Heavy Snow — Fergus County Below 4500ft, Montana

2025-12-12 to 2025-12-13 · Fergus County Below 4500ft, Montana

Event narrative

Multiple reports, including from trained spotters and coop observers, reported storm total snow in excess of 6 inches. The peak reports were from Lewistown as well as Grass Range, which were both at a foot.

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 1300730. Narrative written by the NWS forecast office that issued the report.