Silverado and Blue Ridge fires threaten communities in Orange County

Residents watch the Blue Ridge fire from Vellano Club Drive Tuesday in Chino Hills.  (Irfan Khan / Los Angeles Times)

The sun shines through smoke in the air Tuesday in Chino Hills.  (Irfan Khan / Los Angeles Times)

A firefighting helicopter makes a drop on the Silverado fire, which has been fanned by gusty Santa Ana winds for a second day in the Whiting Ranch Wilderness Park in Lake Forest.  (Allen J. Schaben / Los Angeles Times)

Orange County firefighters battle Blue Ridge fire along 3700 block of San Antonio in Yorba Linda.  (Irfan Khan/Los Angeles Times)

Blue Ridge fire burns close to oil derricks along Aspen Avenue in Yorba Linda.  (Irfan Khan / Los Angeles Times)

A flare-up fills the sky with smoke from the Silverado fire burning in Irvine on Tuesday.  (Allen J. Schaben / Los Angeles Times)

An air tanker drops fire retardant behind homes Tuesday in Chino Hills.  (Irfan Khan / Los Angeles Times)

Yorba Linda residents gather around an Orange County Fire Authority vehicle at the intersection of Fairmont Boulevard and San Antonio Road, inquiring about the Blue Ridge fire that was burning close to their homes.  (Irfan Khan / Los Angeles Times)

Firefighter Raymond Vasquez fights the Silverado fire, fueled by Santa Ana winds, at the 241 Freeway and Portola Parkway in Irvine.  (Allen J. Schaben / Los Angeles Times)

A crowd watches a hillside burn on Foxtail Drive and Lotus Avenue in Yorba Linda.  (Myung J. Chun / Los Angeles Times)

A homeowner watches flames burn a hillside near Foxtail Drive and Lotus Avenue in Yorba Linda.  (Myung J. Chun / Los Angeles Times)

People watch the Blue Ridge fire burn on Foxtail Drive in Yorba Linda.  (Myung J. Chun / Los Angeles Times)

A hillside burns near Foxtail Drive and Lotus Avenue in Yorba Linda.  (Myung J. Chun / Los Angeles Times)

A bicyclist takes a look at fire activity on Via Lomas de Yorba amid the Blue Ridge fire in Yorba Linda.  (Myung J. Chun / Los Angeles Times)

An air tanker drops fire retardant on a ridge near the Green River Golf Club in Corona.  (Myung J. Chun / Los Angeles Times)

A hot spot flares in the Silverado fire at the 241 Freeway and Portola Parkway in Irvine.  (Allen J. Schaben / Los Angeles Times)

A water truck operator runs through the thick smoke of the advancing Silverado fire at the 241 Freeway and Portola Parkway in Irvine.  (Allen J. Schaben / Los Angeles Times)

Firetrucks convoy through thick smoke on Portola Parkway to battle the advancing Silverado fire.  (Allen J. Schaben / Los Angeles Times)

Firefighter Raymond Vasquez braves tall flames as he fights the advancing Silverado fire.  (Allen J. Schaben / Los Angeles Times)

Firetrucks convoy through thick smoke on the 241 Freeway to battle the advancing Silverado fire.  (Allen J. Schaben / Los Angeles Times)

A water truck operator is overcome after running through thick smoke from the advancing Silverado fire in Irvine.  (Allen J. Schaben / Los Angeles Times)

An Orange County Fire Authority firefighter stands ready to defend a home as the Silverado fire approaches the Orchard Hills neighborhood of Irvine.  (Allen J. Schaben / Los Angeles Times)

Orange County Fire Authority firefighters defend homes as the Silverado fire approaches the Orchard Hills neighborhood of Irvine.  (Allen J. Schaben / Los Angeles Times)

Orange County Fire Authority firefighters have to look away because of the gusty, hot wind, debris and approaching flames while defending homes from the Silverado fire in the Orchard Hills neighborhood of Irvine.  (Allen J. Schaben / Los Angeles Times)

Orange County Fire Authority firefighters do structure protection for homes in the Orchard Hills neighborhood of Irvine as the Silverado fire continues to burn.  (Allen J. Schaben / Los Angeles Times)