A strong, moist subtropical jet stream overran an arctic front to bring a west to east strip of heavy snow across northeast Montana. Amounts close to a foot were common from Glasgow east to Richland county.

Winter Storm in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 20-DEC-10 00:00:00 to 20-DEC-10 23:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Snowfall ranged from 6.1 inches at the NWS Glasgow office to 12 inches at Park Grove. Most areas reported about 10 to 11 inches as the lower amounts were likely wind blown.

Winter Storm in CENTRAL AND SE PHILLIPS, MONTANA
From 20-DEC-10 00:00:00 to 20-DEC-10 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer in Malta observed 6 inches of new snow.

Winter Storm in DANIELS, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter observed 6.5 inches of snow in Navajo.

Winter Storm in WESTERN ROOSEVELT, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Department of Highways measured 11 inches, while a trained observer reported 9 inches.

Winter Storm in EASTERN ROOSEVELT, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Trained observer 2 miles north-northeast of Froid reported 9 inches of new snow. Culbertson Coop reported 8 inches of new snowfall.

Winter Storm in RICHLAND, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotters reported 6 to 8 inches of snow across the area.

Winter Storm in DAWSON, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Five to eight inches of snowfall were common across the area.

Winter Storm in NORTHERN VALLEY, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Observer 12 miles south-southeast of Opheim reported 6.5 inches of snowfall.

Winter Storm in NORTHERN PHILLIPS, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Two miles south of Whitewater, the spotter estimated 6 inches of snowfall.

Winter Storm in SHERIDAN, MONTANA
From 20-DEC-10 06:00:00 to 21-DEC-10 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Observer 7 miles east-northeast of Medicine Lake observed 7 inches of snow, with snow falling between 0700 and 1600 MST. County official estimated 8 inches of new snowfall.

Winter Storm in GARFIELD, MONTANA
From 20-DEC-10 00:00:00 to 20-DEC-10 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

At least 6 inches of snow fell across the area with greatest amounts likely to have occurred in the central and eastern portions of the zone.

Winter Storm in MCCONE, MONTANA
From 20-DEC-10 00:00:00 to 20-DEC-10 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow amounts of up to 9 inches were reported across the area.