Another Santa Ana event, possibly the strongest of the season thus far and comparable to that seen during the Thomas and Woolsey fires, is set to bring ferocious winds and the threat of critical fire weather to Southern California starting Tuesday night.
The combination of powerful offshore winds and dry air is expected to bring "very high fire danger" to the region through Thursday morning, according to the National Weather Service.
The winds prompted the service's Oxnard office to issue its first ever "extreme red flag warning," NWS meteorologist Joe Sirard said.
The use of "extreme" is relatively new for the National Weather Service but adds to the sense of urgency, he said.
"This is not a routine red flag warning event," Sirard said.
The winds may rival those experienced during the Thomas Fire that began in December 2017, the Woolsey Fire of November 2018, and possibly even the October 2007 "fire storm" that burned more than 900,000 acres in Southern California, Sirard said.
The latest round of Santa Anas has the potential bring peak wind gusts of 50 to 70 mph in Los Angeles and Ventura counties, with isolated gusts of up to 80 mph possible in the Santa Monica and L.A. County mountains.
The region has seen Santa Anas of this strength in past, but these are especially dangerous because of their long duration plus the combination of very dry vegetation and extremely low humidity that persists overnight, Sirard said.
The winds could be the strongest in over a decade, according to the Los Angeles Times.
“This is the worst since we had an event in October 2007,” weather service meteorologist Tom Fisher told the newspaper. “Don’t let your guard down.”
Most areas of the Santa Ana, San Bernardino and Inland Empire mountains will experience gusts of 35 to 50 mph; wind prone coastal areas, meanwhile, could be hit with gusts of 20 to 30 mph, according to forecasts.
In other parts, it's expected to be at least as windy as it was last Thursday, when punishing gusts fueled the rapid spread of the destructive Tick Fire in the Santa Clarita area.
Humidity will drop into the single digits throughout the region, in some places down to 1 to 2 percent.
The National Weather Service warned those conditions could create the potential for "very rapid fire spread," as well as "extreme fire behavior with any fire ignitions."
Warning goes into effect at 11 p.m. Tuesday and expires 6 p.m. Thursday.
But the warm, dry conditions are likely to continue into early November, and may even linger through the middle of the month, according to NWS meteorologist Alex Tardy. That could spell for trouble for a state that has already experienced a series of destructive wildfires in just the past few weeks.
As of Tuesday, California has 11 active wildfires that Cal Fire considers significant. Among them are the Tick, Getty and Saddleridge fires in L.A. County, and the Kincade Fire in Sonoma County.
The state has experienced an uptick in fire activity over the past week, driven primarily by high winds and low humidity that have helped blazes spread rapidly.
“This is, unfortunately, now California’s normal,” Cal Fire Capt. Scott McLean said at a Monday briefing. “And it’s absolutely vital that everybody in this state be prepared for these weather events.”
KTLA's Melissa Pamer contributed to this article.