Updated Thursday, 10:45 a.m.

Fire crews continue to battle a series of rapidly moving conflagrations in the Los Angeles area -- highlighted by a blaze that erupted Wednesday before dawn near the exclusive Bel Air community and forced the closure of Interstate 405.

That fire, burning in Sepulveda Pass between the San Fernando Valley and L.A. basin, destroyed several homes in one of L.A.'s most exclusive neighborhoods.

Fierce Santa Ana winds whipped up the most destructive of the wildfires on Monday evening. By Thursday morning, the blaze dubbed the Thomas Fire had burned 96,000 acres in Ventura County, northwest of Los Angeles, and was 5 percent contained. The Thomas Fire threatens 15,000 structures, according to Cal Fire.

The fire prompted evacuation orders for about 27,000 people. Cal Fire has said at least 150 structures have burned but added that it expects that number to grow as damage is assessed.

The second-largest blaze -- the Creek Fire, burning in Los Angeles County at the northern edge of the San Fernando Valley -- had burned more than 12,000 acres, is 10 percent contained and triggered mass evacuations as well as the closure of part of Interstate 210.

At a news conference Tuesday afternoon, officials reported that 30 structures had been lost in the Creek blaze. Approximately 2,500 homes had been evacuated in that blaze and an estimated 150,000 residents had been affected.

Two firefighters were injured, officials said. No civilian injuries or deaths were reported.

Authorities reported zero containment on both the Thomas and Creek blazes.

L.A. Mayor Eric Garcetti declared a local emergency in response to the Creek Fire.

The 7,000-acre Rye Fire in Santa Clarita -- now 15 percent contained -- shut down a section of Interstate 5 on Tuesday.

Dry, gusty winds drove the Thomas Fire after it ignited Monday evening and spread from Santa Paula into the city of Ventura. Most of the evacuated homes were in that 15-mile corridor.

Gov. Jerry Brown declared a state of emergency Tuesday in response to the Thomas Fire.

"This fire is very dangerous and spreading rapidly, but we'll continue to attack it with all we've got. It's critical residents stay ready and evacuate immediately if told to do so," Brown said.

Santa Paula and both the county and city of Ventura have also declared local emergencies, according to officials.

The National Weather Service says that winds are likely to pick up throughout Southern California's coastal and mountain areas and remain dangerous through at least Friday.

"The winds are expected to strengthen again tonight through Thursday with 18 to 24 hours of strong winds gusting to 50 to 75 mph," the National Weather Service in Los Angeles said in a red-flag warning updated Wednesday. "This is a significant period."

The high winds are accompanied by extremely dry conditions -- 6 to 12 percent humidity -- that can aid explosive fire growth.

Jayme Laber, an Oxnard-based hydrologist with the weather service, said these are the strongest Santa Ana winds L.A. and Ventura have experienced since 2012.

In a scene reminiscent of the October fires in the North Bay, video posted by the Los Angeles Times showed dozens of homes burning in one neighborhood as the fire raced through terrain that reportedly had not burned for decades.

Among the structures reported burned in the 80-plus square miles charred by the blaze were the Vista del Mar psychiatric hospital and the Hawaiian Village Apartment complex, both on the northern outskirts of Ventura.

"The fire growth is just absolutely exponential," Ventura County Fire Chief Mark Lorenzen said. "All that firefighters can do when we have winds like this is get out ahead, evacuate people and protect structures."

Power was reported out at one point to more than 250,000 customers in Ventura and Santa Barbara counties. Southern California Edison, the area's utility, said 20,000 people still had no electricity as of 8 a.m. and that some residents should be prepared to go days without power because of ongoing fire danger and the anticipated difficulty of repairs.

All public schools in Ventura and several neighboring districts were closed on Tuesday.

Weather also posed a challenge for crews facing the Creek Fire in Los Angeles County.

"We're in an extreme firefight," county Fire Chief Daryl Osby said in a morning briefing. "We had a very warm, dry summer, our fuels are at critical levels and they're very explosive, as you can see right now."

The newest fires come at the end of what has already been the most destructive fire season in California history in terms of property loss. Cal Fire says the series of October blazes that broke out Oct. 8 and 9 during a prolonged period of hot, dry, windy weather burned 8,900 structures in Sonoma, Napa, Mendocino, Lake and Yuba counties. More than half of the homes lost in the fire were in or near Santa Rosa.

Forty-four people are reported to have died in the October blazes, 24 of them in Sonoma County.

This post includes reporting from The Associated Press and KPCC.

This post has been updated.