Why the L.A. fires became so bad so quickly

Days after the National Weather Service in Los Angeles warned of extreme fire risk amid a “life-threatening and destructive” windstorm, a devastating and ongoing series of wildfires broke out in parts of the area - some in the mountainous zones where the strongest winds had been predicted.

The fiery outbreak was underway Wednesday amid a punishing windstorm in bone-dry January conditions. Several blazes exploded across the Los Angeles area beginning Tuesday, driven by hurricane-force winds that gusted to nearly 90 mph - winds that were only expected to intensify Wednesday morning.

As of early Wednesday, the Eaton Fire, which ignited in the hills northeast of Pasadena, had grown to more than 10,000 acres, causing two deaths and a number of injuries, destroying 100 structures and forcing evacuations in urban areas downslope of the fire. The 500-acre Hurst Fire in the Sylmar neighborhood in the San Fernando Valley ignited late Tuesday and spread at a dangerous rate, closing part of Interstate 5. And the destructive Palisades Fire on the L.A. area’s west side grew to more than 11,000 acres, burning 1,000 homes and threatening other stretches of the region as its tentacles reached toward heavily populated Santa Monica, Brentwood and Malibu.

The extreme behavior of the fires has so far made control nearly impossible. Videos shared online show a firestorm of embers carried by the powerful winds.

“A dangerous fire weather event is currently unfolding in portions of Southern California,” the Weather Service’s Storm Prediction Center wrote in an overnight update. " … Ongoing fires and any others that start will be capable of very rapid spread.”

The Weather Service had warned of a windstorm with sustained winds of up to 50 mph and widespread gusts of up to and exceeding 80 mph. It compared the event to a December 2011 windstorm that caused widespread damage in Pasadena - though fire danger was much lower that year. Ahead of this week’s winds, one fire meteorologist posting on X called the conditions “potentially a worst case scenario event.”

As these major fires erupted, numerous smaller blazes also sparked, though firefighters appear to have gained the upper hand on those.

In Southern California, the landscape is ultra-flammable because rains didn’t arrive after the long summer dry season, which was marked by extreme heat. Los Angeles and San Diego have seen less than a quarter-inch of rain this fall and winter.

“The fuels remain very available to burn as Southern California has yet to see the arrival of winter rains, leaving fuels parched after one of the warmest summers on record,” John Abatzoglou, a climatologist at the University of California at Merced, wrote in an email. “If the region would have had even close to normal rain this fall and winter, we would not be dealing with these fires.”

The unusually strong Santa Ana windstorm made the event a “recipe for disaster” he said, especially given the high population downslope of where the ignitions occurred.

“To have almost no precipitation at this point in the year is very unusual for us,” Alex Hall, a climate scientist at the University of California at Los Angeles, said in an interview. “Typically, we have our first rains in November … and it’s enough to quench the thirst of the plants that have been dormant for much of the summer.”

The rain would typically shut off the ability of Santa Ana winds - which ramp up in October and can blow through the winter - to create very large wildfires.

“What’s happened this year is we are getting our normal Santa Ana wind events, but we haven’t had any rainfall, so our fire season has been extended from October all the way into January,” Hall said.

In Southern California, more than 300,000 customers were had no power overnight. Southern California Edison cut power to about 75,000 customers to avoid sparking additional blazes.

Wednesday promised to be another high-risk day, as “extremely critical” fire weather continues for Los Angeles and Ventura counties.

But the risk will also begin to shift south, with fierce winds and critical fire weather stretching into San Diego County.

A “particularly dangerous situation” is expected for parts of Orange County and the Inland Empire between 7 a.m. and 1 p.m. Wednesday because of widespread strong winds, very dry air and critically dry fuels, the Weather Service said.

High fire danger will last through at least Thursday.

A recent report from Climate Central found that Southern California has had a marked increase in fire weather days since the early 1970s. Other recent research has found that wind-driven fires in the West are moving faster and burning more area annually in part because vegetation is becoming drier.