Updated

The second-largest wildfire in state history burning in Southern California may grow further as strong wind gusts return to the region Thursday, after firefighters spent the past two days trying to contain the gigantic blaze.

The wildfire, which began on Dec. 4., has burned 272,000 acres and destroyed at least 750 homes, is now 60 percent contained but still threatens 18,000 structures.

Firefighters have spent the past two days taking advantage of calmer weather to build containment lines and douse hot spots, but wind gusts from the north nearly 60 mph are expected to create extreme fire danger conditions for Santa Barbara County on Thursday, the National Weather Service said.

Firefighters so far have been able to secure the Santa Barbara side of the fire, Battalion Chief Chris Childers of the Santa Barbara County Fire Department said during a community meeting on Wednesday.

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In this photo provided by the Santa Barbara County Fire Department, Santa Barbara County Firefighters haul dozens of pounds of hose and equipment down steep terrain below E. Camino Cielo to root out and extinguish smoldering hot spots in Santa Barbara, Calif., Tuesday, Dec. 19, 2017. (Mike Eliason/Santa Barbara County Fire Department via AP)

“The wind test is coming,” Childers said. “It will be the test to see if we have done everything correct.”

Ventura County, where the fire initially began, is forecast to experience 40 to 50 mph winds on Thursday and Friday. Officials have still not determined what sparked the blaze.

THOMAS FIRE IN SOUTHERN CALIFORNIA JOINS LIST OF DESTRUCTIVE BLAZES IN THE STATE

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In this photo provided by the Santa Barbara County Fire Department, firefighters follow a hose line while walking rugged and scorched terrain below E. Camino Cielo near Gibraltar Road in Santa Barbara, Calif., Tuesday, Dec. 19, 2017. (Mike Eliason/Santa Barbara County Fire Department via AP)

"If there's an ember that's been there for a day or two that's still glowing, that can be a real risk if the winds start blowing," fire information officer Brandon Vaccaro told the Associated Press.

Fire crews are stationed once again to provide structure protection above Montecito and other hillside communities in Santa Barbara County, where the last round of heavy gusts revived the flames and forced new evacuations last weekend

Some residents watched from afar at hotels and evacuation centers, while others are waiting in their homes and hoping for the best.

Tiffany Fariseo, who returned home Wednesday for the first time in a week, told the Los Angeles Times a power outage had spoiled her food, including two turkeys she had frozen for Christmas dinner.

“This really put us behind,” she told the newspaper. “When you live paycheck to paycheck, this impacts you a lot harder.”

SANTA ANA WINDS: WHAT ARE THEY?

Katy and Bob Zappala have stayed in their home in Santa Barbara, about 100 miles northwest of Los Angeles, despite an evacuation order that's been in place since Saturday.

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In this photo provided by the Santa Barbara County Fire Department, CAL FIRE Inmate Firefighting Hand Crew members hike through the charred landscape on their way to work east of Gibraltar Road above Montecito, Calif., Tuesday, Dec. 19, 2017. (Mike Eliason/Santa Barbara County Fire Department via AP)

"Our cars are packed, we have all our clothes and jewelry, so we're ready to leave at a moment's notice should we have to," Katy Zappala, 74, told the AP Wednesday.

The Zappalas and their cat, Madeline, haven't left home since the evacuation order was issued because authorities wouldn't allow them back in. They're starting to run out of food and are hoping that if they make it through the next wave of winds, the ordeal will be over.

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In this photo provided by the Santa Barbara County Fire Department, a pilot takes his firefighting helicopter back to fill its bucket with water while working near Gibraltar Road in Santa Barbara, Calif., Tuesday, Dec. 19, 2017. (Mike Eliason/Santa Barbara County Fire Department via AP)

"You're always nervous when the winds come up," Zappala said.

The Associated Press contributed to this report.