The fires raging across Southern California are being fueled by gale-force winds that meteorologists say will worsen in the next two days as temperatures rise and humidity levels continue to plummet.
Forecasters from the National Weather Service and other meteorological organizations said they couldn’t recall such intense winds in Southern California, even in the heart of the Santa Ana season.
The conditions have been exacerbated by a La Nina weather pattern that meteorologists have warned about for months, saying it will bring a drier-than-normal winter in a region already dealing with the driest year on record.
Winds are expected to pick up at least until Tuesday, when forecasters say it’s possible that Los Angeles will match the all-time high of 95 degrees for that day.
“Not only is it a strong event, it’s one of the strongest events you’ll get in any Santa Ana season,” said Ken Clark, a Rancho Cucamonga-based senior meteorologist for Accuweather.com. “And the strongest winds have not occurred yet.”
Firefighters in Malibu were beating back flames amid gusts that neared 50 mph. In the Newhall Pass and Port Hueneme, gusts blew up to 78 mph Sunday, qualifying as hurricane-force.
In Fremont Canyon in the Santa Ana mountains, southeast of Yorba Linda, gusts reached 86 mph.
Gusts hit 108 mph at Whitaker Peak near Castaic Lake and 111 mph at Laguna Peak, near Point Mugu.
The powerful Santa Anas are the result of a cool high-pressure system in the Great Basin above Utah and a warmer low-pressure system along coastal Southern California.
The differential between the two systems is strong, causing winds to barrel over the desert and mountains, then through canyons to the ocean.
At the same time, other areas such as downtown L.A. and Pasadena experienced little, if any, wind Sunday.
“It’s a fickle combination of a lot of things, including the topography,” said Kelly Redmond, interim director of the Western Regional Climate Center at the Desert Research Institute in Reno.
“As the moving air makes its way to the coast, it doesn’t move as a uniform sheet of air. In some parts it stagnates, in other parts it speeds up.”
The erratic nature of the winds made it difficult for firefighters to battle the flames. In Malibu, the wind raged in the morning, ebbed around noon, then raged again in the late afternoon and evening.
“These add to the dilemma of people fighting fires or evacuating homes,” Redmond said.
“The winds are one way one minute, and it seems OK. Then they come right back again, and you think the world is ending.”
As Santa Ana winds move from high to low elevations, crossing deserts and mountains, they heat up.
That is bad news for firefighters, because the winds heat and dry already-parched vegetation.
“The relative humidity went from 60% to 70% around dawn to single digits: 5, 7, 8%,” Kenneth Reeves, director of forecasting for Accuweather.com said.
“It’s a classic example of drier air combined with wind to really cause some problems.”
The Santa Ana season peaks in December and can stretch into the spring.
So there was no reason to believe that the outlook would get better soon.
It could become markedly worse as winter approaches, they added, because of La Nina.
“We’re in La Nina. And it’s an increasing La Nina,” Clark said. “It’s intensifying. And that doesn’t bode well. In terms of the wildfire situation, it obviously doesn’t bode well.”
Last year, federal meteorologists forecast an El Nino condition that would bring above-normal rain to Southern California. That proved to be a dud, and Los Angeles was drier than ever in its recorded history.
But experts say this La Nina could turn into one of the strongest the region has had in years.
La Ninas do not cause Santa Ana events, but the dry conditions worsen their effects.
And unlike El Ninos, which can easily defy accurate prediction, forecasters have a much better record with La Ninas.
Eight of the last 10 forecast La Ninas resulted in drier-than-normal conditions in the Southland.
“In the long-range forecasting business, there’s always the contrarian,” said Bill Patzert, a climatologist for the Jet Propulsion Laboratory in La Canada-Flintridge. “But the contrarian seems to be pretty absent at this point. I’ve got a lot of compassion for the firefighters. The consensus is it’s going to be another dry year in the Southland.”
Patzert said these winds were notable not just for their power but their longevity.
“This Santa Ana has got legs,” he added. “This could be a 72-hour event. And when the winds get this strong, it’s really dangerous.”