High Wind in Bears Paw Mountains and Southern Blaine, Montana

Numerous sensors in this zone measured sustained winds of 40 mph or greater averaged over at least an hour, or gusts of 58 mph or greater, including RAWS station FBLM8 Fort Belknap and LBCM8 Little Bullwhacker Creek, Montana mesonet stations Dry Lake, Cleveland N, Warrick S, and Big Sandy SE. An additional public report was received stating gusts similar to what these sensors observed. The peak observed gust in this zone was observed on the Fort Belknap reservation at the Fort Belknap RAWS (88 mph) between 618 PM and 718 PM.

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.