UPDATE: A High Wind Warning is now active across parts of north-central Montana today, with gusts to 65 mph expected between 11 AM and 3 PM. Separately, NWS Missoula is tracking the same Wednesday–Friday system and warns of a 30-degree temperature plunge from Tuesday's highs, with snow levels crashing to 4,500 feet by Thursday morning — lower than originally outlined — and accumulations possible along mountain passes of the Continental Divide in western Montana. The Watch-to-Warning upgrade flagged below remains pending; check NWS Great Falls for the latest forecast.
A Winter Storm Warning for central and southwestern Montana is probably coming before the storm hits Wednesday evening, with forecasters in the National Weather Service office in Great Falls signaling a likely upgrade as the system approaches. The current Winter Storm Watch remains in effect for the high mountain zones, alongside a Winter Weather Advisory covering West Yellowstone and the tri-border area with Idaho and Wyoming.
The system is expected to bring up to 10 inches of heavy wet snow to higher elevations from the Little Belt Mountains through the Gallatin Range, along with wind gusts reaching 60 mph. Temperatures are forecast to drop sharply, running roughly 25 degrees below mid-April averages. The Watch runs from 6 PM MDT Wednesday through 6 PM MDT Thursday for the high mountain zones, with Judith Basin, Fergus County below 4,500 feet, and the Snowy and Judith Mountains added from midnight Wednesday.
Rain To Snow Transition Raises ConcernThe storm is expected to arrive Wednesday afternoon initially as rain, before rapidly transitioning to snow as colder air moves in during the evening hours. That shift is expected to create hazardous travel conditions overnight into Thursday, particularly as wet surfaces freeze and blowing snow reduces visibility.
Forecasters warn that visibility could drop below a quarter mile at times, with the combination of heavy snow and wind increasing the risk of downed trees and power lines. Isolated outages across central Montana are possible.
Bozeman Pass And I-90 Expected To See Significant ImpactsInterstate 90 over Bozeman Pass, at 5,712 feet, is expected to be one of the most heavily affected travel corridors. The route, a key east to west freight artery connecting the Pacific Northwest and the Midwest, could see rapidly deteriorating conditions Wednesday night into early Thursday.
US-191 between Bozeman and West Yellowstone is also expected to be impacted, affecting access to Yellowstone National Park, whose West Entrance sits inside the Advisory area. The park's roads opened for the spring season only days ago. Higher elevation passes across the region may require chain restrictions depending on conditions.
Broader Impacts Across Ranch And Fire RegionsIn addition to travel disruptions, the storm arrives during calving season in parts of central Montana, raising concerns for ranching operations in Judith Basin and Fergus counties.
Meanwhile, just across the state line in Wyoming's Bighorn Basin, dry and windy conditions associated with the same weather system have prompted a Fire Weather Watch, highlighting sharply contrasting impacts across the region.
Timing And OutlookThe heaviest snowfall is expected late Wednesday night through Thursday, with conditions gradually easing by Friday. Updated advisories and warnings will be issued as the system approaches.