RENO, Nev. — A massive winter storm that could be the biggest to slam the region in more than a decade prompted the evacuation of hundreds of homes in northern Nevada and triggered flooding and mudslides that blocked major highways and stranded motorists in Northern California.

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 today. Forecasters warned a second storm is expected to hit the already drenched area tonight.

In Nevada, emergency officials voluntarily evacuated a total of 400 homes affecting about 1,300 residents in a south Reno neighborhood Sunday afternoon as the Truckee River began to leave its banks and drainage ditches started to overflow south of U.S. Interstate 80.

This is a serious flood situation,” the National Weather Service said in a special flood statement late Sunday night. Flood warnings continue along much of the Sierra’s eastern front and western Nevada into Tuesday

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 neighboring Sparks, where the worst flooding is expected to send several feet of water early Monday into an industrial area where 25,000 people work.