Powerful thunderstorms hammered already saturated Southern California (search) on Saturday with soaking rain and hail, flooding roads and homes, knocking out power to thousands of customers and raising the threat of mudslides.

La Conchita (search), the coastal hamlet where 10 people were killed by a huge landslide last month, was a ghost town after the U.S. Geological Survey (search) warned that none of the roughly 150 remaining homes could be considered safe.

In a year of record rainfall, the latest storms had soaked downtown Los Angeles with about 2 inches of rain since Thursday.

The area has seen nearly three times the average rainfall this season, and periodic showers are expected for several more days throughout the state.

"All of California's going to get a shot of rain in the next couple of days, but most of it will be from Santa Barbara south," said National Weather Service meteorologist Steve Anderson "That's the bull's-eye for the next two days."

The unsettled weather even produced two tornadoes that briefly touched down in San Diego and Riverside counties. Each lasted about two minutes, breaking windows, and knocking over trees and power lines. No injuries were reported.

"It's sort of a miniature version of what you might see in the Great Plains," said Steven Vanderburg, a National Weather Service forecaster in San Diego.

The storm knocked out power to thousands of customers in the area, according to Southern California Edison and the Los Angeles Department of Water and Power.

Rain may also have contributed to a highway crash Saturday that injured 10 people in the San Fernando Valley, where a bus carrying tourists rear-ended a sport utility vehicle on the Ventura Freeway.

The Red Cross opened an emergency shelter in Long Beach, where residents had to evacuate seven homes because of flooding, spokeswoman Margaret Madonna said.

Amtrak canceled Los Angeles-to-Santa Barbara commuter rail service from Friday night through Sunday afternoon because of mudslides in Moorpark.

Mudslides also threatened homes in Culver City, in Los Angeles County, and in the Orange County cities of Mission Viejo and Anaheim, authorities said.

During the early morning, authorities shut down a two-mile stretch of Interstate 5 for several hours through the City of Commerce, south of downtown Los Angeles, because it was flooded by a foot of water. Similar flooding was reported along the 710 Freeway in Long Beach.

The weekend storm was expected to dump up to 2 feet of snow at higher elevations of the Sierra Nevada, adding to an already impressive snowpack.