Evacuations were again ordered Friday in the 2,500-acre brush fire burning in steep, rugged terrain of San Francisquito Canyon, north of Los Angeles.
Flare-ups, meanwhile, tested homeowners' nerves as they watched firefighters and water-dropping aircraft battle the blaze during a second day of hot and dry conditions.
The fire was 15 percent contained as of Friday night.
A probation camp called Camp Mendenhall was being evacuated at about 2:30 p.m., as were areas north of South Portal Road and West of San Francisquito Canyon. The fire was moving north toward Lake Hughes Road.
A Red Cross evacuation center is set up at the Marie Kerr Park, located at 39700 30th St. West Palmdale, the Los Angeles County Sheriff's Department said. Large animals can be taken to the Antelope Valley Fairgrounds' Gate 3 at 2551 West Ave. H in Lancaster.
Containment of the Powerhouse fire, reported Thursday afternoon, was estimated at 15 percent Friday as crews fought the fire during another warm day in the Santa Clarita Valley, about 50 miles north of LA.
Flare-ups and spot fires were reported early Friday -- prompting the morning evacuation order -- and temperatures in the 90s are likely during the afternoon and weekend.
Evacuations had been ordered Thursday and then lifted.
Resident Frank Disesso watched with relief as water-dropping aircraft attacked the fire Friday morning.
"The embers were coming down, and they were so big they were burning my arms," said Disesso. "You could hear them hit all the oak leaves in the yard."
Homeowner Arlene Summers said her family used a fire hose to spray water on their house, yard and trees Thursday evening.
"No garden hose is going to get this under control," said resident Arlene Summers. "It's nerve-racking."
About 600 personnel from the U.S. Forest Service and Los Angeles County Fire Department are battling the fire, which burned power transmission lines and forced road closures Thursday as it burned uphill in steep terrain and heavy brush north of Santa Clarita. The department of water and power shut down larger transmission lines in the area.
The fire is burning away from Green Valley, a community within Angeles National Forest.
"We want to hit this as hard as we can with air resources and boots on the ground," said Nathan Judy, spokesman for Angeles National Forest. "We just want to make sure this fire doesn't switch and start heading back toward this way."
The fire was first spotted Thursday by a power plant station operator burning north of Power Plant 1 near San Francisquito Canyon Road.
There were no problems reported with SoCal Edision power lines Friday, according to utility spokesman Paul Klein. The fire appeared to be moving away from the lines, but crews continued to monitor the fire's direction.
A firefighter injured when a rock fell on his leg was treated and released. No other injuries have been reported.
Evacuation orders for about 200 homes south of San Francisquito Canyon and Spunky Canyon were lifted at 10 p.m., according to a U.S. Forest Service official. Mandatory evacuations ordered Friday morning for the Green Valley area have been lifted.
The fire prompted a weekend air quality advisory for residents in the Santa Clarita Valley and San Gabriel Valley mountain areas.
"In all areas of visible smoke or where there is an odor of smoke, all individuals are urged to be cautious and to avoid unnecessary outdoor activities," said Dr. Jonathan Fielding, director of public health for Los Angeles County.
Firefighters have responded to several wildfires during a hot, dry and windy May in Southern California.
The nearly 2,000-acre White fire in Los Padres National Forest, which started Monday, was 100 percent contained Friday north of Santa Barbara.
On Tuesday, the Magic fire burned about 150 acres near Six Flags Magic Mountain theme park in Valencia.
The Grand fire started May 15 near Frazier Park. Crews continue to monitor the area after the fire burned more than 4,000 acres, but little to no fire activity has been observed, according to the U.S. Forest Service web site.
NBC4's Melissa Pamer contributed to this article.