Montana Braces For Dramatic Weather Shift

Missoula, MT (KGVO-AM News) - It's been a fantastic fall weather week across the Treasure State, but that's all coming to an end this weekend.

And the latest forecasts are indicating that some of Montana's mountain ranges have the potential to receive more than just a dusting of snow, but more than 2 feet of snow for the high country in the coming days.

It's all due to a combination of Canadian cold air, the so-called "backdoor cold front", combined with subtropical moisture coming off the Pacific.

The forecast has been consistent for more than a week now, with the trend to colder weather continuing in the model runs, and only varying somewhat in the timing of the change.

Friday marks the transition day, starting with gusty winds and near-critical fire weather for Southwest Montana by afternoon, with temps crowding 80 in some locations.

Sun will give way to increasing clouds, with gusts up to 40 mph around Dillon. A lake wind advisory is posted for Flathead Lake with gusts as high as 25 mph, increasing to 35 as the front moves across the region Saturday. The National Weather Service says that could cause damage to boats and docks from Yellows Bay, south and west toward the Narrows and Big Arm.

Clouds, light rain, and gusty winds will mark Saturday, with highs dropping down into the 50s.

By Saturday night, widespread wet, heavy snow will coat mountain passes, including MacDonald and Homestake along I-90. Winter Storm Watches and Advisories warn of tree damage, downed power lines, and slick travel through Sunday night, compounded by remnant tropical moisture tracking north.

Snow levels will drop to between 2500 to 4000 feet, and by Sunday morning, many valley locations could see an inch or more of wet snow, although warm ground conditions could limit significant accumulations.

Backcountry travelers, including hunters, should be ready for raw, hypothermic conditions.

While the peaks along the Northern Divide will see several inches of snow, the storm's real target will be on Big Sky, and the Madison, Gallatin and Beartooth/Absorkee high country. With the potential for prolonged snowfall, some mid-level mountain snow outlooks have been running as high as 22", with more on the highest peaks.

Snowfall totals could range from 6" at Discovery to 17" at Showdown and 14" at Bridger Bowl by the end of next week.

Behind the departing storm, Monday morning lows are forecast to drop into the teens and lower 20s, delivering the season's first hard freeze.

And that cold appears likely to stick through the first part of next week.