Extreme Cold/Wind Chill — Toole, Montana

2021-12-31 · Toole, Montana

Event narrative

Sweetgrass mesonet site reports a wind chill of -41.

Wider weather episode

A cold upper level low centered over Canada and its associated upper level trough extending into the Northwestern US brought multiple embedded shortwave disturbances into the Northern Rockies. Meanwhile, at the surface, a cold high pressure system from Western Canada moved southward, eventually settling over the plains of North-Central Montana. This combination of upper level disturbances and very cold air at the surface combined to bring snow and dangerously cold wind chills to the area.

Source: NOAA Storm Events Database, event_id 999248. Narrative written by the NWS forecast office that issued the report.