San Diego Sheriff's Lt. Mike Munsey said the woman was killed when a eucalyptus tree with a 10-foot diameter trunk crushed her trailer and a neighbor's in a mobile home park near El Cajon. Emergency crews needed a crane to move the tree and extricate her body from the wreckage of her home.
Los Angeles County fire officials said they would issue mandatory evacuation orders for about 587 homes in flood-prone foothill areas beginning early Wednesday in anticipation of the next storm.
Forecasters said thunderstorms and what looked like tornados surged ashore with fierce winds in Santa Barbara, Los Angeles County beach towns and areas of Orange and San Diego counties.
In San Pedro, a working class neighborhood near the Port of Los Angeles, several blocks were flooded with about six feet of water when storm drains clogged with debris.
Jerry Bazan spent the afternoon sweeping several inches of water out of his living room, where toys, sodden clothing and furniture were strewn about and a thick layer of mud coated the floor.
Bazan said the water rose to about two feet in his apartment within a matter of minutes and some of it was contaminated with sewage. Outside, the water lifted a Dodge Ram truck and carried it down the street, he said.
"It was a heavy downpour, and the drainage system was clogged," he said. "There was nowhere for the water to go, and it just rose up."
Police said 16 people were displaced from flooded homes in the San Pedro area.
Kimmara Acosta, 51, a saleswoman at Castle Tile in Costa Mesa, was sitting at her desk when she saw palm trees outside blowing horizontally.
"The wind kind of whipped through the parking lot, and the window blew in," she said, still breathless a half-hour later. "It was like an explosion. My mind said 'earthquake!' and I ducked under the desk."
The wind threw shards of glass across the room, but tile displays and the desk protected Acosta. No one was hurt.
High winds flipped a parked SUV onto its side and blew out windows in Seal Beach, but forecasters need to examine the damage and interview witnesses before they can confirm that a tornado swept through.
Santa Barbara fire officials said what looked like a small tornado cut a path of damage across a residential neighborhood of Goleta, uprooting trees, tearing shingles off a roof and breaking a hole in a fence.
Unlike twisters in the Midwest that can run for miles on the ground, Southern California tornadoes tend to start as waterspouts and dissipate quickly when they come ashore, said Philip Gonsalves, a National Weather Service meteorologist in San Diego.
The fast-moving band of thunderstorms moved on in minutes, leaving spotty sunshine as it headed into Riverside and San Bernardino counties. It left some streets underwater in low-lying beach communities and turned other roadways into muddy swamps. Televised reports showed parked cars with water up to the hoods and kayakers paddling through the streets of Long Beach.
Southbound Interstate 710 flooded south of Interstate 405, trapping about a dozen vehicles in water and closing the freeway for hours, Long Beach fire spokesman Joshua Johnson said.
In inland San Bernardino County, two boys, ages 10 and 12, were rescued from the racing waters in a swollen flood-control channel in Montclair.
Firefighters used a ladder to help them up, said Inspector Steve Zermeno of the Los Angeles County Fire Department.
"The water's moving pretty fast," he said. "They're lucky someone spotted them when they did."
Flash flood watches remained for areas of Santa Barbara, Ventura and Los Angeles counties where wildfires in 2008 and last year stripped hillsides down to bare, black earth.
The chance of mudslides and flooding -- a worry after every rainstorm -- intensified after a downpour Monday dumped 2 to 5 inches of rain in the mountains and left catch basins choked with debris.
In the foothills of La Canada Flintridge, just north of Los Angeles, residents looked on warily as County Public Works crews used bulldozers and shovels to move mud out of cul-de-sacs. Fist-sized rocks were strewn across a winding, canyon road where water rushed through gutters.
One homeowner, Gary Stibel, had lined his backyard with sandbags a couple of feet high and had covered part of the hillside behind his home with plastic tarp place to divert the floodwater. So far, it was keeping out rocks and debris, but Stibel, whose home was threatened by one of last year's wildfires, said he knew he wasn't out of the woods.
"The ground is really saturated right now from the two storms we had come through yesterday and today, so I'm really concerned," he said as he surveyed his work. As he spoke, it started to rain again.
"Shoot! The fog is coming in too," he said, gazing off toward the downtown Los Angeles skyline.
A strong jet stream was sending the line of storms ashore from the Pacific Ocean, with the wet weather expected to continue through Thursday.
In San Jose, three people rescued a man from a burning car when it spun out on a rain-soaked road and hit a crosswalk sign. The rescuers used a knife to cut the man loose from his seat belt, then pulled him to safety just seconds before the car burst into flames, authorities said.
The man's condition was not immediately known.
Interstate 5, a main state highway, was closed in Redding due to a downed line. Highway 70 near the border of Butte and Plumas counties remained closed after a rock slid onto the roadway Monday. The rock must be blasted apart to clear the roadway.