Hundreds of vehicles were stuck on the 710 Freeway in Long Beach this afternoon in rain-caused floods, authorities said. Firefighters responded this afternoon to the 710 Freeway between Ocean Boulevard and 6th Street, said Long Beach Fire Department Battalion Chief Frank Hayes, attempting to remove hundreds of vehicles that were floating in standing water. Other rain-related flooding was reported throughout Long Beach, Hayes said, including several intersections that were blocked with floating vehicles.

Flooding and loose boats were reported throughout Sunset Beach and Huntington Harbor, he said. A KCAL television news report showed footage of a sport-utility vehicle that flipped over in Sunset Beach by the storm.

Sheriff’s deputies were responding to reports that a tornado or waterspout had touched down near Anderson Street and Pacific Coast Highway, lifting several catamarans 30 feet to 50 feet in the air, according to Orange County Sheriff’s Department spokesman Jim Amormino.

Witnesses reported seeing a tornado touch down in Sunset Beach this afternoon and lift boats out of the water as it came onshore, sheriff’s officials said.

A new storm with tornado-like strength pounded the Southern California coast this afternoon, flipping a car, causing major street flooding, damaging homes and stranding motorists.

The Los Angeles Police Department has called a tactical alert and is evacuating homes in San Pedro. The department has also shutdown an area between Pacific and Gaffey and 4th and 7th streets hit by the worst of the flood. Officials say a lightning strike hit the Conoco refinery, causing a small fire.

The National Weather Service has canceled a tornado warning for Los Angeles County, but a warning remains for Orange County.

Officials are assessing the damage from the storm, which slammed into the coast. Major street flooding was reported in San Pedro and Long Beach.

In Huntington Beach, the beaches were mostly empty while waves surged, lightning struck and wind reached gusts of 52 miles per hour. The gusts topped 72 mph in Newport Beach.

The storm was accompanied by rain, lightning, hail, ice and high waves. Officials are worried about mudslides in burn areas in L.A. and Orange counties as the new storm hit the mountain areas.

Piers along the Southern California coast were being closed today as huge waves surged onto beaches and harbors with a rainstorm that is expected to bring wind, thunder and lightning.

Ventura police closed the city's nearly 2,000-foot wooden pier this morning as a precaution; no damage was reported. But huge waves crashed near beachfront homes. "We're expecting some pretty big surf," said Sgt. Jack Richards.

Lifeguards also closed the Hermosa Beach Pier and were in the process of closing the Manhattan Beach pier, according to Los Angeles County lifeguards.

The National Weather Service issued an urban and small stream flood advisory for Los Angeles and Ventura counties.

A high surf advisory is in effect through Friday and the National Weather Service has issued a coastal flood watch starting tonight through late Wednesday, saying very large surf combined with strong wind is expected to push water into low-lying areas during high tide.

The largest waves will appear Wednesday and Thursday, when breakers could reach as high as 25 feet.

"The surf is very large," said Capt. Mike Patterson of the Los Angeles County Fire Department's Lifeguard Division, overlooking 15-foot waves at the Hermosa Beach pier, where gates were locked this morning. "It's another facet of the weather."

A second in a series of four storms is sweeping across Southern California today, prompting power outages and fears of mud flows in hillsides stripped of vegetation because of recent wildfires.

Rain should turn into heavy showers with thunder, lightning and gusty winds by this afternoon and evening, dumping between ¾ and 1 ½ inches, according to forecasters. The storm could bring hail and weak, isolated tornadoes inland and off the coast.

"It's a fast mover with gusty winds behind it, so it should be out of the area before midnight," said Stuart Seto, a weather specialist with the National Weather Service in Oxnard. Authorities are urging caution during the afternoon commute, when the brunt of today's storm is expected to hit. They are also warning people to stay inside during the lightning and thunder.

"If you hear it roar, go indoors," Seto said.

-- Paloma Esquivel in Orange County, Cathleen Decker and Ruben Vives in Long Beach, Andrew Blankstein and Tony Barboza in Los Angeles

More breaking news in L.A. Now:

San Diego mayor cites 'prejudice' in earlier opposition to gay marriage

Man ordered to stand trial in Ryan Seacrest stalking case

Proposal to build 13-story tower next to the Grove raises traffic concerns

San Onofre siren wakes nearby residents, turns out to be false alarm

Schwarzenegger's effort to release 40,000 prisoners put on hold by Supreme Court

Second storm moving into Southern California could bring mudflows, more power outages

L.A. City Council gives preliminary approval to pot ordinance requiring 1,000-foot buffer zones