BOZEMAN – A dynamic weather pattern to impact Montana this weekend. Long fetch of moisture is following the Polar Jet Stream through the Pacific NW into Montana Friday afternoon. A Low-pressure system will develop beginning Saturday allowing much colder air to drop down into Montana and create lowering snow levels.
Friday night through Sunday night all mountain ranges will see snow and it could be heavy at times. Above 6,000’ look for snow totals in the neighborhood of 6”-12” and above 7,000’ snow totals could exceed a foot. Higher peaks around SW Montana could see up to 2’ feet of snow.
Be prepared for significant travel impacts across all mountain passes Friday night through Sunday night.
Valley floors should see mostly rain Friday night into Saturday morning. Temperatures will continue to cool down by Saturday afternoon enough to change rain into snow. All valleys could see snow accumulations Saturday night into Sunday morning. Again, be prepare for slow-go winterlike travel conditions this weekend.
The National Weather Service has issued widespread Winter Storm WARNINGS across SW Montana from Midnight Friday to 6 pm Sunday.
West of the divide above 6,000’ heavy snow is possible with estimated snow totals of 6”-10” and above 7,000’ 9”-15”+ is possible. Butte, Anaconda, Deer Lodge areas could see 2”-6” of valley snow mostly Saturday night into Sunday morning.
East of the divide the Upper Big Hole region around Wisdom to Wise River could see 4”-6” of valley snow and up to 15” or more over mountain ranges. Wind gusts to 45 mph are also possible.
Tobacco Root, Centennial, Madison, Gallatin ranges could see 4”-6” of snow around 6,000’ or more and above 7,000’ up to 20” is possible along with wind gusts to 45 mph.
Bridger range up through the Big Belt ranges could see 3”-6” of lower elevation snow with 10”-20” of higher elevation snow along with gusty surface wind.
Absaroka-Beartooth ranges look for 12”-24”+ of snow this weekend with wind gusts up to or over 50 mph.
The National Weather Service issued a WINTER WEATHER ADVISORY from 6 pm Saturday to 6 pm Sunday.
This includes the Bozeman to Whitehall stretch of I-90, Whitehall to Dillon to Lima. US 287 to Ennis southward. Three Forks to Townsend to Helena. Helena to Great Falls to Lewistown. Missoula to Lookout Pass.
Lower valleys could see 2”-6” of snow Saturday night into Sunday morning.