Update 7:06 p.m.: The fire has burned 1,800 acres and is still at 15 percent containment.
More than 800 personnel are now deployed to help battle the fire, which is burning toward the northwest.
A mandatory evacuation is in place for Mendenhall probation camp.
Firefighters hope to get further containment if the humidity holds for the night, according to Ron Ashdale, spokesman for Angeles National Forest.
Update 2:30 p.m.: Evacuations are in order for Camp Mendenhall and areas north of South Portal Road and west of San Francisquito Canyon, according to the Los Angeles County Sheriff's Department.
The fire has burned approximately 1,500 acres and is now moving northbound toward Lake Hughes Road. About 600 Firefighters are on scene fighting the brush fire as it remains at 15 percent containment.
Evacuation centers include:
- A Red Cross evacuation center has been set up at the Marie Kerr Park, located at 39700 30th St. West, in the City of Palmdale.
- The Evacuation for large animals has been set up at Antelope Valley Fairgrounds (Gate 3), located at 2551 West Avenue H, in the City of Lancaster.
Update 1:01 p.m.: The South Coast Air Quality Management District on Friday issued a smoke advisory for the Santa Clarita and San Gabriel Valleys because of the Powerhouse Fire.
"If you are smelling smoke, if you're seeing smoke you would definitely should not be outside exercising vigorously," said AQMD spokesman Sam Atwood. "And people who have heart disease or lung disease, including asthma, should take extra precaution and should even consider staying inside."
Atwood said the smoke advisory will be in effect until further notice.
Update: 11:44 a.m.: The fire has scorched 1,500 acres and remains at 15 percent containment, according to an official from Angeles National Forest.
Authorities now estimate the fire will be 100 percent contained by Wednesday, June 5.
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Update 11:17 a.m.: Los Angeles County health officials are advising that air quality in the Santa Clarita Valley and San Gabriel Valley mountains will be unhealthy for sensitive individuals throughout the weekend due to the Powerhouse Fire burning in the Angeles National Forest. Residents are urged to take precautions and avoid unnecessary outdoor activities.
Official figures on the fire remain at 1,400 acres burned and 15 percent containment.
Update 9:02 a.m.: Crews battling a wildfire in the mountains north of Los Angeles are taking advantage of cool morning weather to make progress but scattered flames continue to climb hillsides.
A flareup prompted authorities to briefly evacuate about 25 homes along a canyon road in the Angeles National Forest Friday morning but residents were later allowed to return.
U.S. Forest Service spokesman Nathan Judy says the 1,400-acre blaze north of Castaic is 15 percent contained and about 600 personnel, aided by air tankers, want to make more progress before hot, dry weather sets in this afternoon.
He says the blaze is burning near power lines although utilities report no damage.
Update 7:45 a.m.: As of 7 a.m., the Powerhouse Fire in the Angeles National Forest has scorched about 1,400 acres and was about 15 percent contained, according to the U.S. Forest Service.
About 550-600 firefighting personnel have been deployed. Seven helicopters and seven fixed-wing air tankers are being sent to assist in the firefighting effort.
Overnight, one firefighter suffered a minor injury.
The evacuation orders affecting as many 300 homes in the community of Green Valley near Palmdale that were lifted late Thursday night have not been reinstated. Authorities are closely monitoring the situation.
View PowerHouse Fire evacuation centers & closures in a larger map
Check back for updates.
Overnight evacuations were ordered as a 1,000-acre brush fire continues to burn Friday in San Francisquito Canyon near Santa Clarita.
Los Angeles County Sheriff Department in Palmdale confirmed that a limited 5:30 a.m. evacuation was ordered for a number of homes on San Francisquito Canyon Road in Green Valley — on Thursday, evacuations were lifted at 10 p.m. for about 200 homes in the area.
NBC LA reports that LADWP has shut down larger transmission lines in the area and "an evacuation center was set up at Marie Kerr Park located at 39700 30th St. in Palmdale...large animals that need to be evacuated can be taken to the Antelope Valley Fairground."
The "Powerhouse fire" faces windy, hot and dry weather on Friday could that could bring gusts "anywhere from between 25 and 35 mph," according to NBC4 forecaster Elita Loresca. According to the National Weather Service, temperatures in the area could reach the high 90s on Friday and stay hot through the weekend.
The fire in the Angeles National Forest surged to 1,000 acres Thursday and sent out big clouds of black smoke amid afternoon temperatures in the high 80s and winds gusting at more than 20 mph.
"The growth potential of this fire is great," Forest Service spokeswoman Sherry Rollman told the Associated Press. "It's burning medium to thick brush on steep slopes."
About 500 firefighters struggled to get near the fire that was hard to reach in steep terrain. Water-dropping aircraft were grounded overnight but set to return after daylight.
Both Southern California Edison and the Los Angeles Department of Water and Power said the fire was threatening their facilities and they were monitoring the blaze for potential problems, though none had been reported.
The lines that were in danger were transmission lines not distribution lines, and major outages were unlikely, LADWP officials said.
The blaze broke out at about 3:30 p.m. Thursday just north ofPowerhouse No. 1, a hydroelectric plant near the LA aqueduct that has been operating for nearly a century.
Seven hikers had been reported missing near the fire, but search teams learned that all had left the area safely on their own, sheriff's Lt. Steve Sylvies told the Los Angeles Times.
One structure has burned but it was not immediately clear what it was.
Check back for updates.
Update 9:12 p.m.: Hikers walked out on their own
Hikers feared missing in the area of the Powerhouse Fire were spotted walking out on their own and apparently in good condition, according to the L.A. County Sheriff's Department.
"In about the last half hour several hikers have been spotted and they are clear of that evacuation area," said Sgt. Brian Dorsey of the Palmdale station. "As of right now we don't have any further information as to additional hikers that are outstanding. The last set of hikers that came through actually stated that they believed they were the last ones on the trail."
Update 8:28 p.m.: zero percent containment, reports of hikers missing
As the sun went down over the Angeles National Forest, the Powerhouse Fire was 0 percent contained and over 1,000 acres. There were unconfirmed reports of hikers missing in the area, according to L.A. County sheriffs deputies.
Some 300 firefighters from Los Angeles National Forest and L.A. County had been deployed to help combat the fire, which had consumed more than 1,000 acres since it was first observed at 3:28 p.m., Angeles National Forest spokesman John Wagner said.
"It's grown rapidly moving in a northwesterly direction," Wagner told KPCC. "It's now 1000-plus acres is the latest of what we've received as far as an estimate of the size, burning brush and grass."
One DWP structure had been burned. Mandatory evacuations were in place for the Green Valley area, Wagner said.
Update 7:10 p.m.: Evacuation centers and road closures
Evacuation Centers (pets only)
Pets Castaic shelter:
31044 N Charlie Canyon, Castaic
5210 W Ave, Lancaster, CA
Antelope Valley Fairgrounds (for large animals):
2551 W Avenue H Lancaster, CA 93536
San Francisquito Canyon Road from Elizabeth Lake Road to Copper Hill Drive
Update 6:56 p.m.: 1,000 acres burned
L.A. County fire officials upgraded the Powerhouse Fire to 1,000 acres and said via Twitter that strike teams were on their way.
Both Southern California Edison and the Los Angeles Department of Water and Power said the fire was threatening their facilities and they were monitoring the blaze for potential outages, though none had been reported. Power was being rerouted away from the threatened lines.
The blaze broke out at about 3:30 p.m. just north of Powerhouse No. 1, a hydroelectric plant near the L.A. aqueduct that was the first to bring municipal power to the city and has been operating for nearly a century.
Los Angeles Times reporter tweeted the following picture of smoke billowing over the freeway:
Update 6:00 p.m.: More than 600 acres now burned
L.A. County Fire officials are reporting via Twitter that the fire has burned more than 600 acres.
NBC LA is monitoring the situation from the air and notes that animals are being evacuated as well.
Update 5:50 p.m.: Fire threatens power plant; homes being evacuated (400 acres burned)
Officials say a fast-growing wildfire north of Los Angeles has consumed 400 acres and is burning near power station transmission lines and homes are being evacuated.
The U.S. Forest Service says the fire started Thursday afternoon in the Angeles National Forest and quickly surged to 400 acres, sending out big clouds of black smoke amid temperatures in the high 80s and winds gusting at more than 20 mph.
The Los Angeles County Sheriff's Department is helping residents evacuate in the community of Green Valley. It was not immediately clear how many homes are threatened, but about 1,000 people live in the area.
Southern California Edison and the Los Angeles Department of Water and Power say the fire is near their facilities and they are monitoring the blaze for potential outages.
Update 5:24 p.m.: "Powerhouse Fire" has burned about 150 acres
Firefighters in Santa Clarita are battling a fast moving fire in the Angeles National Forest. The so-called Powerhouse Fire has burned about 150 acres above San Francisquito Canyon and is threatening some structures.
"[The fire] is running northwest. And we currently have about 100 firefighters on scene. It's steep terrain. It's brush and chaparral and there are power lines in the vicinity," said Sherry Rollman, a spokeswoman for the Angeles National Forest.
The cause of the fire is still under investigation.
Update 5:14 p.m.: Fire has burned 20 acres, threatens structures
A brush fire in the Santa Clarita area has burned about 20 acres. An Angeles National Forest spokeswoman says some structures are threatened.
The fire was reported about 3:30 p.m. and is burning uphill in steep, mostly brush-covered terrain. At least 100 personnel from the U.S. Forest Service and Los Angeles County Fire Department are on scene, NBC LA reports.
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Update 4:52 p.m: U.S. Forest Service officials reported a fast-growing brush fire burning in Angeles National Forest Thursday afternoon, according to NBC LA.
The fire broke out near San Francisquito Canyon and Powerhouse roads. It was not immediately known when it started or how many acres it had consumed.
Check back for updates.