The seasons first snow occurred during the second week of October. A surface low moved northeast out of the Four Corners region across Wyoming into the northern high plains. This allowed cold air to move south out of Canada while drawing moisture northward from the Gulf of Mexico. However, most of the cold air was due to dynamic cooling as a result of this powerful low. Heavy snow occurred across the entire Billings Forecast Area with the heaviest occurring across southeast Montana close to the Dakota and Wyoming borders. In addition, very strong northwest winds on the back side of the low resulted in significant blowing and drifting snow across southeast Montana.

Winter Storm in POWDER RIVER, MONTANA
From 12-OCT-21 02:00:00 to 13-OCT-21 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 6 to 16 inches occurred across the area.

Winter Storm in FALLON, MONTANA
From 12-OCT-21 15:30:00 to 13-OCT-21 18:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 4 to 10 inches was reported across the Plevna area.

Winter Storm in BIGHORN CANYON, MONTANA
From 11-OCT-21 12:00:00 to 13-OCT-21 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Fort Smith reported 7 inches of snow.

Winter Storm in SOUTHERN BIG HORN, MONTANA
From 11-OCT-21 07:00:00 to 13-OCT-21 11:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several inches of snow was reported. Key Impact: Aberdeen Hill was closed.

Winter Storm in MELVILLE FOOTHILLS, MONTANA
From 11-OCT-21 05:00:00 to 12-OCT-21 14:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Melville received 8 inches of snow.

Winter Storm in NORTHERN SWEET GRASS, MONTANA
From 11-OCT-21 06:00:00 to 12-OCT-21 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 6 to 7 inches was reported across the area. Key Impacts: poor driving conditions and accidents.

Winter Storm in BEARTOOTH FOOTHILLS, MONTANA
From 11-OCT-21 05:00:00 to 12-OCT-21 14:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Nye reported 6 inches of snow.

Winter Storm in LIVINGSTON AREA, MONTANA
From 11-OCT-21 03:30:00 to 12-OCT-21 14:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 6 to 12 inches was reported. Key Impacts: Multiple accidents on I-90 from Livingston westward over the pass.

Winter Storm in RED LODGE FOOTHILLS, MONTANA
From 11-OCT-21 05:00:00 to 12-OCT-21 14:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Red Lodge reported 15+ inches of snow.

Winter Storm in CRAZY MOUNTAINS, MONTANA
From 11-OCT-21 03:00:00 to 12-OCT-21 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

South Fork Shields Snotel reported 10 inches of snow and Melville reported 12 inches.

Winter Storm in ABSAROKA / BEARTOOTH MOUNTAINS, MONTANA
From 11-OCT-21 03:00:00 to 12-OCT-21 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Snotels reported 14 to 18 inches of snow.

Winter Storm in PRYOR/NORTHERN BIGHORN MOUNTAINS, MONTANA
From 11-OCT-21 04:00:00 to 12-OCT-21 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Area Snotels reported 12 inches of snow.

Winter Storm in CUSTER, MONTANA
From 12-OCT-21 09:00:00 to 13-OCT-21 14:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 6 inches was reported, along with blowing and drifting snow. Key Impacts: Poor driving conditions were reported. U.S. 12 was closed.

Winter Storm in CARTER, MONTANA
From 12-OCT-21 12:00:00 to 13-OCT-21 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall of 7 to 15 inches, along with 50 mph wind gusts, were reported. Key Impacts: severe driving conditions.