Storm Advances on Southland

Heavy surf pounded the coast from San Luis Obispo to the Mexican border Tuesday as an intense winter storm approached the coast of Southern California.

Waves that are expected to build over the next couple of days eroded oceanfront sand and flooded the garages of more than 20 waterfront homes in Seal Beach on Tuesday morning. Seawater, rocks and mud surged through beachfront campsites in Ventura County, forcing the evacuation of several visitors.

Meteorologists said gale-force winds are circling the storm, which is expected to dump heavy rain on the Los Angeles area tonight, Thursday and Friday.

“This storm is big, it’s powerful and it’s coming straight at us,” said Tim McClung, a meteorologist who works as the warning coordinator at the National Weather Service office in Oxnard. “We’ll be getting the full brunt of it.”

The normally cautious Weather Service said the probability of rain tonight and Thursday is “100%.” Forecasters said as much as 3 inches could fall on coastal cities, with up to twice that much in foothill communities.

Runoff is expected to pool in low-lying areas, but the main threat will come from the sea, McClung said.

“With the full moon, the tides are high, and the storm could generate waves as tall as 20 feet,” he said. “There’s a real danger of coastal flooding.”

There could be trouble at higher elevations, too, forecasters said. A winter storm watch was issued for the San Gabriel, San Bernardino and Tehachapi mountains, where forecasters said as much as 16 inches of snow could fall above 4,000 feet.

The storm is expected to taper off Friday afternoon, but forecasters said there is a possibility of additional rain and snow by Sunday.

Most of Tuesday’s flooding occurred in the gated community of Surfside in Seal Beach.

Water began to pour into an alley behind the garages that flooded shortly after 8 a.m., when 8-foot waves, riding a high tide, broke through a 4-foot-tall wall of sand that had been bulldozed into place last weekend in an effort to prevent flooding.

Calf-deep water slowed traffic to a crawl on Pacific Coast Highway at Anderson Street.

Work crews rebuilt the sand wall to a height of 10 feet in Surfside, and Steve Badum, Seal Beach’s director of public works, expressed optimism that the berm was tall and strong enough to hold back higher surf as the storm moves onshore.

“This is only the beginning, dude, only the beginning,” said homeowner Mike Donovan, 53.

Major flooding last occurred in Seal Beach in 1983, when El Nino meteorological conditions contributed to a series of heavy storms, Badum said.

“It’s kind of the price you pay” for living in a beachfront home, he said. “You have to take the good with the bad.”

In Ventura County, officials at Emma Wood Beach said the campgrounds there would remain closed until crews can clean up the damage caused by Tuesday’s invasive surf. With more damage expected tonight and Thursday, the work probably won’t begin until the storm is over.

In the foothills above Thousand Oaks, residents braced for possible mudslides during the storm on slopes denuded last month by wildfires.

Mark Towne, a coordinator with the Conejo Open Space Conservation Agency, said work crews have been filling sand bags around flood channels and storm drains to prevent an overflow of loose hillside debris. In recent days, he said, crews have filled nearly 1,000 sandbags.

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Times staff writer Timothy Hughes and correspondent Laura Wides contributed to this story.

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Pacific Heights

Forecasters are predicting high surf over the next three days because of a storm that was approaching Southern California on Tuesday. Wave sensors attached to the Harvest oil platform near Point Conception, along with other offshore weather buoys, help Scripps Institution of Oceanography in La Jolla provide three-day wave forecasts. Exceptionally high tides accompanying the large swell could trigger coastal flooding.