A strong surface low pressure system moved into the region from Alberta and Saskatchewan on January 9th, departing on the 11th. Meanwhile, a strong northwesterly upper level jet moved across the area on the 10th and 11th, enhancing lift and producing accumulating snow across northeast Montana. In addition to widespread areas of 2 to 5 inches of snowfall, strong winds were brought down to the surface, causing travel difficulties in the form of blowing and drifting snow across roadways as well as reduced visibility. Road conditions were rapidly deteriorating by the morning of the 10th, and did not improve until they were plowed on the 11th and 12th.

Winter Storm in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 10-JAN-18 11:37:00 to 10-JAN-18 14:57:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Reports on the KLTZ radio station's social media page indicated that several people in the town of St Marie could not get out of their driveways due to blowing and drifting snow, and that even an ambulance had to call for a snow plow to get in and out of town. New snowfall amounts ranged from approximately 2 to 5 inches. Time is estimated.

Winter Storm in GARFIELD, MONTANA
From 10-JAN-18 07:00:00 to 10-JAN-18 14:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Montana DOT road condition reports showed snow covered roads as well as blowing and drifting and blowing snow. Highway 200 was snow covered as early as 7:00 AM, and blowing and drifting snow was observed into the afternoon. Approximately 4 to 5 inches of new snowfall was reported.

Winter Storm in DAWSON, MONTANA
From 10-JAN-18 05:30:00 to 10-JAN-18 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Montana Department of Transportation road condition maps showed snow covered roads as well as blowing and drifting snow, starting at around 5:30 AM. Although this continued well into the night, by the evening winds had diminished enough to be below warning criteria. Snowfall amounts of approximately 3 inches were reported.

Winter Storm in PRAIRIE, MONTANA
From 10-JAN-18 05:30:00 to 10-JAN-18 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Montana Department of Transportation road condition maps showed snow covered roads as well as blowing and drifting snow, starting at around 5:30 AM. Although this continued well into the night, by the evening winds had diminished enough to be below warning criteria. Two to three inches of new snowfall was reported.

Winter Storm in WIBAUX, MONTANA
From 10-JAN-18 09:30:00 to 10-JAN-18 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Montana Department of Highways road conditions maps showed significant blowing and drifting snow across roads in Wibaux County. This began around 9:30 AM and persisted into the evening. Snowfall amounts of approximately 3 inches were reported.

Winter Storm in WESTERN ROOSEVELT, MONTANA
From 10-JAN-18 11:37:00 to 10-JAN-18 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Snow and significant blowing snow was reported across roads and highways in the area, starting about 1 PM and lasting into the evening.

Winter Storm in MCCONE, MONTANA
From 10-JAN-18 11:37:00 to 10-JAN-18 19:11:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Snow and significant blowing snow was reported across roads and highways in the area, starting about 1 PM and lasting into the evening. New snowfall totals were approximately 2 to 4 inches across the county.

Winter Storm in RICHLAND, MONTANA
From 10-JAN-18 11:37:00 to 10-JAN-18 19:11:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The combination of light to moderate snowfall and gusty winds created visibility and road conditions issues due to blowing and drifting snow on the afternoon of the 10th. The area received generally between 3 and 5 inches of snow from this storm.

Winter Storm in PETROLEUM, MONTANA
From 09-JAN-18 20:00:00 to 11-JAN-18 09:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Archived Montana Department of Transportation road reports showed poor road conditions with blowing and drifting snow beginning at around 6:00 AM MST on the 10th. Roads continued to be snow covered until around 9:00 AM MST on the 11th. Additionally, a trained spotter located 4 miles east-northeast of Flatwillow reported 8 inches of snowfall that lasted from the evening of the 9th until approximately 1:00 PM MST on the 10th.