A series of weather disturbances moved across western Montana over a couple of days. Abundant moisture was associated with these disturbances along with a very strong jet steam. Many locations received heavy snow, especially in the mountains. As the warm and moist air moved into western Montana, pockets of cold air were trapped in some valleys, producing a good freezing rain scenario.  In addition a strong surge of cold arctic air moved across the divide to interact with the warm moist air and produce heavy snow.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 17-NOV-11 00:19:00 to 17-NOV-11 08:08:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer in Olney measured 6.0 inches of snow.

Heavy Snow in POTOMAC / SEELEY LAKE REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 08:45:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter in Seeley Lake measured 3 inches of snow.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 17-NOV-11 17:00:00 to 18-NOV-11 15:43:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer in Libby measured 5 inches of snow.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 09:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

At Libby Dam, 10 miles east of Libby, an observer measured 5 inches of snow.

Heavy Snow in POTOMAC / SEELEY LAKE REGION, MONTANA
From 18-NOV-11 06:00:00 to 18-NOV-11 14:08:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter measured 8 inches of snow in Condon.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 16-NOV-11 10:00:00 to 17-NOV-11 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public estimated 12 inches of snow in 24 hours at Lookout Pass, 5 miles WNW of Taft Montana.

Heavy Snow in POTOMAC / SEELEY LAKE REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 08:08:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

Heavy snow of 3 inches was measured 12 miles W of Ovando at Clearwater Junction.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 08:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter 3 miles N of Eureka measured 4 inches of snow.

Heavy Snow in POTOMAC / SEELEY LAKE REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 08:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

A trained spotter measured 3 inches of snow 1 mile NW of Seeley Lake.

Heavy Snow in POTOMAC / SEELEY LAKE REGION, MONTANA
From 17-NOV-11 00:00:00 to 17-NOV-11 08:45:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter 2 miles SE of Seeley Lake measured 4 inches of snow.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 17-NOV-11 00:00:00 to 18-NOV-11 06:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter measured 6.7 inches of snow 9 miles NNW of Noxon.

Heavy Snow in BITTERROOT / SAPPHIRE MOUNTAINS, MONTANA
From 17-NOV-11 02:00:00 to 17-NOV-11 15:20:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public estimated 9 inches of snow 6 miles SSW of Lolo Hot Springs.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 18-NOV-11 00:00:00 to 18-NOV-11 07:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A spotter 28 miles SSW of Libby measured 4.5 inches of snow.

Heavy Snow in KOOTENAI/CABINET REGION, MONTANA
From 18-NOV-11 00:00:00 to 18-NOV-11 11:25:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer measured 6.3 inches of snow 7 miles NNE of Yaak.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 18-NOV-11 00:00:00 to 18-NOV-11 15:24:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter measured 17.1 inches of snow from midnight to 3pm, 9 miles NNW of Noxon. The snow was falling at a rate of 2 inches an hour.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 18-NOV-11 00:00:00 to 18-NOV-11 20:27:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A trained spotter measured 8.9 inches of snow 2 miles NW of Heron.