An anomalous moisture plume and arctic airmass brought several feet of snow to northwest Montana. Elsewhere, moderate snow brought slick travel along the Interstate 90 and US-93 corridors.

Winter Storm in WEST GLACIER REGION, MONTANA
From 01-DEC-22 00:00:00 to 02-DEC-22 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A moist Pacific front, then arctic front passage initiated very heavy snow rates between 1 to 2 inches per hour, gusty winds to 25 mph with blowing and drifting snow, and very low visibility along US-2 between Hungry Horse and Marias Pass. Heavy snow showers enhanced by the existing arctic airmass caused more accumulation during the later period through early Dec. 2. Total snowfall included: 30 inches Pinnacle, 29.9 inches Essex, 17 inches West Glacier, 16 inches Coram and over 12 inches at Marias Pass.

Winter Storm in KOOTENAI/CABINET REGION, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 11:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy snow, blowing and drifting snow caused very tough driving conditions across the area. Total snowfall amounts include: 22 inches Bull Lake, 12 to 18 inches Libby and Eureka, 7 to 10 inches in both Yaak and Trout Creek. Snow bands brought periods of moderate to heavy snow to US-93 between Olney and Whitefish during the evening of Dec. 1.

Winter Weather in FLATHEAD/MISSION VALLEYS, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Moderate snowfall brought snow-covered roads to the Flathead and Mission Valleys. Snowfall amounts include: 6.8 inches east of Pablo, 6 inches Creston, 5.5 inches Glacier Park International, and 3.3 inches in Ronan.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 13:25:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy snow fell with total amounts up to 18 inches in Heron, 10 inches in Superior, 8 to 10 inches between Dixon and Trout Creek and 5.6 inches in Alberton. Severe driving conditions were hoisted during the early morning hours of Dec. 1 on I-90 from Lookout Pass to milepost 33. Schools in the region were either delayed or closed because of the snow. Black ice with snow showers caused slick conditions and several semi rollovers during the evening of Dec. 1.

Winter Weather in MISSOULA / BITTERROOT VALLEYS, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Snow brought black ice and slick conditions both evenings of the 30th and Dec. 1. A weak arctic front from the north caused gusty north winds to 26 mph and falling temperatures which caused the wet roads to ice up during the late afternoon and evening of Dec. 1 in the Missoula Valley. Multiple vehicle accidents were reported via social media. Total snowfall includes: 4.7 inches four miles west of Missoula, 3.8 inches at the Missoula International Airport, and 1 inch east of Florence.

Winter Weather in BITTERROOT / SAPPHIRE MOUNTAINS, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Periods of moderate to heavy snow fell in the  mountains. Total snow from the two day event included 12 inches at Lolo Pass and 9 inches at Lost Trail Pass.

Winter Weather in BUTTE / BLACKFOOT REGION, MONTANA
From 01-DEC-22 15:30:00 to 01-DEC-22 18:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow Squall Heavy snow with strong winds gusting to 30 mph produced widespread blowing snow and whiteout conditions and a dramatic drop in temperatures and icy roads across both Deer Lodge and Silver Bow counties. A weather spotter located seven miles south-southwest of Butte measured 2.5 inches of snow in 1.2 hours. They also recorded a total snowfall of 4.5 inches.

Winter Weather in POTOMAC / SEELEY LAKE REGION, MONTANA
From 01-DEC-22 00:00:00 to 01-DEC-22 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Periods of moderate to heavy snow through Dec. 1 brought up to 10 inches of snow four miles north of Seeley Lake, and 6 inches in both Clinton and Condon.