High Wind in Southern Lewis and Clark, Montana

Estimated 66 kt (76 mph) non-thunderstorm wind gust reported at 18 SW Augusta.

The onset of a high impact wind event began on Tuesday January 13th, 2020, when a typical brand of strong winds descended over the normally wind prone Rocky Mountain Front and adjoining areas. Widespread anomalously strong winds then swept through much of Montana on the following day as a vigorous Pacific weather system and its associated 70 to 100 kt 700 mb jet max moved east through the Northern Rockies into the plains. A Pacific cold frontal passage helped transfer these winds to the surface and cold air advection on the sub-sident side of the trough maintained higher winds speeds for much of the day. Great Falls (76 mph), Helena (80 mph), and Havre (78 mph) all set wind wind speed records for the month of January. The winds were not only abnormally strong but they persisted longer than what is normally experienced, with some locations seeing frequent severe wind gusts for six hours or more. The impacts were felt throughout North-central and Southwest Montana and included, road closures due to areas of dense blowing dust, semi trailer roll overs, power outages, property damage, and even a few grass fires.