Cold Arctic air is settling over the Northern Rockies this morning, causing breezy ENE winds and very low wind chills, especially along the Continental Divide (15 to 30 below zero) and valleys near Highway 93 (0 to 15 below). Winds should ease Monday morning. Extreme Cold Warnings and Cold Weather Advisories are in effect through 11AM Monday. Daytime highs will be in the 10s and single digits. Lows will be in the single digits, above and below zero.
The cold air moving over the “warmer” waters of Flathead Lake will create an area of lake-effect snow Monday and Tuesday. A light accumulation of snow will accumulate 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.
_________________
EXTREME COLD WARNING is in effect until 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…