It's Lights Out in a Dozen Counties in California

UPDATE Oct 18, 2024 12:36 PM CDT

Pacific Gas & Electric had warned earlier this week that targeted power shut-offs may be necessary as a preventive measure before powerful "diablo winds" slammed into parts of California, to prevent electrical sparks from starting wildfires due to the hot, dry wind gusts. On Friday morning, 13,000 PG&E customers woke up to find the utility made good on its promise, turning off electricity starting Thursday evening in 12 counties, reports the AP. The affected counties include those near San Francisco, such as Alameda, Contra Costa, Napa, Solano, and Sonoma counties, as well as some further north like Colusa, Glenn, Tehama, and Shasta counties. The utility warns that 20,000 customers in total could see their power temporarily nixed over the next couple of days.

Oct 18, 2024 1:30 AM CDT

A major "diablo wind"—notorious in autumn for its hot, dry gusts—is expected to whip up across Northern California on Thursday evening, causing humidity levels to drop and raising the risk of wildfires, the AP reports. Forecasters have issued red flag warnings for fire danger until Saturday from the central coast through the San Francisco Bay Area and into northern Shasta County, not far from the Oregon border. Sustained winds reaching 35mph are expected in many areas, with possible gusts topping 65mph along mountaintops, according to the National Weather Service.

"This could end up being the most significant wind event for this year so far," said meteorologist Brayden Murdock with the service's Bay Area office. "We want to tell people to be cautious." During a diablo wind, common in the fall, the air is so dry that relative humidity levels plunge, drying out vegetation and making it ready to burn. The name—"diablo" is Spanish for "devil"—is informally applied to a hot wind that blows near the San Francisco region from the interior toward the coast as high pressure builds over the West. Pacific Gas and Electric Co. said it was prepared to turn off power to a small number of customers in areas where strong gusts could damage electrical equipment and spark blazes.

story continues below

Targeted power shut-offs were also possible in Southern California, where another notorious weather phenomenon, the Santa Ana winds, are expected Friday and Saturday. Winds around greater Los Angeles won't be as powerful as up north, with gusts between 25mph and 40mph possible in mountains and foothills, said Mike Wofford, a meteorologist with the weather service's Los Angeles-area office.

(More high winds stories.)