The Hollywood Hills are in the sights of more fires

Katabatic Winds in the Southern Wildlands: Preparation for Wildfires and Implications for the Palisades and Eaton Fires

On Tuesday, Santa Ana winds swept through Southern California, scattering fire and setting it ablaze. By nighttime, residents received urgent text alerts warning of potential 100 mph gusts—a terrifying escalation that transformed a precarious situation into a full-blown crisis. As the winds howled, more embers took flight, sparking new fires in dry, brittle brushlands that hadn’t seen significant rain in over eight months.

The two largest blazes — the Palisades and Eaton Fires — have consumed more than 10,000 acres each and prompted mandatory evacuations for almost 70,000 people as of Wednesday. A lot of people have been warned to be prepared to leave.

Mike Wofford, a lead forecaster at the National Weather Service’s office in Oxnard, Calif., says the Santa Ana winds are most common during the cooler months from September through May. They are caused by high pressure over the desert of the southwestern U.S., that pushes through the mountain passages in Southern California toward an area of lower pressure off the Pacific coast.

“The high pressure that develops over that region, coupled with lower pressure down over southern California, creates this strong flow of air that comes out of Nevada and hits our coastal mountain range, the San Gabriel Mountains, and out to the Inland Empire area,” Wofford says.

The key characteristic is that the winds are what’s known as katabatic, meaning they flow downhill, says Mingfang Ting, a professor at Columbia University’s Climate School.

As the air mass drops in altitude, it compresses and heats up — by about 10 degrees Celsius per kilometer (18 degrees Fahrenheit per 0.6 of a mile). She says it’s an effective way to warm up the air.

“As the air warms up, it also decreases its humidity,” she says. Funneling through narrow mountain passes, it also speeds up in much the same way that air moving through a tunnel or the wind between buildings is stronger.

The result is wind gusts as high as 100 mph in some places, he says, adding that the current dry conditions mean, “everything is just primed and ready to go” for wildfires.

We have a lot of cars in the area. If one breaks down and someone pulls over next to a dry brush that can kick it off, that’s when the problem will start.

The Los Angeles fires and the climate: How quickly are the fires going to get bigger and bigger than usual, as they become more severe?

Park Williams is a professor of geography and the leader of the research group at UCLA that focuses on climate and weather.

It’s not just the dry weather this year, he says, but “from winter 2023 through spring 2024, the Los Angeles area experienced an exceptionally wet climate and this led to the growth of an extraordinary amount of new vegetation biomass in the hills and mountains surrounding the city.”

The fires turned catastrophic so quickly because of unusually dry and windy conditions: “Any little spark, whether from a lightning strike or a person or a campfire is going to quickly, quickly escalate,” says Jennifer Marlon, research scientist and lecturer at the Yale School of the Environment and the Yale Program on Climate Change Communication. “Once a fire starts in these conditions, it’s very, very hard to get under control,” adds Kaitlyn Trudeau, senior research associate of climate science at the nonprofit news organization Climate Central.

There is a dip in the jet stream near the Baja Peninsula that caused these winds to be stronger than usual. Winds that are usually relegated to higher elevations are reaching lower terrain areas. He says every so many decades we get wind events of this magnitude.

California Gov. Gavin Newsom said more than 7,500 personnel are responding to the fires across local, state and federal agencies. They are using helicopters, water tenders, air tankers and dozers to fight the fires.

A Santa Ana Wind Warning for Los Angeles County During the Sunset Fire and Its Implications for Existing Fires and Other Public Works Fires

“We just finished cleaning up from the Rose Parade of all things, and now this,” she said. “We had the big thing that showed off how wonderful life is here followed immediately by something showing off how awful life can be.”

When Cheryl Heuton moved with her husband to Pasadena, they were left with just toothbrushes, laptops and old stuffed animals that belonged to their children.

If a fire is deemed to be “immediate threat to life” and an order is issued for people to leave, then those who need more time to evacuate should do so.

The California Department of Fire Protection, called Cal Fire, says that only two fires have been somewhat contained: Lidia (40 percent) and Woodley (100 percent).

It was reported that the Sunset fire broke out, encroaching on the Hollywood Hills, and prompted mandatory evacuates in the area, such as Mulholland Drive, Hollywood Blvd and Runyon Canyon Park. The LA Fire Department said most of the evacuated areas had been cleared by Thursday morning.

“Gusty winds and very dry conditions will continue to fuel fire starts and existing fires,” it said, referring to the Palisades, Eaton and Hurst fires already burning in the area.

In Los Angeles County, nearly 30,000 acres were still burning early Thursday, as firefighters struggled to control a series of deadly blazes that have forced mass evacuated and leveled entire communities.

A wind advisory is in effect for at least 2 hours on Friday. To stay away from the downed power lines, the NWS recommends staying at least 100 feet away.

“Every once in a while we get a much stronger Santa Ana wind event like what we had over the past 24 to 36 hours, in which case we ended up with a widespread, life-threatening and destructive windstorm.”

The NWS chief meteorologist said that the winds are usually 30 to 60 mph and occur a couple times a year.

The NWS recorded speeds of 90 mph in Henninger Flats and 89 mph in Saddle Peak on Wednesday.

The Los Angeles School Fire Department Amenable for Families with Children 0 – 2 – 3 – 6 – 8 – 13 years after the Elementary Fires

“The confluence of factors — wind, fire and smoke — have created dangerous, complex situations that present unsafe conditions for our school communities,” the district said.

A major disaster declaration was made on Wednesday by the president, which provided federal funding to affected residents, with grants for temporary housing and home repairs and low-cost loans to cover uninsured property losses.

“Southern California, we are with you. The president scrapped a planned trip to Italy to focus on the fire response, and said that they were not letting up.

Red flag warnings have been extended through Friday for parts of Los Angeles and Ventura counties as gusty winds whip across the area and multiple fires burn out of control.