Ice Storm in Canyon Ferry Area, Montana

Social media report of one quarter of an inch of ice accrual between Townsend and Deep Creek Pass.

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.