Northwest Montana

Issued: 12/10/2025 8:55 p.m. MST

* WIND ADVISORY THROUGH 8:00 A.M. MST THURSDAY, DECEMBER 11, 2025 *

*FLOOD WATCH THROUGH 5:00 P.M. THURSDAY, DECEMBER 11, 2025 *

Tonight…Occasional rain. Areas of fog. Snow level lowering to near 7000 feet towards morning. Very warm with lows in the mid 30s to mid 40s with mid 30s around 5000 feet. Local gusty southwest winds 15 to 30 mph developing overnight. Gusts to 45 mph possible through favored canyons and along portions of Lake Koocanusa. Very windy across ridge tops with west winds 40 to 50 mph with gusts to 80 mph.

Thursday…Rain and high mountain snow likely in the morning ending by noon. Snow level lowering to near 4000 feet in the afternoon. Snow accumulations of 1 to 2 inches possible above 5500 feet in the morning. Very warm with highs in the 40s to near 50 with near 40 around 5000 feet. Temperatures falling during the afternoon. Windy with west to southwest winds 15 to 25 mph in the morning decreasing in the afternoon. Ridge top winds west 30 to 45 mph with gusts to 60 mph in the morning decreasing in the afternoon.

Thursday night…Mostly cloudy with areas of fog developing overnight. Rain and snow becoming likely from Heron to Trego south with scattered rain and snow showers north of Heron to Trego. Snow level near 2500 to 3000 feet. Snow accumulations of 1 to 2 inches possible above 3500 feet. Lows in the upper 20s to upper 30s with lower 30s around 5000 feet. Light wind.

Friday...Rain and snow likely. Snow level rising to near 3500 to 4000 feet in the afternoon. Snow accumulations of 1 to 2 inches possible above 4000 feet. Highs in the upper 30s to upper 40s with mid 30s around 5000 feet. Light wind. 

Extended Outlook(Saturday through Wednesday):

Saturday...Mainly dry with areas of fog and low clouds in the valleys. A slight chance of mountain showers along the Canadian border. Lows in the 30s with mid 30s around 5000 feet. Highs in the 40s with near 40 around 5000 feet.

Sunday...Areas of fog and low clouds in the valleys otherwise a slight chance of mainly mountain showers. Lows in the upper 20s to mid 30s with mid 30s around 5000 feet. Highs in the 40s with with near 40 around 5000 feet.

Monday and Tuesday...A chance of valley rain and mountain rain and snow. Lows in the 30s with lower 30s around 5000 feet. Highs in the 40s with mid to upper 30s around 5000 feet.

Wednesday...Turning cooler with a chance of rain and snow in the valleys and a chance of snow in the mountains. Lows in the lower to mid 30s with upper 20s around 5000 feet. Highs in the upper 30s to mid 40s with near 30 around 5000 feet.

In-Depth Weather Discussion for Northwest Montana/North Idaho/Northern Rockies 

Issued 11/27/2025 6:50 p.m. MST / 5:50 p.m. PST

SHORT TERM (THURSDAY NIGHT THROUGH SATURDAY):

     As was suggested a couple of days ago the warmer air really never made it much into our part of the Northern Rockies with snow being the primary precipitation type across all of Bonner, Boundary, Lincoln and Sanders Counties thanks to a surface high located across Eastern British Columbia/Western Alberta. The cool air associated with the surface high helped to keep low level winds light northeasterly which is a cold direction for us this time of year and although temperatures aloft slowly warmed throughout the day they remained below freezing which was expected. The sounding from our region actually shows very nicely what is called an isothermal layer meaning that temperatures from the surface up through the atmosphere are at or below freezing which allowed snowfall to be the primary precipitation type. Snow advisories have been issued by NWS Missoula for our Northwest Montana areas with valleys likely to see 2 to 4 additional inches of snowfall below 4000 feet and mountains likely to see 3 to 6 inches above 4000 feet. Similar numbers will be found across North Idaho but as of this writing on Thanksgiving evening no advisories have been issued by NWS Spokane. If you are headed out early on Friday be prepared for slippery and possibly snow covered roads if they are not treated as the snowfall overnight will likely be moderate at times and the ground is finally beginning to freeze which will make things especially slippery. The surface low responsible for the precipitation today will begin to slide by to our south overnight which will help pull lower atmospheric heights and thickness values further south causing colder temperatures. In addition the surface high that has been located across southern Canada will slide south into North Central Montana which will tighten the northeasterly surface pressure gradient. Expect northeast winds to pick up by Friday morning and blow steadily throughout the day in the usual locations with the strongest winds likely to remain across ridge tops, through portions of the Clark Fork River Valley, along portions of Lake Koocanusa and through the Purcell Trench especially around Sandpoint. Some lighter northeast winds will be found elsewhere too but these will subside after sunset on Friday night while the other locations will keep the breezy conditions through Saturday late in the day. Winds won't be terribly strong but noticeable with bite to the air. The colder and drier modified polar airmass will likely help keep stratus and freezing fog to a minimum on Saturday morning but won't completely eliminate it in the more typical valleys sheltered from the wind. Saturday should be a fairly nice day with seasonal or even a bit chilly conditions with at least some filtered sunshine although a bluebird winter day is not likely with a shortwave dropping southeast well to our west across Washington. Northeast winds will begin to diminish by late in the day on Saturday wherever they continue to blow setting the stage for the coldest night of the season on Sunday morning.       

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY):

     The Northern Rockies will remain on the western flank of a large and very cold Hudson Bay low that will largely remain anchored across Manitoba driving some rather cold air southward into the Midwest throughout much of this period. Strong upper level ridging will reside off the Washington coast with the resulting north to northwesterly upper level steering flow allowing various shortwaves to drop into our region and bringing in occasional chances for snow. The strongest of these features looks to arrive later Monday into Tuesday and could bring a few inches of snow to our area in the valleys and perhaps twice that amount to the mountains. Several other weak features will move through during the remainder of the period but trying to time these out with any sort of accuracy this far out is silly at best so have simply broad brushed the extended forecast period with chances for snow showers. Temperatures will see a slow moderation back to near seasonal averages which is mid 30s for valley locations at the beginning of December. Mountains will remain well below freezing so with the combination of the recent and expected snowfall as well as cold temperatures for good snow-making conditions should be able to see our two larger resorts of Schweitzer and Big Mountain be able to open up sometime next week. Check their websites for updates and keep checking back here for the latest forecasts.