Crews battling Southern California's enormous wildfire are struggling to widen and extend firebreaks before the return of winds that could once again drive the flames out of control.

The Thomas Fire is the second largest in 85 years of recorded California history. It's expected to become the largest as flames continue to eat into forest land.

Forecasts call for 20 to 30 mph winds with gusts to 60 mph by Wednesday evening in the coastal mountains northeast of Los Angeles.

That will end a three-day lull that allowed firefighters to contain about 60 percent of the fire, which is burning in Ventura and Santa Barbara counties.

Since it began on Dec. 4, the wind-whipped blaze has burned hundreds of homes and is blamed for the deaths of a firefighter and an evacuee.

It has burned 272,000 acres, destroying nearly 800 homes and damaging hundreds more.

The largest on record was the 2003 Cedar Fire, which burned a little more than 273,000 acres in San Diego County.

Cal Fire unit chief Scott Jalbert told KPCC the Thomas Fire is almost certain to surpass it.

"The increase of acreage is coming from the backside of the fire off Highway 33. That's the area where the fire's extremely remote into very rugged areas," Jalbert said.

Crews are working to tame the northern edge of the fire, where it meets the rough terrain of the Los Padres National Forest.

Firefighters have largely contained the fire's front end near Carpinteria, Santa Barbara and Montecito, but they're still mopping up hot spots in those areas.

More evacuations were lifted Tuesday, but communities remain threatened in Ventura and Santa Barbara counties.

Despite the return of high winds, Jalbert said they expect to extinguish the Thomas Fire by Sunday.

KPCC is updating a list of evacuations and road closures.

This post has been updated.