By Laila Kearney
SAN FRANCISCO (Reuters) - Firefighters battling a blaze that has destroyed 22 homes along California's scenic Big Sur coastline were counting on lower temperatures and more favorable wind conditions to help them suppress the flames, officials said on Wednesday.
The Pfeifer Fire blackened some 769 acres and was 20 percent contained by Wednesday morning, U.S. Forest Service spokeswoman Lynn Olson said, adding that crews expect to contain it fully by late Friday.
The flames were burning mainly on Pfeiffer Ridge in Big Sur, a mountainous coastal region south of the Monterey Peninsula that reaches into the Los Padres National Forest.
So far, the fire has forced 100 people to flee their homes, Olson said. All of the homes destroyed were likely burned early Monday morning, shortly after the fire erupted, and were located on Pfeiffer Ridge.
More than 800 firefighters were working to suppress the flames on Wednesday, but the area's treacherous landscape -- with high cliffs and quick-burning brush -- has hindered their efforts to build containment lines, Olson said.
She said a drop in temperatures and a rise in humidity made firefighters "optimistic" about battling the blaze. "The big chat today is the weather," Olson said.
A shift in winds, expected by Wednesday afternoon, could push the fire back, aiding the firefight, she said.
The fire was burning mostly on the ocean side of Highway 1, which runs roughly parallel to the Pacific coast in central California, U.S. Forest Service spokesman Andrew Madsen said. The picturesque highway has remained open despite the fire.
The cause of the fire was under investigation, Olson said. It started at around midnight on Sunday near the Big Sur Lodge, about 25 miles south of Carmel.
Big Sur, famed for its beaches, coastal redwoods and panoramic views of the ocean, is home to a mix of multimillion-dollar houses and eclectic, fringe-living communities.
(Editing by Dan Whitcomb and Dan Grebler)