Firefighters combating one of the biggest blazes in California history have been making headway, officials said Wednesday, but they warned that with gusty winds forecast, the region still faced the risk of “extreme fire behavior” through Friday.

The wildfires burning through the region in and around Los Angeles have consumed swaths of Southern California since last week, destroying more than 1,000 buildings — most of them single-family residences — and threatening thousands more. These fires, and the painful wildfire season that has ravaged the state this year, have been historic in scope and size: The largest active blaze — the Thomas Fire that erupted 10 days ago in Ventura County and spread into neighboring Santa Barbara — is already the fifth-largest California wildfire on record, according to Cal Fire.

Ventura County fire officials said Wednesday morning that firefighters responding to the Thomas Fire reported “good progress” overnight. But even as authorities said the blaze was 25 percent contained, it had still grown to expand across more than 370 square miles, and ferocious winds continued to pose a danger.

“Firefighters will remain engaged in structure defense operations and scout for opportunities to establish direct perimeter control,” officials said in an announcement Wednesday morning.

Evacuation orders for several areas have been lifted, including across the Ojai Valley area that saw extreme danger last week. The Thomas Fire has been blamed for the only death authorities have attributed so far to the recent spate of blazes. Last week, medical examiners in Ventura said that a 70-year-old woman had been killed by “blunt force injuries with terminal smoke inhalation and thermal injuries” during the fire evacuation.

What caused this blaze remains under investigation, officials said, which is also the case for many of the other recent fires that have forced evacuations, destroyed buildings and left people on edge.

Authorities have identified the cause of at least one recent blaze, saying Tuesday that the Skirball Fire — a much smaller blaze that destroyed six homes and damaged a dozen more in the affluent Bel-Air neighborhood of Los Angeles last week — was sparked by a cooking fire at a homeless encampment.

Firefighters keep watch on a wildfire burning the mountainside near the Cate School campus in Carpinteria, Calif. (Kenneth Song/Santa Barbara News-Press via AP)

That fire has been largely contained, as have some others throughout Southern California. The Lilac Fire, which had erupted in San Diego County and quickly burned across more than 4,000 acres and destroyed more than 150 structures, has been 95 percent contained, officials said. The Rye Fire in Los Angeles County, which grew to 6,000 acres, was 100 percent contained, officials said. In the same county, the Creek Fire that expanded across 15,000 acres was 98 percent contained by Wednesday morning.

California Gov. Jerry Brown (D) has called these blazes “the new normal.” Dry foliage, combined with powerful winds, provided wildfires with the fuel to expand and grow in an “extreme” way.

Forecasts suggested there would be still new dangers ahead. The National Weather Service said “red flag warnings” of heightened fire risk would remain through Friday morning over the Los Angeles and Ventura County mountains and the Ventura County and Santa Clarita valleys, with winds project to reach 50 mph in coming days.

Humidity will remain very low as winds will strengthen, which could lead to what the Weather Service called “extreme fire behavior,” which could include the rapid spread of any new blazes.

Further reading:

The Los Angeles fire that destroyed Bel-Air homes began at a homeless camp, officials say

Fire and fear stretch across Southern California as wildfires rage from Ventura to San Diego

California burned last year with fires fueled by historic drought