* Southern California slammed by strongest storms in years
* Nearly 800 homes evacuated in foothills around L.A.
* Authorities fear mudslides in areas left barren by fires (Recasts with storms called strongest to hit area in years, updates number of evacuations, other details)
By Steve Gorman and Dan Whitcomb
LOS ANGELES, Jan 20 (Reuters) - Authorities ordered the evacuation of nearly 800 homes in the foothills near Los Angeles on Wednesday, fearing that the strongest storms to hit Southern California in years would touch off mudslides.
The threatened homes lie in suburbs north of Los Angeles, nestled against steep hillsides and canyons left barren by a massive wildfire last summer and saturated by heavy rain over the past three days.
The storms, which began punishing Southern California on Sunday, were the heaviest to strike the region since at least 2005, National Weather Service specialist Bonnie Bartling said.
Sheriff’s deputies said most residents in slide-threatened areas were leaving as crews piled up sandbags on streets and used bulldozers to clear mud and boulders that filled debris basins designed to catch runoff from canyons.
Others were determined to stay, having signed waiver forms with Los Angeles County.
Delos Tucker, a 78-year-old retired geologist who has lived in the hills of La Canada-Flintridge since 1962, said his house is probably out of harm’s way because it is several feet above street level.
“But everybody including my son ... has been calling me and telling me to get my ass out,” he said with a chuckle.
Likewise, neighbor Jack Wunderlich, 77, said the fact that his wife was bedridden factored into his decision to stay put. Otherwise, he said, “It’s like moving a hospital.”
Sheriff’s deputy Edwin Roberts warned that it may be too late for residents to change their minds if the rain-soaked hillsides give way, unleashing torrents of earth and water.
“Let’s say it does start coming down, and they decide to leave — they’re not going to be able to. Six inches of water can take you off your feet on this type of incline,” he said.
Utility company Southern California Edison said it was working to restore power to more than 11,000 customers whose electricity was knocked out by Tuesday’s storm. Another 12,000 homes and business were without power in the Sacramento area.
The storm spawned thunder, lightning and hail across several counties and dumped snow in the mountains, forcing closure of California’s chief north-south highway, Interstate 5, at the Tejon Pass.
A winter storm warning was posted for higher elevations, with snow accumulations of up to 4 feet (1.2 metres) and near-blizzard conditions in some mountains.
Flooding shut down numerous roads in low-lying areas.
Wednesday’s storm was the strongest of the three so far, with gale-force winds and up to 5 inches (13 cm) of rainfall, according to the National Weather Service.
Authorities blamed two deaths on the storms, including a 21-year-old man crushed in his sleep on Monday when a huge tree toppled onto his home. They closed several piers and shut down beachfront access in some areas because of heavy surf.
On Tuesday, the weather service issued tornado warnings for parts of Los Angeles and Orange County, a rare development for normally sunny Southern California that prompted several schools to keep students indoors until the threat passed.
The Weather Service confirmed that at least one tornado had briefly touched down in Orange County, and witnesses reported spotting several waterspouts.
A fourth storm was expected to hit the area on Thursday.
Editing by Cynthia Osterman