California Governor Gavin Newsom, who was in Southern California to attend the naming of a national monument by President Joe Biden, made a detour to the canyon to see “firsthand the impact of these swirling winds and the embers,” and he said he found “not a few — many structures already destroyed.”

Officials did not give an exact number of structures damaged or destroyed in the Pacific Palisades wildfire, but they said about 30,000 residents are under evacuation orders and more than 13,000 structures were under threat.

And the worst could be yet to come. The blaze began around 10.30 am, shortly after the start of a Santa Ana windstorm that the National Weather service warned could be “life threatening” and the strongest to hit Southern California in more than a decade. The exact cause of the fire was unknown and no injuries had been reported, officials said.

The winds were expected to increase overnight and continue for days, producing isolated gusts that could top 160 km/h in mountains and foothills — including in areas that haven’t seen substantial rain in months.

“By no stretch of the imagination are we out of the woods,” Newsom warned residents, saying the worst of the winds are expected between 10 pm Tuesday and 5 am Wednesday local time.

About 15,000 utility customers in Southern California had their power shut off to reduce the risk of equipment sparking blaze. A half a million customers total were at risk of losing power preemptively.

The fire swiftly consumed just over 5 square kilometres of land in the Pacific Palisades neighbourhood in western Los Angeles, sending up a dramatic plume of smoke visible across the city. Residents in Venice Beach, some 10 kilometres away, reported seeing the flames. It was one of several blazes across the area.

Sections of Interstate 10 and the scenic Pacific Coast Highway were closed to all non-essential traffic to aid in evacuation efforts. But other roads were blocked. Some residents jumped out of their vehicles to get out of danger and waited to be picked up.

Resident Kelsey Trainor said the only road in and out of her neighbourhood was completely blocked. Ash fell all around them while fires burned on both sides of the road.

“We looked across and the fire had jumped from one side of the road to the other side of the road,” Trainor said. “People were getting out of the cars with their dogs and babies and bags, they were crying and screaming. The road was just blocked, like full-on blocked for an hour.”

An Associated Press video journalist saw a roof and chimney of one home in flames and another residence where the walls were burning. The Pacific Palisades neighbourhood, which borders Malibu about 32 kilometres west of downtown LA, includes hillside streets of tightly packed homes along winding roads nestled against the Santa Monica Mountains and stretches down to beaches along the Pacific Ocean.

An AP photographer saw multi-million dollar mansions on fire as helicopters overhead dropped water loads. Roads were clogged in both directions as evacuees fled down toward the Pacific Coast Highway while others begged for rides back up to their homes to rescue pets. Two of the homes on fire were inside exclusive gated communities.

Long-time Palisades resident Will Adams said he immediately went to pick his two kids up from St. Matthews Parish’s school when he heard the fire was nearby. Meanwhile, he said embers flew into his wife’s car as she tried to evacuate.

“She vacated her car and left it running,” Adams said. She and many other residents walked down toward the ocean until it was safe.

Adams said he had never witnessed anything like this in the 56 years he’s lived there. He watched as the sky turned brown and then black as homes started burning. He could hear loud popping and bangs “like small explosions,” which he said he believes were the transformers exploding.

“It is crazy, it’s everywhere, in all the nooks and crannies of the Palisades. One home’s safe, the other one’s up in flames,” Adams said.

Actor James Woods posted footage of flames burning through bushes and past palm trees on a hill near his home. The towering orange flames billowed among the landscaped yards between the homes.

“Standing in my driveway, getting ready to evacuate,” Woods said in the short video on X.

Actor Steve Guttenberg, who lives in the Pacific Palisades, urged people who abandoned their cars to leave their keys behind so they could be moved to make way for fire trucks.

“This is not a parking lot,” Guttenberg told KTLA. “I have friends up there and they can’t evacuate. … I’m walking up there as far as I can moving cars.”

The erratic weather caused Biden to cancel plans to travel to inland Riverside County, where he was to announce the establishment of two new national monuments in the state. He remained in Los Angeles, where smoke was visible from his hotel, and was briefed on the wildfires. The Federal Emergency Management Agency approved a grant to help reimburse California for the firefighting cost.

Film studios cancelled two movie premieres due to the fire and windy weather, and the Los Angeles Unified School District said it temporarily relocated students from three campuses in the Pacific Palisades area.

Recent dry winds, including the notorious Santa Anas, have contributed to warmer-than-average temperatures in Southern California, where there’s been very little rain so far this season. Southern California hasn’t seen more than0.25 centimetres of rain since early May.