The Los Angeles Wildfires: Two More Fires, Two More Power Outages Due to a Extremely Destructive Wind Storm
In addition to the fire risk, widespread damaging wind gusts, reaching 50 to 80 miles per hour, and even above 100 m.p.h. in the mountains, may knock down trees and power lines. The forecasters warned that this was going to be the most destructive windstorm since the San Gabriel Valley experienced powerful winds that caused extensive damage and closed schools in 2011. There could be similar damage to the Highway 118 and 220 corridors this week due to the storm.
After a short-lived dip in speed on Tuesday afternoon, the winds are expected to accelerate to dangerous levels from Tuesday evening into Wednesday morning. Gusty winds and dangerous conditions could linger into Thursday or even Friday.
Utility companies that serve the region warned they could begin shutting off power to some customers in anticipation, but none had done so as of late Monday. San Diego Gas and Electric Company was considering shutting down power for more than 64,000 customers on Tuesday. Southern California Edison said it was considering cutting off nearly 400,000 customers, one of its largest pre-emptive outages ever.
A rare “particularly dangerous situation” red flag warning was issued for portions of Ventura, Los Angeles and Orange counties, including downtown Los Angeles, for Tuesday and Wednesday. This level of warning has been issued two times this season, the first being in relation to the Mountain and Franklin wildfires. It’s rare to see such warnings. Before this year, the National Weather Service’s Los Angeles office had issued them only twice, both for warnings in 2020.
Firefighters are trying to put out a fast growing brush fire that is creating a lot of smoke and is caused by gusts of 60 mph in the Santa Monica Mountains. Firefighters have a hard time picking up debris and dropping it over the fire line when the winds are not even close to the maximum of 80-100 mph.
The largest of the two blazes is now consuming over 10,000 acres and has led to the mandatory departure of over 68,000 people. Many people have been warned to leave at a moment’s notice.
What are the Santa Ana winds and how are they impacting the LA wildfires? A professor at Columbia University explains the “Katabatic” wind
During the cooler months in September and May, the Santa Ana winds are most common. They are caused by the high pressure over the desert of the southwestern U.S. pushing through the mountain passages of southern CA toward the Pacific coast.
The San Gabriel Mountains, as well as the coastal mountain range, are hit by strong flow of air that comes out of Nevada, due to the high pressure that develops over that region.
The winds are known as katabatic, meaning they flow downhill, according to a professor at the Columbia University 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 that it’s an effective way of warming the air.
She says that the air warms up and decreases it’s humidity. It is the same speed as air moving through a tunnel or the wind between buildings if you go through a narrow mountain pass.
He says that the current dry conditions mean that everything is “just primed and ready to go” for wildfires.
We have a lot of cars in the area. He says that if one breaks down, someone pulls over next to the dry brush that can kick it off.
Climate Change and the Los Angeles Area: What have we learned in the last two years? Commentary on Park Williams and the HyFiVeS Research Group
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.”
He says the Los Angeles area experienced an extremely wet climate and that it caused the growth of a lot of new vegetation around the city.
What role might climate change play? As NPR has reported previously, a hotter atmosphere due to climate change can lead to the rapid spread of wildfires.