"As expected winds have increased dramatically", Cal Fire, the agency responsible for fire protection in the state, said on Twitter.
The fire had neared 13,000 acres and had destroyed 30 homes by late Wednesday, the Los Angeles Times reported.
More than 1,000 firefighters worked through the night protecting buildings, including City Hall, where the flames reached the parking lot, destroyed a couple of cars and left an adjacent hillside blackened and smoldering.
"If the winds pick up, we will face quite a challenge".
Chef and restaurateur José Andrés, whose World Central Kitchen organized chef volunteers and donations to serve more than 3 million meals to victims of Hurricane Maria in Puerto Rico, in a tweet indicated that his crew was on the way to Los Angeles to work with the Red Cross to feed those displaced by fire.
Erik Oberholtzer, co-founder of the Los Angeles-based chain Tender Greens, said no restaurants were impacted on Wednesday, but that he was concerned for the chain's partner farms in Ventura County, where the burn zone remained out of control Wednesday.
Elsewhere, use of firefighting aircraft has been constrained by the same winds that have spread the fires.
In issuing his emergency proclamation to secure state and federal disaster resources, Brown cited the destruction, the threats to critical infrastructure and the high winds.More news: Analysts See $3.92 EPS for Broadcom Limited (AVGO)
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The museum closed Wednesday while the fire was held back.
Below, a list of the freeway and road closures cause by the fires so far.
"Very strong winds" blowing from the northeast to the southwest were causing the fire to balloon, he said, warning Angelenos to be ready to flee at a moment's notice.
A major Santa Ana weather event with wind gusts between 70 and 80 miles per hour, and low relative humidity are to blame for the Skirball fire, which is threatening Los Angeles' affluent Bel Air neighborhood, officials said.
A Los Angeles County Fire helicopter flies over the Skirball Fire which began early morning in Bel-Air, Calif., Dec. 6, 2017.
The fires are the second outbreak to ravage parts of California this autumn. It is only 5 percent contained, The Times reported.
California utility companies can be held financially liable for wildfire damage linked to their equipment, even if they followed all applicable safety rules. Fire officials said the weather was making it hard for aircraft and helicopters to fight the blazes.
The Thomas Fire, which is raging through Avrea's hometown, is the largest of five active fires burning around the Los Angeles area.