Montana snowfall totals are set to climb as winter storm warnings stay in effect across several regions through Monday. The sharpest totals are forecast in the mountains, while lower valleys in western Montana may get only a light dusting on grassy surfaces.
Forecasters called for 10 to 20 inches in several warning areas, with isolated amounts approaching 30 inches in the Bob Marshall Wilderness. The gap between valley and mountain snowfall means conditions can change fast over short distances.
Helena Valley warning times
WINTER STORM WARNING remained in effect until 6 AM Monday for the Helena Valley, Madison River Valley, and Missouri Headwaters. That zone called for an additional 3 to 7 inches, with winds in the Helena Valley, Madison River Valley, and Missouri Headwaters gusting as high as 40 mph.
The warning stretched across places where travelers can move from a lighter accumulation into harder driving in a few miles. Snow was expected to remain above 4,000 feet through the weekend, keeping the higher routes in the colder band of the storm.
MacDonald Pass and Butte
WINTER STORM WARNING began at 6 PM Saturday for MacDonald Pass, Homestake Pass, Highway 12 Garrison to Elliston, Georgetown Lake, and Butte, and it was set to run until 6 AM Monday. That area carried total snow accumulations of 3 to 9 inches, with 12 to 18 inches forecast in the higher mountain areas and winds gusting as high as 45 mph.
WINTER STORM WARNING also covered Gates of the Mountains, Upper Blackfoot and MacDonald Pass, Southern High Plains, and Southern Rocky Mountain Front until 6 AM Monday. That warning called for 10 to 20 inches, and gusts could reach 45 mph there as well.
Bob Marshall Wilderness and Flathead Lake
The Absaroka/Beartooth Mountains warning started at 6 PM Saturday and was set to last until noon Monday, with 10 to 18 inches of snow and gusts as high as 35 mph. In the same broad stretch, the forecast called for up to 7 inches in the Lincoln Valley and isolated amounts approaching 30 inches within the Bob Marshall Wilderness.
That split forecast matters on the ground. Lower valleys in western Montana may see only a light dusting on grassy surfaces, while nearby mountain areas can collect enough snow to bury travel corridors quickly. Gusty easterly winds over Flathead Lake were expected through early Monday, with gusts reaching 40 to 50 mph, and a widespread hard freeze was expected in the valleys Monday through Wednesday mornings.
