The fifth largest wildfire in California history expanded, ripping through dry brush atop a coastal ridge while crews struggled to keep flames from roaring down into neighbourhoods amid fears of renewed winds.
Firefighters protected foothill homes northwest of Los Angeles, making progress in residential areas while much of the fire's growth occurred to the north in unoccupied forest land, Santa Barbara County Fire Department spokesman Mike Eliason said Tuesday.
"There were a couple of flare-ups in the hills that put on a light show last night, but they were expected. For now the teams are fighting the fire on their own terms," he said, adding that shifting winds are always a danger.
Red flag warnings for fire danger due to Santa Ana winds and a critical lack of moisture were extended into the week.
Meanwhile, investigators determined that the Bel Air fire near the world-famous Getty Museum was started by an illegal fire at a camp near a freeway underpass, according to city fire Capt. Erik Scott.
The camp was empty when firefighters found it but people apparently had been sleeping and cooking there for at least several days, he said.
Tens of thousands of people left are being subject to an evacuation order, including many from the seaside enclaves of Montecito, Summerland and Carpinteria and the inland agricultural town of Fillmore.
Those communities are still under significant threat from the fire, Cal Fire said in a statement.
Residents near a Carpinteria avocado orchard said the trees could end up saving their homes.
"You have a thick layer of leaves underneath the bottom and they are watered regularly, so it's like a sponge," Jeff Dreyer, who lives nearby, told KEYT-TV. "So the fire gets to the sponge full of water and it slows it down. It takes a long time for it to burn."
Latest HHHR Smoke dispersion from #ThomasFire at 4 PM pst today. Smoke will affect much of Santa Barbara County from the mountains to the coast, as well as Ventura County Coastal areas and possibly West L.A. late today. #LAfire #cawx #SoCal pic.twitter.com/swAe1Ky3fc— @NWSLosAngeles
Poor air quality kept dozens of schools closed. As ash rained down and smoke blew through streets, regulators urged people to remain inside if possible and avoid strenuous activity.
Uncommon offshore dryness
Officials handed out masks to those who stayed behind in Montecito, an exclusive community about 120 kilometres from Los Angeles that's home to stars such as Oprah Winfrey, Jeff Bridges and Drew Barrymore. Actor Rob Lowe was among residents who evacuated over the weekend.
The blaze — known as the Thomas Fire — has destroyed more than 680 homes, officials said. It was just partially contained after burning more than 930 square kilometres of dry brush and timber. The fire has been burning for more than a week.
To the north, San Francisco Bay Area firefighters quickly contained blazes Tuesday that destroyed at least two homes in hills east of Oakland — the site of a 1991 firestorm that killed 25 people.
Santa Ana winds have long contributed to some of the region's most disastrous wildfires. They blow from the inland toward the Pacific Ocean, speeding up as they squeeze through mountain passes and canyons.
The weather service said that if the long-term forecast holds, there will have been 13 consecutive days of dry offshore flow before it ends Friday afternoon. There have only been 17 longer streaks since 1948, including the record of 24 days set between December 1953 and January 1954.
High fire risk is expected to last into January.