A low pressure system from the Gulf of Alaska descended over the Rocky Mountain region, then moved northeast, emerging over the northern high plains. An arctic air mass from Alberta combined with wamer temperatures from the south to steer plentiful moisture through the area, bringing the first major winter storm of the season to northeast Motana.

Winter Storm in SHERIDAN, MONTANA
From 08-NOV-12 20:00:00 to 11-NOV-12 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snow reports of 6 to 9 inches were common across the area.

Winter Storm in NORTHERN PHILLIPS, MONTANA
From 08-NOV-12 18:00:00 to 11-NOV-12 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

The Morgan Port of Entry reported 9 inches of snow.

Winter Storm in CENTRAL AND SE PHILLIPS, MONTANA
From 08-NOV-12 17:00:00 to 11-NOV-12 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snow reports of 5 to 6 inches were common across the area with a few observers reporting drifts 12 inches high.

Winter Storm in DAWSON, MONTANA
From 09-NOV-12 04:00:00 to 10-NOV-12 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A variety of reports confirmed snowfall totals of 6 to 8 inches in the Yellowstone River Valley with amounts of 10 to 14 inches along the Big Sheep Mountains.  Underlying slick road conditions were also reported due to some freezing drizzle at the onset of the event.

Blizzard in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 09-NOV-12 08:51:00 to 09-NOV-12 12:53:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Blizzard conditions were observed in Glasgow during the late morning hours with one-quarter mile visibility and 35 mph winds.

Winter Storm in PETROLEUM, MONTANA
From 08-NOV-12 10:00:00 to 10-NOV-12 13:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Spotters and cooperative observers reported around 6 inches of snowfall with slick road conditions due to brief freezing drizzle at the onset of the event.

Winter Storm in GARFIELD, MONTANA
From 08-NOV-12 13:00:00 to 10-NOV-12 13:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A variety of spotter and cooperative reports confirmed snowfall totals of 5 to 10 inches across the county.  Road conditions were also slick due to brief freezing drizzle at the onset of the event.

Winter Storm in LITTLE ROCKY MOUNTAINS, MONTANA
From 08-NOV-12 14:00:00 to 10-NOV-12 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative observer at Zortman reported 7.5 inches of snow.

Winter Storm in NORTHERN VALLEY, MONTANA
From 08-NOV-12 16:30:00 to 11-NOV-12 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative observers reported 7 to 10 inches of snow across the area.

Winter Storm in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 08-NOV-12 16:30:00 to 11-NOV-12 12:34:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Multiple sources reported 8 to 12 inches of snow with a maximum storm total snowfall of 12.5 inches at the NWS office in Glasgow.

Winter Storm in EASTERN ROOSEVELT, MONTANA
From 08-NOV-12 18:00:00 to 11-NOV-12 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snow fall amounts of 10 to 12 inches were reported across this area with severe driving conditions being reported by the Montana Department of Transportation.

Winter Storm in DANIELS, MONTANA
From 08-NOV-12 20:00:00 to 11-NOV-12 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative observers and the county dispatch office reported the event began with freezing rain, which created slick roads, then changed over to snow with reports of 5 to 5.5 inches common across the area.

Winter Storm in RICHLAND, MONTANA
From 09-NOV-12 04:00:00 to 10-NOV-12 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Multiple cooperative and CoCoRaHs observers reported a variety of 5 to 10 inches of snow fall while severe driving conditions were reported by the Montana Department of Transporation.

Winter Storm in MCCONE, MONTANA
From 09-NOV-12 04:00:00 to 10-NOV-12 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative observer in the town of Circle reported 6.5 inches of snow.

Winter Storm in PRAIRIE, MONTANA
From 09-NOV-12 04:00:00 to 10-NOV-12 15:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Cooperative observer reported 10 inches of snowfall in Terry with drifts up to 2 feet high.  Icy road conditions were also reported from brief freezing drizzle at the onset of the event.

Winter Storm in WIBAUX, MONTANA
From 09-NOV-12 07:00:00 to 10-NOV-12 17:00:00 (MST-7)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Cooperative observer in Wibaux reported 7 inches of snowfall.  Other reports across the county included freezing drizzle, snow, and melting snow which caused very slick road conditions, resulting in an automobile accident on Interstate 94 with multiple fatalities.  Two pregnant women, not wearing seatbelts, were killed when the vehicle rolled over off the interstate.  Neither fetus survived.  The driver was wearing a seatbelt and had some non-life threatening injuries.

Winter Storm in WESTERN ROOSEVELT, MONTANA
From 08-NOV-12 18:00:00 to 11-NOV-12 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Snow reports of 6 inches were common across the area with freezing drizzle also reported in the late afternoon of the 9th.