Understanding the Santa Ana Winds: The Story of a Growing Wildfire and the Impact on Public Health and Public Works in Southern California, Prompt and During the Wet Season

On Tuesday, the Santa Ana winds swept through Southern California, fanning flames of a growing wildfire. 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.

“There’s no number of helicopters or trucks that we can buy, no number of firefighters that we can have, no amount of brush that we can clear that will stop this,” Eric Garcetti, then the mayor of Los Angeles, told me in 2019. The only thing that will stop this is if the earth relaxes into a more predictable weather state after we are gone.

The recent years of fire have started a discussion about its reasons, including whether the disaster landscape is caused by climate conditions or fuel build up from decades of fire suppression, and the extent that people have been pushed into the path of fire. At times like this, the arguments and policy implications are not as urgent as they could be, even when they are related to the same principle as the lesson: We are not prepared.

Climate change is making it more likely that late or early season wildfires will break out in California. This is a strong wind event and a dry season in January, according to Diffenbaugh. Southern California’s wet season, which runs from October through April, has seen record low precipitation, following one of the driest falls on record. Climate change is causing the overlap between the dry season and the windy season to increase. “We’re seeing a significant amount of more, hot, dry, windy days, especially in Southern California,” says Trudeau.

The winds are stronger than usual, partly because of a dip in the jet stream near the Baja Peninsula. Lower terrain areas are seeing some winds that are usually sent to higher altitudes. “Every so many decades, we do get wind events of this magnitude,” he says.

There are usually Santa Ana winds events. At this time of year, the senior meteorologist at Alert Media says, we see it every single year. These downhill winds, which originate inland, are caused by a dry high-pressure system coming from the northwest, and a low, humid pressure system from the south. “It’s like if you have a hose and you fold it in half to cut off the water. If you prick a hole in the side, you have a lot of pressure to get out,” explains Trudeau. The air is kind of like that.