By Christina Hoag
The Associated Press

AP Photo/Marcio Jose Sanchez Members of the Platte Canyon fire crew, out of Bailey, Colo., take down hot spots in Big Sur, Calif., Monday. Firefighters continue to fight the Basin Complex Fire in the Los Padres National Forest.

LOS ANGELES — A day of gains on the California firelines could be giving way to days of trouble.

The return of some residents to their homes Monday marked progress against the siege of wildfires, but forecasters warned that weather is turning the advantage back in favor of the flames.

"A high pressure system is setting up over the entire West," said Mike Smith, a meteorologist with the National Weather Service in Sacramento. "So in addition to the very warm temperatures we're getting, we'll also be getting a little bit of offshore wind over the next couple of days, which keeps the moist marine air from coming inland."

The turn toward hot and drier weather comes as three major forest blazes — a blaze above the city of Goleta west of Santa Barbara, another 150 miles to the northwest at Big Sur and a third fire in the southern Sierra Nevada — are all less than half contained.

Those fires, considered the most dangerous, were among more than 300 still uncontained from some 1,780 that have scorched more than 960 square miles of California in two weeks. Most were started by lightning strikes, but several are believed to have been human-caused.

Some 100 structures statewide have been destroyed. One firefighter died of a heart attack.

The 15-square-mile fire near Goleta was 35 percent contained late Monday, mostly on its southern side near neighborhoods. More than 2,000 residents were able to return home.

"We recognize that the west end is problematic," Goleta Mayor Michael Bennett said. "But the north and the northeast corner will be contained soon and then we can maybe take a deep breath and relax."

Some mandatory evacuation orders and warnings to be ready to leave remained in effect for scattered homes on the fire's growing western flank on the Santa Ynez Mountains.

Roger Aceves, Goleta's mayor pro tem, said residents were immensely grateful to firefighters, who in some instances beat back flames from front doors. But they were still concerned that the fire could whip up again.

"We know what can happen," Aceves said. "This is brush that hasn't burned since 1955."

Five fresh "hot shot" crews from Arizona and New Mexico, totaling 100 firefighters, were brought in Monday to the region about 100 miles northwest of Los Angeles.

About 36,000 customers in Santa Barbara County lost power around 8 p.m., said Southern California Edison spokeswoman Nancy Williams. Nearly all had their power restored within an hour, she said. It was at least the sixth straight day that transmission lines have been affected by flames and smoke.

Officials for the 125-square-mile blaze near Big Sur and the 41-square-mile fire in the Sequoia National Forest east of Bakersfield said those blazes won't be controlled for at least another two weeks.

The fire near Big Sur, was 18 percent contained and raging through the remote Ventana Wilderness where difficult access made it hard to build containment lines, said Jim Turner, spokesman for the U.S. Forest Service.

A mandatory evacuation remained in effect Monday for all residents of Big Sur. Firefighters were struggling to widen fire lines near Highway 1 and residential areas to between 300 feet and a quarter mile, Turner said.

Crews secured a Boy Scout camp Monday by burning out brush between the buildings and the wildfire's edge and were setting controlled fires elsewhere to halt the blaze's march, the Forest Service said.

The fire in the southern Sierra Nevada was 26 percent encircled. Unexpected winds pushed it on several flanks Monday, causing flames to jump western containment lines and run up Brown Peak. Air tankers and helicopters dumped flame retardant.

"The steep, challenging terrain makes it tough to work directly," said Bob Kurilla, fire spokesman. "It will take a little while, but we're making progress."