The National Weather Service out of Great Falls issued a Winter Storm Warning Saturday evening, October 10, covering the Big Belt, Bridger, and Castle Mountains through 6 a.m. Monday, October 12. Forecasters are calling for heavy, wet snow totaling 6 to 14 inches in those ranges, with wind gusts up to 40 mph.
A separate warning covering portions of central and north-central Montana carries higher totals — 10 to 20 inches across the broader area, with up to 7 inches expected in the Lincoln valley and isolated amounts approaching 30 inches within the Bob Marshall Wilderness. Wind gusts in that zone could reach 45 mph.
The wet, heavy nature of the snow is the detail forecasters keep flagging. That kind of snow loads onto tree branches fast, and the combination of weight and wind means downed branches and isolated power outages are possible through the weekend. Travel in the affected mountain areas could be very difficult, and anyone planning to move through those corridors before Monday morning should check road conditions with the Montana Department of Transportation before heading out.
For Helena itself, the city sits below the elevations under the Warning, but residents with family or travel plans headed into the mountains — or east and north through the affected ranges — should plan accordingly. The Warning expires at 6 a.m. Monday.