LOS ANGELES _ Large swaths of California will once again be without power as the state's largest utility prepares to cut electrical service to 179,000 customers as early as Wednesday afternoon amid heightened concerns that hot weather and strong winds could lead to wildfires.
Pacific Gas & Electric Co. announced Wednesday that it will begin shutting off power to customers in the Sierra Foothills about 2 p.m. An hour later, counties in the North Bay will lose service. By 1 a.m. Thursday, portions of San Mateo and Kern counties will also be in the dark.
"This Public Safety Power Shutoff decision was based on forecasts of dry, hot and windy weather that poses a higher risk for damage and sparks on the electric system and rapid wildfire spread," the utility wrote in a statement.
The shutoff is expected to impact customers in 17 counties: Alpine, Amador, Butte, Calaveras, El Dorado, Kern, Lake, Mendocino, Napa, Nevada, Placer, Plumas, San Mateo, Sierra, Sonoma, Tehama and Yuba.
Forecasters say peak winds should subside by noon Thursday in the Sierra Foothills, North Bay and San Mateo County and around noon Friday in Kern County.
Once the winds calm, the utility said it will inspect the de-energized lines to ensure they weren't damaged before turning power back on. However, many customers could be without power for at least two days after the winds subside, according to the utility.
Southern California Edison said more than 162,000 customers in six counties _ Ventura, Los Angeles, San Bernardino, Riverside, Orange and Kern _ could also face blackouts. It is not clear when power to those areas might be shut off.
San Diego Gas & Electric has identified about 24,000 customers in several communities that may be subject to a public safety power shut-off because of weather including high winds.
Gov. Gavin Newsom stepped up his criticism of PG&E, which came under intense criticism earlier this month over chaotic power shutdowns that impacted millions across Northern California.
"I believe the unacceptable scope and duration of the previous outage ... was the direct result of decades of PG&E prioritizing profit over public safety," Newsom wrote in a letter to PG&E Tuesday.
Red flag warnings were in effect beginning Wednesday in a large swath of Northern California as well the Los Angeles area.
Southern California is in the midst of a fall heat wave brought by a mixture of high pressure and offshore winds, with temperatures at least 10 degrees warmer than usual, said Jimmy Taeger, a National Weather Service meteorologist in San Diego.
Temperatures ranging from 90 degrees to more than 100 degrees are expected across much of the Southland. The coolest beaches in the region are expected to see the mid- or upper 80s, forecasters say.
The warming trend prompted the weather service to issue a heat advisory from 10 a.m. until 5 p.m. Tuesday, suggesting that people "drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors."
The heat will get a boost when Santa Ana winds arrive Wednesday night, bringing prime conditions for wildfires across the region. Forecasters say that although there's still some uncertainty about the strength of the winds, they anticipate peak gusts of 20 to 60 mph.
"There's a fire weather watch in place on Thursday and Friday, but we still have elevated fire weather conditions today with it being hot, dry and a little bit windy," Taeger said.
Even in light winds Monday, firefighters rushed to stop a blaze that quickly consumed about 40 acres in Pacific Palisades, burning dangerously close to multimillion-dollar homes in a hillside neighborhood and sending up a plume of smoke visible throughout the Los Angeles Basin.
In San Bernardino, firefighters took on a blaze that broke out Monday afternoon near homes in the Little Mountain area. The fire started shortly after 5 p.m. in thick brush near West 39th Street and North Severance Avenue. Aided by wind gusts of up to 30 mph, the fire raced up hills, burning 17 acres, damaging six structures and leaving two structures uninhabitable. The causes of both fires are being investigated.
Small fires that started Tuesday in Whittier, Riverside and Brentwood were quickly controlled.
High temperatures, low humidity and gusty winds are also expected in portions of Northern California on Wednesday and Thursday.