High Wind in Gallatin and Madison County Mountains and Centennial Mountains, Montana

Multiple sensors in this zone measured strong winds and gusts at lower elevations (Not at the high peaks), including MTBSK Big Sky Road (MT DOT), RAWS stations RRDM8 Red Rock and BTKM8 Burnt Creek, and NW Energy sensors Cornucopia Rd near Virginia City. The peak observed gust was at Cornucopia Rd and was 76 mph.

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.