Heavy Snow — Northern Blaine County, Montana

2025-12-12 · Northern Blaine County, Montana

Event narrative

A report from the public was received that stated 7 inches of snow fell in Chinook on the 12th. Start, criteria, and end times are all estimated.

Wider weather episode

An initial Canadian cold front brought a much colder airmass southward through North-central Montana to nearly the I-90 corridor on the 11th. As a mid level warm front overran this airmass, instances of heavy snow were observed from the 12th into the 13th. Cold air near the surface and warm nose aloft between the Helena area and Townsend area resulted in significant icing the morning of the 12th.

Source: NOAA Storm Events Database, event_id 1300732. Narrative written by the NWS forecast office that issued the report.