Santa Ana Winds Ease, but Windstorm’s Return Could Accelerate Fires

The extreme Santa Ana windstorm that has spread wildfires through Los Angeles abated slightly on Thursday morning, but the calmer winds are likely to be only a brief respite.

Todd Hall, a meteorologist at the National Weather Service in Los Angeles, said that Southern California could face several more wind events — periods of sustained high winds — that could accelerate the fires spreading through the Los Angeles area. He said the wind was expected to pick up on Thursday night, then again over the weekend and possibly next week.

On Wednesday, the fire danger was extremely critical, with winds exceeding 60 miles per hour and sometimes reaching 100 m.p.h. The fire danger is not as high on Thursday, and the wind speeds won’t reach Wednesday’s levels. But with active fires still burning, the crisp, tinderbox-like environment in Southern California will still create critical fire weather conditions again on Thursday.

Winds are expected to strengthen through on Thursday evening, when another moderate to locally strong wind event is forecast, with wind speeds of 20 to 30 m.p.h. and gusts up to 60 m.p.h. Humidity levels are also expected to stay low, making an elevated fire risk still likely. A red flag warning for critical fire weather will remain until 6 p.m. local time on Friday.

Friday into Saturday, the wind speeds may relax, and fire weather conditions could improve, allowing firefighters to gain ground before another weaker wind event occurs Saturday night into Sunday morning. There is a chance that with Santa Ana winds returning, critical fire danger will return over the weekend.

While the conditions are not expected to reach the intensity or longevity of the current event, they could still prolong the fire threat, especially since Southern California’s vegetation remains critically dry. There has been little rain the region since last spring, with none forecast in the coming days.

Mr. Hall said that the wind event early next week “needs to be watched carefully,” as it could have gusts up to 80 m.p.h. And with yet another offshore wind event looming, forecasters are warning to stay vigilant.