The Devil Winds Are Back — And So Is The Fire Danger

A red flag warning has been issued for Los Angeles and Ventura counties as the threat of Santa Ana winds looms. (Stock photo by Garry Knight via Flickr Creative Commons)

While for the rest of the nation fall means changing leaves and crisp sweater weather, here in Southern California it means Santa Ana winds season.

Which, in turn, means more announcements like this: red flag warnings have been issued by the National Weather Service for parts of Los Angeles, Orange, San Bernardino and Riverside counties. The L.A. area should expect critical fire weather conditions from late Wednesday night through early Saturday morning, as 55-70 mph Santa Ana wind gusts, temperatures in the upper 80s and relative humidity levels of 3-10% create dangerous conditions.

"We're pretty much getting into the heart of our typical Santa Ana season in the fall and winter," said Stephanie Sullivan, meteorologist with the National Weather Service in San Diego. "So, it's right on time."

As usually happens, we can look to the middle of the country for an explanation. A strong high pressure system is moving in behind a cold front over the Northern Plains. Cool air will travel over the Great Basin towards a lower pressure system along our coast. As the cool winds stream over our mountains, they'll compress, warm up, dry out and slam right into us.

Plants had until recently stayed pretty moist thanks to our wet winter and spring, but they've finally dried to dangerously crisp levels.

"We advise people to be extra cautious doing yard work or towing trailers or boats or anything that requires a chain — really anything that could cause a spark — to try to avoid those things if you can," said Sullivan.

SoCal Edison is considering whether to shut off power to more than 173,000 customers. In Central and Northern California, Pacific Gas and Electric could shut off power to 800,000 for days.

The Santa Anas should be gone by Saturday. Sunday is when temperatures are expected to start cooling back down. And hopefully our rainy season will arrive in time to avoid a repeat of the conditions that led to the Thomas fire.