Hours of heavy rain fell Thursday on saturated Southern California as the fourth Pacific storm in a week came ashore, triggering dire warnings by authorities that huge mud flows were likely in foothill communities and residents of endangered homes should obey evacuation orders.
A young man was rescued from a rushing river in Orange County, but rescuers said they can't confirm his report that a companion got swept away following a fruitless search. And a motorist was rescued after a tornado knocked power lines onto a highway in the state's remote southeast corner, trapping the man inside his vehicle.
Travel snarls mounted as major highways were closed by snow and tornado damage, and strong winds grounded flights at several airports. Another tornado left a trail of damage in a community northwest of Los Angeles.
The siege of storms has led to several deaths statewide and street flooding in urban areas, and has turned the region's often-dry river and creek channels into raging torrents.
Muddy water gushed down hills but there were no immediate major incidents, and officials appeared concerned the lack of massive debris flows from wildfire burn areas was misleading for residents.
Los Angeles County Fire Department Chief Deputy John Tripp bluntly warned at the outset of the storm that significant debris flows were likely and probably would block potential rescue attempts.
"For those people that are still in the homes and are in those areas of threat, it's very likely we will not be able to reach you," he said.
By nightfall, the storm's main rainfall was passing but forecasts warned of volatile conditions through the night. Los Angeles Mayor Antonio Villaraigosa said the city's evacuation orders remained in effect.
"While the worst of the last few storms is behind us, there still is a significant threat from thundershowers that are forming off the coast and have the potential to bring lightning, hail, waterspouts and small tornados," he said.
In the upper reaches of suburban La Canada Flintridge, where mountainsides rise sharply from the backyards of homes, authorities put pink ribbons on the mailboxes of residents who stayed behind so they would know where to search in the event of a catastrophe.
One person who stayed was Delos Tucker, a retired geologist who has lived in the community since the homes were built in 1962.
"I'm just gambling it's not going to happen," he said. "Let's hope I'm right."
As an overnight lull gave way to more rain at midmorning, public works crews shoveled mud from yards, driveways and gutters along Ocean View Boulevard in suburban La Canada Flintridge. The neighborhood was otherwise all but deserted, with newspaper and mail deliveries cut off.
The county's extensive flood-control system was working, but many of the basins designed to catch debris-laden runoff from fire-scarred mountains were full and evacuations remained necessary, said Gail Farber, the Los Angeles County Public Works director.
The basins are located on streams and other water courses emerging from the mountains to intercept surges of mud, boulders and other debris while allowing water to flow into open channels and underground storm drains that empty into the ocean.
The new storm system shut down Interstate 5 in the snowy Tehachapi Mountains north of Los Angeles for the second day in a row. And the California Highway Patrol closed part of Interstate 80 in the Sierra Nevada after about a dozen cars and trucks crashed in a heavy snowstorm.
In Orange County, firefighters pulled a 14-year-old boy from the swollen Santa Ana River, but an 11-mile search failed to find a companion the rescued boy said was also in the water. Orange Fire Department Capt. Ed Engler the search was called off by evening after efforts to spot the youth from bridges and helicopters.
A tornado rampaging across desert highways near the Arizona state line toppled high-voltage power poles that trapped a motorist in a vehicle on State Route 78, said Terri Kasinga, spokeswoman for the California Department of Transportation.
Lauren Bartlett, a spokeswoman for Southern California Edison, said the motorist drove through the wires and his vehicle got tangled in the lines. Crews cut off the electricity to the wires, allowing firefighters to rescue the driver. It was unclear if he was injured.
The tornado also toppled three big-rigs on Interstate 10 and more power lines on U.S. 95. The I-10 reopened late Thursday afternoon, but the other highways were likely to remain blocked for two days.
A fierce wind struck two neighborhoods in Ventura, and witnesses described a tornado, police Sgt. Jack Richards said. Trees were toppled, cars were damaged and a shed was torn apart in a 1 1/2-mile span through two neighborhoods. No one was hurt.
National Weather Service meteorologist Eric Boldt visited the scene and confirmed it was a small tornado.
Southwest Airlines canceled hundreds of flights in Southern California and Arizona due to strong winds and heavy rains.
More than 30,000 Edison customers were without power, and repair crews were having trouble reaching equipment in desert and mountain areas because of snow. Another 4,100 outages were reported in Los Angeles.
Acting Gov. Jerry Brown declared a state of emergency in Los Angeles, Orange, Riverside, San Francisco and Siskiyou counties because of the statewide storm impacts.
By late afternoon the storm had added as much as 3.2 inches of rain to the 5 to 6 inches that fell earlier in the week across the fire-charred mountains of Los Angeles County.
Friday showers were expected to give way to a dry weekend.
The major area of concern has been foothill communities along the perimeter of the San Gabriel Mountains, where a summer wildfire denuded 250 square miles of steep slopes northeast of Los Angeles.
The number of homes under evacuation orders has grown to more than 1,200 since the beginning of the week. Estimates of compliance have ranged up to 75 percent in some jurisdictions but down to 50 percent elsewhere.
Two people have been killed by falling trees, and police in Newman were searching for the body of a man who tried to drive across a flooded road.
In San Jose, a man died after falling 30 feet from the side of a freeway after he got out of a car that spun out in the rain and then jumped out of the path of an out-of-control car.
In San Diego, the Border Patrol said three people were rescued and treated for hypothermia after being swept away while trying to cross the storm-swollen Tijuana River from Mexico.
California State University, Long Beach, remained closed after some buildings flooded Wednesday.
The weather also forced cancellation of horse racing at Santa Anita Park in Arcadia and postponement of the second round of the Bob Hope Classic golf tournament near Palm Springs.
Sea World in San Diego was also closed due to severe weather.
The stormy weather also delayed last Saturday's planned departure of 16-year-old sailor Abby Sunderland from Marina del Rey on her attempt to become the youngest person to circumnavigate the globe nonstop and without assistance. The Thousand Oaks girl now plans to leave Jan. 23.