Southland Is Buffeted by High Winds : Weather: Orange County reports a brush fire, power outages and mostly minor freeway problems.

Gusty Santa Ana winds whipped through Southern California on Wednesday, downing power lines, creating airborne traffic hazards and sparking at least two fires.

As winds reached 60 m.p.h. early in the morning, 13 power poles snapped in the northeast San Fernando Valley, according to the Los Angeles Department of Water and Power. About 4,000 customers in Sylmar and Pacoima were left without electricity.

While homeowners dealt with loosened roof shingles and tiles and rattling windows, commuters from the San Fernando Valley to Orange County dodged flying palm fronds, fallen tree limbs and tumbleweeds that bounced in the air like jugglers’ balls.

In Malibu, the Los Angeles County Fire Department reported that a five-acre blaze started when a car crashed into a telephone pole in Malibu Canyon and torched nearby brush. And in the Saddleback Mountain area of Orange County, a wind-fanned brush fire briefly caused anxiety but was contained after scorching just four acres, officials said.

A utility pole downed by wind near Pacific Coast Highway in Malibu left 145 customers, including parts of Pepperdine University, without power for two hours, a spokesman for Southern California Edison Co. said. In Orange County, more than 7,000 customers had service interrupted, mainly in Costa Mesa and Santa Ana. Several people were stranded in a Costa Mesa City Hall elevator for about an hour, officials said.

Wind blew down fencing along the center divider in several sections of Interstate 15 in Riverside County, the California Highway Patrol reported, but traffic was not impeded. Waves of wind-borne dust and debris slowed motorists to 5 m.p.h. in some sections of Interstate 10 between Ontario and San Bernardino.

“We’re advising extreme caution,” CHP spokesman Mark Mezzano said.

The CHP issued travel warnings for campers and trailers throughout the Inland Empire and on all freeways north of California 118 to the Grapevine, including the Antelope Valley.

The wind played a practical joke on some Orange County motorists Wednesday morning, causing them to believe that part of the Santa Ana Freeway was closed, the CHP said. The wind blew off a canvas flap on a sign about an upcoming temporary closure near the El Toro Y interchange. Motorists seeing the sign made a detour onto the San Diego Freeway, intensifying the usual bottlenecks on that freeway.

On Norris Street in Pacoima, two unoccupied cars were crushed under an uprooted tree, breaking windows and flattening tires.

Carmen Rojas, whose two sons own the vehicles, heard “a loud popping noise” about 4 a.m. “I thought a bomb had gone off,” she said.

In Pasadena, a worker at the Rose City Diner lost a Christmas decoration, a nine-foot papier-mache Nutcracker-style soldier, that he was removing from the building.

“The wind just took it down the street” like tissue paper, owner Sal Casola said.

Winds of 20 to 40 m.p.h. were expected to continue today, with gusts “pretty common around 50 m.p.h.,” said Marty McKewon, a meteorologist with WeatherData Inc., which provides forecasts for The Times. “But . . . I think we’ll see a decrease in the afternoon.”

The National Weather Service said the winds were being caused by a high-pressure center stalled over Idaho and Nevada. Santa Ana winds tend to be most intense along mountain ridges and through passes, McKewon said.

“There can be great differences across the area,” he added. “At times today, the (Los Angeles) Civic Center had only up to 10-m.p.h. wind gusts, while Santa Ana had 50 m.p.h.”

Wednesday’s Civic Center high reached 74 degrees. Today will be slightly warmer, with highs in the middle to upper 70s, forecasters said.

In Orange County, the CHP reported a variety of traffic woes stemming from the winds, which a spokeswoman said blew up to 60 m.p.h. in some canyon and inland areas. Winds elsewhere in the county ranged from 30 to 45 m.p.h., according to WeatherData.

“There were a lot of problems with things being blown on the freeways, but no fatalities and as far as I know no serious vehicle accidents--mostly fender benders,” said California Highway Patrol Officer Linda Burrus.

Giant tumbleweeds rolled out onto several freeways, frightening motorists and causing traffic to slow, stop or divert.

One Irvine woman, who asked not to be identified, said she was driving to work on the San Diego Freeway near the Costa Mesa Freeway, “and this man-sized tumbleweed came at my car. I slowed down, and so did other cars, and it was a miracle nobody got rear-ended.”

Breaking free and rolling are “how tumbleweeds do their reseeding,” said Deputy Orange County Agriculture Commissioner Bill Miller. “We have tumbleweeds scattered in various parts of Orange County. They even grow in urban areas, but they’re usually a bigger problem in places such as Riverside and San Bernardino counties.”

Orange County Fire Department Capt. Dan Young said the fire in the Saddleback Mountain area occurred at 2:04 p.m. but was quickly contained in the Bedford Canyon-Main Divide area.

Fire stations throughout the county were placed on alert in the event that the county’s parched hillsides should ignite during the Santa Anas. Young said the hot winds quickly dried up ground moisture from the recent rains.

“We’re at a level (for fire alert) that we haven’t been at since August. We get a couple of days of rain, and then the Santa Anas set in, and we’re right back the way we were in the summer,” Young added.

Elsewhere in South Orange County, a 20-foot eucalyptus tree fell across the on-ramp of Interstate 5 at Oso Parkway, prompting the CHP to issue a SigAlert. A motorist jumped out of his car, pulled out a chain saw and assisted officers in removing the tree, the CHP said.

Several blocks surrounding Costa Mesa City Hall, including the Police Department, lost electricity and telephone service when two utility poles went down and crashed atop a car in a parking lot near Bristol and Bear streets. The outage also left several people stranded in a City Hall elevator for about an hour, but no one was hurt, police said.

Sheriff’s deputies and local police reported scores of false alarms. Alarms were set off when the wind shook plate-glass windows, Sheriff’s Lt. Richard J. Olson said.

Times staff writers James M. Gomez in Orange County, Julio Moran in Los Angeles, Joanna Miller in Ventura County and Jenifer Warren in Riverside County contributed to this story.