High Wind — Upper Blackfoot and Macdonald Pass, Montana

2025-12-17 · Upper Blackfoot and Macdonald Pass, Montana

Event narrative

Two MDT sensors (Flesher Pass and MacDonald Pass) and a NW Energy sensor (002NW Hwy 12 measured gusts in excess of 58 mph, including a peak gust of 78 mph at Flesher Pass. The sensor at MacDonald Pass measured sustained winds of 44 mph between 1145 AM and 715PM. At the NW energy sensor Hwy 12, sustained winds averaged 40 mph between 320 PM and 420 PM. Finally, a public report was received stating 26 trees were blown down across Stemple Pass Rd 10 miles ESE of Lincoln.

Wider weather episode

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.

Source: NOAA Storm Events Database, event_id 1306391. Narrative written by the NWS forecast office that issued the report.