Thousands of people were evacuated on Wednesday across the northwest US state of Washington as flooding caused by heavy rain and melting snow threatened to deluge the region, officials and reports said.
After being blanketed by record snow in recent weeks, warmer temperatures and relentless rain led to severe flooding throughout the state, causing avalanches and mudslides and forcing several freeways to close.
Up to 30 centimeters of rain could fall across the Cascade and Olympic mountain ranges in the eastern and western parts of the state between Wednesday and Thursday, the office of state governor Chris Gregoire said in a statement.
"Major flooding is ongoing on eight to 10 rivers in western Washington, with record levels predicted for the Puyallup River near the town of Orting and Newaukum River near Chehalis," the statement said.
"Flood impacts have already forced the closure of some major highways, and could cause the closure of the I-5 in Lewis County."
Orting, a town of 6,000 people 60 kilometres south of Seattle, was reported to be severely at risk. Thousands of residents near Orting had already been ordered to evacuate, local television station KOMO reported, adding that 26,000 people throughout the region had fled their homes.
Eleven counties across the state were placed on flood alert on Wednesday, according to the National Weather Service.
Local television images of flooding near Shohomish County north of Seattle showed homes and cars underwater.
As many as 60 roads had been closed because of flooding since early Wednesday. Authorities also closed parts of the region's main north-south transit freeway.
"Closing a major freeway in such a highly populated, urban area is not something we take lightly," Washington State Patrol's Field Operations Bureau said in a statement. "Our priority is to close the freeway early enough that we don't put anyone in harm's way."
The Amtrak railway between Seattle and Portland, Oregon was also closed, The Seattle Times reported.
A Washington Department of Transportation statement said there were "significant avalanche concerns" in the state's three main mountain passes.