Atmospheric river flooding slams Montana, washing out infrastructure ahead of midweek windstorm
A parade of atmospheric rivers and rapid snowmelt sent torrents of water into creeks and rivers across western Montana, destroying bridges and flooding homes. As recovery begins, more rain is expected early in the week, followed by a midweek windstorm with gusts up to 70 mph that could cause power outages.
As a river roared in Libby, Montana on Dec. 11, 2025 multiple parts of a bridge collapsed. The flooding damage was caused by Atmospheric River rains and snowmelt.
Roads and bridges in western Montana were wiped out by powerful flooding last week after some areas saw around half a foot of rain. Rapid snowmelt added to the runoff, sending water rushing into creeks and rivers.
Flash flooding in Lincoln County — including the towns of Libby and Troy — began late last week and destroyed about five bridges, including along Lauer Lane to Swede Mountain, and washed out multiple roads.
River flooding damage in Libby, Montana after heavy rainfall and rapid snowmelt on Dec. 11, 2025. (Image credit: Jordan LeCount)
On Dec. 11, Montana Gov. Greg Gianforte declared a flooding emergency in northwestern Montana.
“Continued rainfall across northwestern Montana has flooded some of our communities, including the town of Libby,” Gianforte said in a statement. “This order will ensure resources are deployed quickly and effectively to protect Montanans and their property.”
The video above shows a bridge south of Libby on Farm to Market Road that was destroyed by flooding. About a minute into the footage, a large section of roadway collapses into the rushing water.
River flooding damage in Libby, Montana after heavy rainfall and rapid snowmelt on Dec. 11, 2025. (Image credit: Jordan LeCount)
The Montana Free Press reports that homes in the area were surrounded by water, but the full scope of the damage is still being assessed.
As recovery gets underway, more rain is in the forecast early in the week. The same storm system that brought heavy rain and flooding to the Pacific Northwest will spread rain, snow and powerful winds across Montana Wednesday and Wednesday night. Wind gusts as high as 70 mph are possible across much of the state, with even stronger gusts up to 80 mph in higher terrain in northwestern Montana. The AccuWeather Local StormMax™ is 105 mph.
Strong winds forecast across the Northwest on Wednesday, Dec. 17, 2025.
Winds of this magnitude can down trees, damage structures and cause power outages. Travel may also be disrupted as dangerous crosswinds create difficult conditions for high-profile vehicles.
Snow will continue across the higher elevations into late week. Snow levels are forecast to drop through Thursday, briefly reaching some valley floors before rising again Thursday afternoon.
Report a Typo
