Orange flames explode through dry grasses along Lake Elizabeth Road on Thursday in Leona Valley, Calif. About 2,000 homes in the community of Leona Valley and parts of Palmdale were under evacuation Friday, according to Los Angeles County Fire officials.

Palmdale, Calif. ? A huge wildfire in the high desert wilderness north of Los Angeles jumped an aqueduct on Friday, rushing toward hundreds of houses as firefighters also tried to keep flames from damaging power lines that bring electricity to Southern California.

Some 2,000 structures were threatened and 300 homes were evacuated, Gov. Arnold Schwarzenegger said.

Destiny Brown, 19, stood beside her family’s tan Ford Taurus waiting for her mother and sisters to finish packing so they could leave their home in a smoke-clogged Delta Ridge subdivision on the outskirts of Palmdale.

“I never thought it would happen. I only thought it’s on TV. It’s really scary,” the 19-year-old said of the flames that burned just out of sight.

When their home filled with smoke, the family decided it was time to go. Brown said she was especially concerned about her 10-month-old brother who has asthma.

In the adjacent Amber Ridge subdivision, Barbara Murphy, 62, said she decided to stay put even though she and other residents in the development had lost power.

She said she felt secure in the center of the subdivision and had come through several fires unscathed during her decades living in the Antelope Valley.

“I’ve lived here for 43 years and I’ve never left the scene of a fire,” she said.

Winds apparently carried embers across the wide concrete channel, with flames rapidly spreading to backyard fences at the edge of Palmdale. Plumes of smoke streamed across the city of 139,000 as a predicted afternoon increase in winds finally arrived.

Helicopters dipped buckets into the aqueduct to make rapid water drops. No homes immediately appeared to have been damaged. Numerous fire engines were in the area. A giant Boeing 747 supertanker arrived over Palmdale to join the battle.

“As you see, we are deploying everything that we’ve got,” Schwarzenegger said at the fire command post.

Sustained winds of 10 mph to 20 mph were reported, said Los Angeles County fire Inspector Matt Levesque.

Temperatures neared 100 degrees with single-digit relative humidity and the National Weather Service predicted gusts in the area up to 50 mph Friday night. The fire has burned more than 20 square miles since erupting Thursday and was 20 percent contained, Schwarzenegger said.