morning. The dangerously cold wind chills as low as 30 below zero could cause frostbite on exposed skin in as little as 10 minutes.
COLD WEATHER ADVISORY is in effect from 5 PM Sunday until 11 AM Monday for the Missoula/Bitterroot Valleys and Bitterroot/Sapphire Mountains. Very cold wind chills as low as 15 to 25 below expected. The coldest period will be Sunday night into Monday morning. The dangerously cold wind chills as low as 25 below zero could cause frostbite on exposed skin in as little as 10 minutes…