Heavy rain and snow will begin to ease on Thursday in the western U.S., where swollen rivers are expected to recede, forecasters said, after flooding that has forced thousands to evacuate in recent days.


A foot of snow and possible rain showers were expected during the day in parts of the region before tapering off by Friday, the National Weather Service said.


"The pattern will begin to change along the West Coast over the next couple days as the string of Pacific storm systems comes to and end and drier conditions prevail," it said.


A weather pattern meteorologists call an "atmospheric river" — a dense plume of moisture flowing from the tropical Pacific and into California and the West — has brought heavy snows and rains to the region over the last few weeks.


The latest round of extreme precipitation forced thousands of residents in small North California communities to seek higher ground in recent days.


Residents in Wilton, a community of more than 5,000 people near California's state capital, were advised to evacuate their homes because of anticipated flooding along the Cosumnes River.

In wine-growing Sonoma County, north of San Francisco, authorities asked residents of 650 homes in Guerneville, California, to evacuate as the Russian River has flooded parts of the community of less than 5,000 people.

The river at Guerneville peaked at 37.8 feet early Wednesday evening, nearly 6 feet above flood stage, before it began to recede. It is expected to fall back below flood stage around noon local time on Thursday, the weather service said.

In Nevada, authorities on social media advised residents to remain vigilant to the threat of flooding after the Truckee River, which runs through Reno, overflowed its banks earlier this week.

To the north, schools in Portland, Oregon, remained closed on Thursday as the city of more than 600,000 digs out from a blizzard that delivered roughly a foot of snow.

About 6,700 customers of a local utility company remained without power early on Thursday in the Portland area after the storm knocked out electricity for more than 63,000 customers, the utility said.

Ski resorts and roads in the Sierra Nevada mountains also remained closed on Thursday after more than 10 feet of snow fell in parts of the area over the last week, according to the National Weather Service.

(Reporting by Brendan O'Brien in Milwaukee; Editing by Hugh Lawson)