Northwest Montana

Issued: 03/25/2026 8:10 p.m. MDT

Tonight...Partly cloudy this evening with isolated to widely scattered snow showers then scattered snow showers developing overnight, ending towards morning. Local snow accumulations of up to 1 inch possible above 3500 feet. Lows in the 20s to near 30 with near 20 around 5000 feet. Evening west to southwest wind 10 to 20 mph becoming light. Ridge top winds west 15 to 25 mph with gusts to 40 mph.

Thursday…Partly cloudy. Isolated early morning snow showers especially north and east of Libby. Highs in the 40s to near 50 with near 30 around 5000 feet. West to southwest wind 10 to 20 mph with gusts to 30 mph through favored canyons and along portions of Lake Koocanusa. Ridge top winds west 15 to 30 mph with gusts to 40 mph.

Thursday night…Fair skies. Lows in the upper teens to mid 20s with lower 20s around 5000 feet. Evening west to southwest wind 10 to 20 mph becoming light. Ridge top winds west to southwest 15 to 30 mph.

Friday...Mostly sunny and warmer. Highs in the 50s with mid 40s around 5000 feet. Light north wind.

Extended Outlook(Saturday through Wednesday):

Saturday and Sunday...Dry and unseasonably warm. Lows in the mid 20s to mid 30s except near 40 in thermal belts on slopes and hillsides with upper 30s around 5000 feet. Highs in the mid 50s to lower 60s with upper 40s around 5000 feet.

Monday and Tuesday...A chance of valley rain showers and mountain snow showers. Lows in the 30s with lower 30s around 5000 feet. Highs in the upper 40s to mid 50s with upper 30s around 5000 feet.

Wednesday...A chance of valley rain and snow and mountain snow. Lows in the upper 20s to mid 30s with upper 20s around 5000 feet. Highs in the 40s to near 50 with upper 30s around 5000 feet.

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

Issued 03/22/2026 8:05 p.m. MDT / 7:05 p.m. PDT

SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY):

     Strong upper level ridging that has dominated much of the Central and Western Half of the lower 48 will amplify a bit on Monday ahead of a deepening upper level trough that is pushing through the Eastern Pacific. As this deepening upper level trough continues its eastward trek it will help to pick up a surface low that is currently spinning north of the Hawaiian Islands. This surface low will rapidly deepen as it encounters the jet dynamics of a rather active North Pacific polar jet stream which will be the driver for the amplification of the upper level ridge across the Western US. Monday will see an increase in high level cloudiness which may make for more of a filtered sunshine in the afternoon and not as much blue sky as was the case on Sunday region wide. Warm air advection will be taking place however so after a seasonably cool start on Monday temperatures will warm further and be close to 6 to 10 degrees above late March seasonal averages across the region. By Monday night cloud cover will be fairly extensive so temperatures will not be nearly as chilly Tuesday morning as they will be Monday morning and well above seasonal averages. As the approaching upper level trough and surface low pushes into the West Coast a strong baroclinic zone with strong forcing(vertical motion) and surface convergence will develop and help cause some very beneficial rains to develop and fall across all of the Northern Rockies starting across North Idaho around or either side of noon and by early to mid afternoon across Northwest Montana. Unfortunately with warm air advection being one of the drivers of the strong vertical motion along the baroclinic zone this will mean snow levels rising above most mountains in our region with the exception of those highest peaks above 6500 feet or so. Rainfall looks to be be between 0.25 inches in the drier parts of Sanders and Lincoln Counties in Northwest Montana to perhaps an inch or more in the wetter areas of Bonner County and Lincoln/Sanders Counties. Temperatures will be cooler on Tuesday thanks to the clouds and precipitation.     

LONG TERM (TUESDAY NIGHT THROUGH SUNDAY): 

     The incoming upper level trough and baroclinic zone will push across the region overnight Tuesday bringing a 12 to 18 hour period of steady, stratiform precipitation mostly in the form of rain before snow levels come crashing down towards morning on Wednesday. During the day on Wednesday, a cold and conditionally unstable airmass within the upper level trough will pass overhead and provide shallow instability to generate scattered to numerous rain and snow showers with snow levels lowering down to near valley floors. These types of patterns often favor North Idaho and Northwest Montana west of the Cabinet Mountains with the most frequent showers with other locations seeing more isolated to scattered showers. Higher elevations could pick up a few inches of snow above around 5000 feet especially in the Selkirk and Cabinet Mountains. A cool and conditionally unstable westerly flow will persist on Thursday across the Northern Rockies and with daytime heating will likely see a few more rain and snow showers develop although not as widespread as what will fall on Wednesday. There may be slightly better coverage across Northwest Montana on Thursday with perhaps a bit better instability residing across this region but that remains to be seen. By Friday and lasting into next weekend another upper level ridge will build across the Western US ahead of yet another digging and amplifying upper level trough in the Pacific. This ridge also looks to be rather transient but should provide at least 2 to 3 days of warm and somewhat sunny weather. Temperatures will once again soar to around 10 degrees above late March seasonal averages next weekend. A final note: last weeks abundance of cloudiness and yet little rainfall overall was attributed to a so called "atmospheric river" and most TV weather people and meteorologists were focusing on how much moisture there was in the atmosphere associated with this. While there was an abundance of moisture there really was not a lot of precipitation that fell anywhere other than in the Cascade Mountains. If moisture is the primary ingredient needed for precipitation then our entire region should have seen copious amounts of precipitation but the truth is that this simply did not happen. The areas that did see some more significant precipitation were focused in the mountains once again proving that moisture is simply a by product of vertical motion through the atmosphere and NOT a primary ingredient. So the next time you hear someone talking about moisture being a primary ingredient for precipitation, remind them that this is simply FALSE and that vertical motion through the atmosphere is the primary ingredient to generate precipitation.