The National Weather Service office in Great Falls issued a High Wind Warning for the Big Belt, Bridger, and Castle Mountains on June 16, with the warning running from noon through midnight that evening. The agency rated the event as severe in intensity with expected urgency, meaning forecasters were confident in the timing and strength of the system.
Forecasters called for westerly winds of 25 to 35 mph sustained, with gusts reaching up to 60 mph in the affected mountain zones. Those figures put conditions in the range that can bring down tree limbs, create hazardous driving for high-profile vehicles, and trigger isolated power outages across the affected terrain.
For Helena-area residents, the Big Belt Mountains east of town are a popular summer destination for hiking, fishing the Beaver Creek drainage, and dispersed camping. FWP and Forest Service roads into those areas can become dangerous quickly in high-wind conditions, particularly for trailers and campers. Anyone with plans in those ranges was advised to check conditions before heading out and to be prepared to turn back if gusts picked up.