Residents piled into cars and fled on Saturday, turning downtown Santa Barbara into "a ghost town" as surging winds drove one of the biggest fires in California's history toward the city and the nearby wealthy enclave of Montecito.
The mandatory evacuations around Montecito and neighbouring Summerland came as winds that had eased a day earlier roared back at around 30mph, with gusts to about 60mph.
The 404-square-mile Thomas Fire was moving rapidly westward and crested Montecito Peak, just north of Montecito. Known for its star power, the enclave boasts the mansions of Oprah Winfrey, Ellen DeGeneres and many other celebrities.
"It is right above the homes," fire spokesman Jude Olivas said.
West Wing actor Rob Lowe shared shocking photos on Instagram of the fire raging just yards away from his home, as he urged his followers to "pray for Santa Barabara".
In another post, the star, who has also appeared in comedy series Parks And Recreation, revealed he had been helping the firefighters who have been battling to get the wildfire under control, but added: "when it's time... you GO."
Winfrey expressed her dismay on her Twitter account.
Still praying for our little town. Winds picked up this morning creating a perfect storm of bad for firefighters. #peacebestill ����— Oprah Winfrey (@Oprah) December 16, 2017
A follower asked her how her home was faring, to which she replied: "So far still standing. Praying for the Promised Land and everyone else's land. firefighters on the defence."
Chrissy Teigen and Paris Hilton were among the celebrities forced to flee their home.
Heiress Hilton wrote on Twitter: "This wildfire in LA is terrifying! My house is now being evacuated to get all of my pets out of there safely.
"Thank you to all the firefighters who are risking their lives to save ours. You are true heroes!"
Firefighters sprayed water on to hot spots sparked by wind-blown embers. Firefighters also drove to the historic San Ysidro Ranch in yellow fire trucks as heavy smoke rose from the coastal hills, blotting out the blue skies.
A portion of Santa Barbara was under mandatory evacuation. At the city's zoo, workers began putting some animals into crates and kennels, to ready them for possible evacuation.
In downtown Santa Barbara, Maya Schoop-Rutten, owner of Chocolate Maya, said she saw through the window of her chocolate shop smoke suddenly appear after strong winds blew through.
"It was absolutely incredible," she said. "There was a huge mushroom of smoke that happened in just a matter of a few minutes."
Restaurants and small stores on normally bustling State Street were shuttered.
"It's a ghost town. Everything is shut down," Ms Schoop-Rutten said. "It's very, very eerie."
Pierre Henry, owner of the Bree'osh Bakery in Montecito, said he got a text to evacuate on Saturday morning as the fire approached homes.
"The worst was the smoke," Mr Henry said. "You couldn't breathe at all and it became worse when the wind started. All the ashes and the dust on the street were in the air. It was very, very frightening."
The morning passed with no homes damaged or destroyed as firefighters dealt with "extreme and erratic" fire behavior, Mr Olivas said.
There was a spot of good news down the coast. Emergency officials announced that the same fire that was burning about 25 miles south-east of Montecito was 40% contained. Evacuation orders for the city of Ventura were lifted.
California wildfires cause thousands to flee, in pictures
As the northerly "sundowner" wind was driving the fire south and west, firefighters could only hope it would calm back down.
"When the sundowners surface in that area and the fire starts running down slopes, you are not going to stop it," Mark Brown, of the California Department of Forestry and Fire Protection, told a news conference. "And we are not going to stand in front of it and put firefighters in untenable situations."
Mr Olivas said 400 fire engines were sent to protect homes in the area. The fire is now the third-largest in California history. It has burned more than 700 homes and killed a state firefighter.
Cory Iverson, 32, died Thursday from burns and smoke inhalation, according to autopsy results announced on Saturday.
Since the fire began on December 4, about 95,000 people have been placed under mandatory evacuation. The evacuation zone near Santa Barbara on Saturday was 17 miles long and up to five miles wide and the new expansion encompassed about 3,300 people.