A new large wildfire broke out early Wednesday in Southern California, forcing mandatory evacuations at the Ronald Reagan Presidential Library and nearby neighborhoods.
Ventura County Fire Captain Brian McGrath said the Easy Fire erupted shortly after 6 a.m. local time and torched 165 hectares (400 acres) of dry brush within two hours.
The National Weather Service said the wildfire, which erupted in Simi Valley about 64 kilometers (40 miles) northwest of downtown Los Angeles, ranked among the most dangerous Santa Ana wind events "in recent memory."
Officials did not how many people had been ordered to leave.
Fire officials said aircraft dropped fire retardant and water on the blaze and that the strong Santa Ana winds pushed flames away from the library.
As firefighters in the southern part of the state prepared overnight for what forecasters expected to be one of the most significant wind events in years, a large wind-driven wildfire in Northern California eased.
Both regions are dealing with the hot, dry weather that is common at this time of year and raises the risk of big wildfires that spread when the winds blow.
Crews made progress Tuesday against both the Getty Fire in the south and the Kincade Fire in the north, with officials saying each was 15 percent contained.
The worry Wednesday and into Thursday was that the Getty Fire could swell from its current size of about 265 hectares (650 acres) as winds forecast to reach as much as 128 kilometers per hour (80 mph) lift embers and spread them into unburned vegetation or reignite areas that are merely smoldering.
Fire officials also warned that high winds could lead to the grounding of helicopters used to douse the flames from above.
Better outlook to the north
In Northern California's wine region, officials were expressing more optimism about the weather after days of near-record winds there pushed the Kincade Fire to more than 30,000 hectares (115 square miles) in size.
The National Weather Service said winds would be noticeably lighter Wednesday and that weather conditions looked favorable for the rest of the week, even though the region would remain dry with no rain in the forecast.
Along with the fires, people in California were also dealing with power outages as utility companies tried to prevent fires being sparked by equipment damaged by strong winds.
The Los Angeles Fire Department said Tuesday that the Getty Fire most likely had been caused by a tree branch that broke off in high wind and flew into nearby power lines, causing sparks that ignited brush.
About 1 million customers in Northern California were dealing with blackouts instituted by utility company Pacific Gas & Electric, which this month has been shutting off power in a series of blackouts that have caused widespread frustration among its customers.
California Governor Gavin Newsom has repeatedly criticized the company and its projections that it needs 10 years to institute reforms that would make the precautionary power shutoffs no longer necessary to mitigate fire risks.
In all, the National Weather Service has issued statewide warnings of dangerous fire conditions covering an 88,000-square-kilometer area (34,000 square miles) that is home to 21 million people.
Some scientists have said climate change is a contributing factor in the increasing frequency and intensity of wildfires.