What’s the impact of Santa Ana winds on the LA fires?
California Power Shut-Offs Due to the Santa Anas Wildfires on Tuesday During the Second Ice Break in the First Two Months
The winds of Santa Anas are very violent in southern California, which is a part of life for many people.
The winds may come back next week. Mr. Thompson said that they weren’t catching a break. There is no rain in the forecast. This will be an ongoing issue for the next couple of weeks.
In anticipation, utility companies that serve the region warned they could begin shutting off power to some customers, though none had done so yet as of late Monday. San Diego Gas and Electric Company said it was considering power shut-offs for more than 64,000 customers as early as noon on Tuesday. It was considering cutting off nearly 400,000 customers, making it the largest pre-emptive outage in its history.
A red flag warning was issued for parts of Ventura, Los Angeles, and Orange counties on Tuesday and Wednesday. The previous two warnings came when the Mountain and Franklin wildfires began, and now it is the third time this season. Still, such warnings are rare: The National Weather Service had only given them twice before this year, both for warnings.
As of Tuesday afternoon, firefighters are working to contain a brush fire that is rapidly exploding in size, driven by 60 mph winds in residential areas of the Pacific Palisades in the Santa Monica Mountains. These gusty winds — which haven’t even reached the maximum predicted 80-100 mph yet — make firefighting difficult, picking up embers and dropping them up to 3/4 of a mile beyond the fire line.
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. Another 58,000 people have been warned to be prepared to leave at a moment’s notice.
Santa Ana winds and wildfires: How are they impacting the San Gabriel Mountains, the coastal mountain range and the Inland Empire area?
Santa Ana winds are more common during the cooler months in September through May, according to a lead forecaster at the National Weather Service. High pressure over the desert of the southwestern U.S. pushes through the mountain passages to an area of lower pressure off the Pacific coast.
The San Gabriel Mountains, coastal mountain range and Inland Empire area are all hit by strong air flow from Nevada, due to the high pressure that develops over that region.
The winds are known as katabatic and means they flow downhill, says a professor at Columbia University’s Climate School.
The air mass drops in altitude and it warms up quickly by 10 degrees Celsius per kilometer. She says it’s an effective way to warm up the air.
She says that as the air warms, it also decreases its humidity. 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.
“Obviously, we’ve got a zillion cars in the area. If one breaks down, overheats and someone pulls over next to an area where there’s some dry brush, that can kick it off,” he says.
The Los Angeles Area’s Dry Weather and Growing New Vegetation Over the Last Two Years: The HyFiVeS Scenario
Park Williams, a professor of geography who heads the HyFiVeS Research Group (Hydroclimate, Fire, Vegetation, and Society) at UCLA describes the current scenario as a “highly improbable sequence of extreme climate and weather events over the past two years.”
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.”
What are the consequences of climate change? As NPR has reported previously, a hotter atmosphere due to climate change can lead to the rapid spread of wildfires.
