High Wind in Hill County, Montana

Numerous sensors in Hill County measured sustained winds of 40 mph or greater averaged over at least an hour or gusts of 58 mph or greater, including mesonet sensors EW1937 Goldstone, GW3530 Rudyard 11 S, GW4079 Inverness 10 SSE, MTINV Inverness (MT DOT), EW1931 Rudyard, FW1664 Hingham, MTM06 ARC N Havre, GW6391 Gildford 10 N, GW6390 Gildford 6 SE, and GW6392 Gildford 15 N, ASOS station KHVR Havre Airport, and Montana mesonet stations Fox Crossing SW, Lake Thibadeau W, Simpson, Kremlin NW, Inverness S, and Inverness N. The peak gust of 79 mph was observed at Fox Crossing. Some stations lost power through the event, so the peak gust may have been stronger. Sustained winds at Fox Crossing averaged 59 mph over an hour between 345 and 445 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.