A drenching winter storm swelled rivers in northern California to their highest levels in seven years, causing power outages and forcing some residents to evacuate.

Flood warnings were in effect for the northern half of the state after the storm swept through Tuesday and Wednesday. One person was killed in a car crash caused by a mudslide.

"It's been several years since we've had this widespread of flooding, and we're not done," said Rob Hartman of the National Weather Service's California-Nevada River Forecast Center in Sacramento.

The last significant flooding in the region was during the El Nino year of 1998 and a year earlier, when three people died after levees collapsed north of Sacramento. The danger is lower this time because there is relatively little snow in the Sierra Nevada to be melted by the warm rains, officials said.

In Modesto, a mudslide led to a pileup that killed a motorist Monday. And in Mendocino County, four homes were evacuated after a landslide Tuesday night.

Rivers were cresting from the Napa County wine country to the far northern coast, including the Russian, Navarro, Scott, Klamath and Eel rivers. They were expected to rise to flood stage periodically through the weekend without causing severe damage.

"We're getting an early start on the rain-and-snow season, which is good as long as we don't get flooding," said Don Strickland, a spokesman for the state Department of Water Resources.

Federal and state water managers were releasing torrents of water at the Oroville and Folsom dams, but both reservoirs had plenty of capacity to handle additional runoff, officials said.

More storms were forecast for Friday through the New Year's weekend. The system was expected to spread farther south by Saturday and potentially cause mudslides and flash floods in recently burned areas of Southern California, Hartman said.