Extreme Cold/Wind Chill in Fergus County Below 4500ft, Montana

Many sensors measured criteria cold, including mesonet station MTM42 Blm Roy, which measured a wind chill of -46F.

A stout closed low over Manitoba swung a shortwave around its western periphery and then southward toward the Northern Rockies Feb 16. The wave stalled over MT, resulting in a strongly cyclonic flow aloft, while the main upper disturbance exited eastward.. This allowed for a long duration snow event that lasted into the 18th.

After this system cleared out, a strong surface high resulted in another period of extreme cold. This episode will also serve as the location for additional extreme cold highlights from June 16 through the morning of the 19th.