High Winds Snap O.C. Power Lines : Weather: 5,400 buildings in Huntington Beach left without power as gusts reach 65 m.p.h. Power goes out for 120,000 in Southland.

Chill winds with gusts of up to 65 m.p.h. raked Orange County on Thursday, snapping power lines and trees before leaving almost 7,000 homes and businesses without electricity in two coastal cities.

Hardest hit was Huntington Beach, where some 5,400 dwellings and buildings were left without power for several hours before work crews could make repairs to utility poles and broken wires.

Similarly, gale force winds caused havoc throughout Southern California, knocking out power to more than 120,000 people, fanning brush fires and shattering windows. At the Santa Monica Airport, a plane was overturned, and in Century City the facing from two high-rise buildings was torn off.

“The hardest hit areas were Castaic, Huntington Beach, Costa Mesa and Compton,” said Kevin Kelley, a Southern California Edison Co. spokesman. “Most of the outages were caused by tree branches falling on wires, or wires coming in contact with other wires.”

The powerful gusts, which whipped the Pacific Ocean into a calderon of white caps, began early Thursday morning as a low-pressure storm front moved through the Southland. Stephanie Hunter, a meteorologist with WeatherData Inc., a forecasting service for The Times, said the circulation around the storm, reinforced by air whirling around an adjacent high-pressure system, brought the unexpectedly strong winds.

Forecasters said the cold, blustery weather is expected to continue until Saturday--the official first day of winter--and more stormy weather could arrive on Sunday.

Hunter said skies should be clear today, but the winds will continue gusting up to 30 m.p.h. and overnight lows will be in the mid-40s, while the daytime highs could reach the low-70s. The winds are expected to decrease Saturday.

Highs in Orange County on Thursday ranged from 60 degrees in Newport Beach to 66 in Irvine and Laguna Beach. El Toro had a 65, while San Juan Capistrano reported a 64.

Hunter said that another “fairly strong” storm system might hit the area Sunday, bringing a chance of more rain in the Los Angeles Basin and more snow in the mountains.

The strongest winds were reported near Fillmore, in Ventura County, where gusts of up to 73 m.p.h. snapped a power line that sparked a brush fire beside California 126. Driven by the winds, the blaze spread rapidly, forcing the closure of the highway and briefly threatening a mobile home park largely inhabited by senior citizens.

The National Weather Service has posted snow and wind advisories for all mountainous areas in Southern California. Drivers through mountainous areas were asked to exercise extreme caution and to use tire chains where possible.

In Huntington Beach, the wind knocked out power to about 1,800 customers about 7:40 a.m. in the area of Garfield Avenue and Edwards Street. Power was knocked out to another 3,600 households at Beach Boulevard and Atlanta Avenue at 8:10 a.m.

Nearby in Costa Mesa, 2,200 homes around Santa Ana and Del Mar avenues went without electricity from 8:10 a.m. to 9:30 a.m. There were outages in other parts of the county but only a handful of households were affected, officials said.

“It’s fairly typical of what happens when we have high winds,” said Jerry Dominguez, a spokesman for Southern California Edison Co.

Mindy Berman, a spokeswoman for the Los Angeles Department of Water and Power, said the department estimated that about 20,000 customers lost power at one time or another during the morning. Kelley estimated that some 25,000 Edison customers were affected. The power outages were more widespread in San Diego County, where more than 83,000 customers were left in the dark for varying lengths of time.

Ironically, a blackout hit 14,000 homes and businesses in Fullerton Thursday night but the wind wasn’t to blame. A Southern California Edison spokesman said the blackout was caused by an underground cable failure.

At Irvine Avenue and 16th Street in Costa Mesa, Tom Garcia said police and firefighters cordoned off his block after the wind blew a wire off a utility pole near his yard and into the street.

“It was gusting out there,” said Garcia, who was surprised that some of the Christmas ornaments on a neighbor’s pine tree managed to stay in place. Garcia said he was without power until noon when power was restored.

Across the street at Newport Harbor High School, a branch from a eucalyptus tree almost hit a student, said Sandi Dekker, one of the school’s secretaries. “It could’ve killed somebody.”

Assistant Principal Steve Pavitch said it was fortunate that Newport-Mesa district maintenance crews were on campus doing yardwork. They were able to trim the damaged eucalyptus and save five young redwood trees, which were heeling over in the wind.

The 83rd annual Newport Harbor Christmas Boat Parade could be canceled if winds are greater than 30 m.p.h. this weekend. Every evening at 5 p.m. parade officials will survey the weather.

More than 200 decorated vessels and thousands of spectators turn out for the procession every year. In 1990, two nights of the weeklong event were canceled due to winds.

“As of right now, it’s a go. But wind is definitely a factor,” said Kristin Thom, a spokeswoman for parade. “If there’s going to be a steadily increasing wind, they’ll cancel the parade (for that night).”

Elsewhere, a snowstorm temporarily closed the main highway between Southern and Northern California. The Grapevine section of Interstate 5, the main artery linking Northern and Southern California, was closed in both directions at 4:35 a.m. Thursday.

Contributing to this story were staff writers Catherine Gewertz, Thuan Le, Jim Gomez, Ajowa N. Ifateyo, Rose Kim, Donnette Dunbar, and correspondent Lisa Mascaro.