Updated

Firefighters plan an aggressive air attack at first light Friday against a fast-moving wildfire that exploded in northern Los Angeles County, chewing through more than 7 square miles of dry brush, forcing hundreds of evacuations and burning at least three structures.

There is zero containment, authorities said.

Three water-dropping helicopters and hundreds of firefighters worked through the night to get ahead of the blaze which broke out around 3 p.m. Thursday on the northern side of State Route 14. By early evening the winds picked up and pushed the flames north and east toward Palmdale, in the suburbs of Los Angeles County's inland desert, authorities said.

Orange flames exploded through dry grasses, jumped roads and sped across the rural foothills that connect Los Angeles to the high desert.

"Man, it looks bad outside. If I step outside the restaurant, it's just insane looking — black and orange smoke and helicopters going through, dropping water," said Jamie Karschamroon, 29, the co-owner of Crazy Otto's diner in Leona Valley.

About 2,000 homes in the community of Leona Valley and parts of Palmdale areas were under evacuation Friday, according to Los Angeles County Fire.

Two outbuildings and a hay house were destroyed by the flames.

KCAL-TV showed at least two structures fully engulfed in flames near where the blaze jumped a road and sent firefighters and sheriff's deputies scattering.

"It's fuel and topography driven, but when fires have this much fuel and burn this hot they make their own wind," Levesque said.

State Route 14 snakes through the San Gabriel Mountains, connecting Los Angeles to the high desert. Angeles National Forest lands lie on either side. The area is west of the 250-square-mile zone scorched by last summer's Station Fire, the largest wildland blaze in county history.

About 200 firefighters contained another blaze at 350 acres, Levesque said. A third fire was stopped at 30 acres.

Further north in Kern County, good weather helped firefighters build containment lines around two wildfires that destroyed homes in remote mountain communities earlier in the week.

A 2½-square-mile blaze near Tehachapi on the western edge of the Mojave Desert was 44 percent contained after burning about 30 homes and other structures in a scattered community called Old West Ranch.

The community nonetheless remained evacuated, affecting about 150 people, said John Buchanan, spokesman for the California Department of Forestry and Fire Protection.

The blaze erupted Tuesday afternoon and rapidly swept through an area where Kern County fire authorities say there is no history of any fires on record, meaning vegetation hadn't burned there in more than a century.

To the north, a fire that destroyed eight residences and a few outbuildings as it spread across about 25 square miles of the Sequoia National Forest in the Sierra Nevada was 20 percent contained, authorities said.

The cause of the fires is under investigation.