Santa on Tuesday Anna’s winds blew seaward across Southern California, scattering embers and fanning the flames of growing wildfires. By night, residents received emergency text alerts warning of possible wind gusts of up to 160 mph. This was a frightening escalation, turning a volatile situation into a full-blown crisis. As the wind howled, more embers took flight, sparking new fires in dry, fragile scrubland that hadn’t seen significant rain in more than eight months.
Los Angeles County, hit by drought-like conditions, was like a tinderbox waiting for a spark. Firefighters struggled with strong winds that caused planes to drip and fire retardants to be taken out of service. “All Los Angeles County residents are at risk,” authorities warned in a press release Wednesday morning. Tens of thousands of residents have since been evacuated under evacuation orders, and thousands more are awaiting updates. By Wednesday evening, three large fires had burned more than 13,000 acres, and containment efforts were slow. The Palisades Fire in Pacific Palisades and Malibu, the Hearst Fire in Sylmar, and the Eaton Fire near Pasadena show no signs of slowing down as of this writing. At 0 percent, it is already the most destructive in California history.
Unusually dry and windy conditions quickly turned the fire into a catastrophe. “A small spark, whether it’s a lightning strike, a person, or a campfire, will spread quickly and rapidly,” says Jennifer Marlon, a researcher and lecturer at Yale University. Program on Climate Change Communication in the School of Environmental Studies and Yale University. “When fires start in these conditions, they are very difficult to control,” added Caitlin Trudeau, senior climate science fellow at nonprofit news organization Climate Central.
Santa Ana wind events are not uncommon. “We see it every year around this time,” said Jason Moreland, senior meteorologist at emergency communications platform AlertMedia. These downwind winds originating from inland are caused by dry high pressure from the northwest and low humid pressure from the south. “It’s like if you have a hose and you break it in half to shut off the water. If you cut a hole in your side, there’s a lot of pressure to get out of there,” Trudeau explained. “That’s basically what’s happening in the air.”
But these winds are much stronger than normal because of a dip in the jet stream near the Baja Peninsula in northwestern Mexico, Moreland said. Winds that would normally be driven to higher elevations are now reaching areas with lower terrain. “Every few decades we have a wind event of this magnitude,” he says.
Although this wind phenomenon seems extreme, Noah Diffenbaugh, a professor and senior researcher at Stanford University’s Woods Institute for the Environment, explains that it may simply be due to natural weather fluctuations, and that climate He said further research is needed to find out whether it is caused by fluctuations.
But while the winds are not unseasonable, climate change has increased the risk of late-season or early-season wildfires in California. “Not only are we having particularly high winds this time of year, but we’ve also had a particularly dry season here in early January,” Diffenbaugh said. Southern California’s rainy season, which runs from October to April, has seen record-low precipitation, following one of the driest on record. As climate change increases the variability of precipitation, the number of days when windy seasons and dry seasons overlap is increasing. “We’re seeing a significant increase in hot, dry, windy days, especially in Southern California,” Trudeau said.
(Tag Translation) Science
