High Wind in Southern High Plains, Montana

Numerous sensors in this zone measured sustained winds averaged over at least an hour of 50 mph, or gusts in excess of 75 mph. These sensors include mesonet stations MTM49 7 NE Choteau, DELMT Dellwo, MTCTS Choteau South US-287 (MT DOT), MTPND Pendroy (MT DOT), RICMT Rice Ridge, MCBMT McBranty, TRFM Teton River Agrimet, HODMT Hodgkiss, DAHMT Dahlman, GOLMT Gollehan, and MTBOW Bowmans Corner (MT DOT), AWOS stations K1GM Golf and K1FM Foxtrot, Montana mesonet stations Bynum W, Augusta N, and Bowmans Corner. A co-op observer near Bynum reported roof damage and mailboxes being blown away. The peak gust observed was 104 mph at Bynum W Montana mesonet. Sustained winds at Bynum W averaged 74 mph between 1250 PM and 150 PM MST.

Robust low to mid level flow westerly flow associated with a potent shortwave and attendant cold fronts resulted in a prolonged period of high-end winds and gusts across the entire region Dec 17 into the 18th. Multiple gusts in excess of 90 mph were observed in populated areas, with a peak observed gust of 104 mph west of Bynum. Prolonged power outages were observed across the region, mostly due to trees being damaged/falling over completely. Additional societal impacts included extremely difficult to impossible travel conditions, which prompted a Civil Emergency Message for areas along the Rocky Mountain Front the afternoon of the 17th.