Heavy snow fell ahead of a warm front on the 17th, especially across Northwest Montana.  An Arctic front brought strong winds and additional snow late on the 17th into the 18th across all of western Montana.

Winter Storm in FLATHEAD/MISSION VALLEYS, MONTANA
From 17-FEB-18 11:00:00 to 18-FEB-18 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy snow on the 17th with rates of 1 to 2 inches per hour were followed by strong winds the evening of the 17th into 18th. Snowfall totals of 12 to 18 inches were common along with wind gust of 35 to 45 mph.  Severe driving conditions were widespread.

Winter Storm in KOOTENAI/CABINET REGION, MONTANA
From 17-FEB-18 11:00:00 to 18-FEB-18 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy snow on the 17th was followed by snow and gusty winds late on the 17th into the 18th leading to periods of severe driving conditions.  Snow amounts of 8 to 12 inches were common with 18 inches at Marion.

Heavy Snow in BITTERROOT / SAPPHIRE MOUNTAINS, MONTANA
From 17-FEB-18 12:00:00 to 18-FEB-18 20:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy bursts of snow with amounts around 12 inches were common leading to difficult travel over area mountain passes. The highway department noted that it was difficult to keep up with snow rates near Lolo Pass late on the 17th.

Winter Storm in MISSOULA / BITTERROOT VALLEYS, MONTANA
From 17-FEB-18 16:00:00 to 18-FEB-18 20:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Snow, blowing snow, and a flash freeze led to severe driving conditions late on the 17th into the 18th.  Wind gusts of 30 to 40 mph on the morning of the 18th combined with snow to produce greatly reduced visibilities.

Winter Storm in BUTTE / BLACKFOOT REGION, MONTANA
From 17-FEB-18 17:00:00 to 19-FEB-18 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Severe driving conditions were observed on major travel routes due to snow and blowing snow. Wind gusts of 50 to 60 mph were common creating localized ground blizzard conditions.

Winter Storm in POTOMAC / SEELEY LAKE REGION, MONTANA
From 17-FEB-18 18:00:00 to 18-FEB-18 20:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Numerous slide off crashes and jackknifed semi trucks occurred on Interstate 90 due to snow and blowing snow.  Widespread snowfall amounts of 8 to 12 inches were common with wind gusts of 35 to 45 mph.

Winter Storm in LOWER CLARK FORK REGION, MONTANA
From 17-FEB-18 11:00:00 to 18-FEB-18 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Periods of severe driving conditions occurred much of the 17th into the 18th due to heavy snow with some gusty winds.  Twenty-four hour snow amounts included 26 inches at Lookout Pass and 22 inches just west of Trout Creek.

Winter Storm in WEST GLACIER REGION, MONTANA
From 17-FEB-18 12:00:00 to 18-FEB-18 12:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Severe driving conditions with chains required were reported on U.S. Highway 2 from Columbia Falls to Marias Pass due to snow as well as blowing and drifting of snow.  Essex reported 18 inches of new snow.