RENO, Nev. — More than 1,000 homes were evacuated in northern Nevada, and stranded motorists were pulled from cars stuck on flooded Northern California roads as thunderstorms arrived as part of a massive winter storm that could be the biggest to slam the region in more than a decade.

Crews in California cleared trees and debris Sunday following mudslides caused by steady rain accompanying the system that could dump 15 inches in the foothills of the Sierra and heavy snow on the mountain tops before it’s expected to move east early Monday.

Forecasters warned a second storm is expected to hit the already drenched area Monday night.

In Nevada, emergency officials voluntarily evacuated a total of 1,300 homes in a south Reno neighbourhood Sunday afternoon as the Truckee River began to leave its banks and drainage ditches started to overflow south of U.S. Interstate 80. No injuries had been reported, but high waters forced the closure of numerous area roads, a series of bridges in downtown Reno and a pair of Interstate 80 off-ramps in neighbouring Sparks, where the worst flooding is expected to send several feet of water early Monday into an industrial area where 25,000 people work.

Gov. Brian Sandoval – who declared a state of emergency on Saturday – told all non-essential state employees to stay home Monday. Bob Leighton, the Reno Fire Department’s chief of emergency operations, called it “a very dynamic situation that’s happening so fast it’s hard to keep up with the road closures.”

In Northern California, toppled trees on Sunday crashed against cars and homes or blocked roads in the San Francisco Bay area, and officials rescued stranded motorists from cars stuck on flooded roads on Sunday. A woman was killed Saturday by a falling tree while she took a walk on a San Francisco Bay Area golf course.

There were mudslides and flooding throughout Northern California that led to road closures, especially in the North Bay, one of the areas hardest hit and where the Napa River jumped its banks. Farther north, the U.S. 395 highway was temporarily closed in both directions in Mono County because of flooding.

Rangers at Yosemite National Park closed all roads leading to the park’s valley floor, a major attraction for visitors from around the world eager to view gushing waterfalls and gaze up at towering granite rock formations such as El Capitan and Half Dome. As of 11:56 a.m. on Jan. 8, reports KRON News, Yosemite remains closed, with the Merced River forecasted to go nearly four feet over its banks.

With file from Scott Sonner And Olga R. Rodriguez, THE ASSOCIATED PRESS