Extreme heat, elevated fire risk prompt power shutoffs in Northern California

LOS ANGELES — The start of an extended, potentially dangerous heat wave Tuesday has coincided with elevated fire conditions across Northern California, prompting Pacific Gas & Electric Co. to initiate the first planned power shutoffs of the year, expected to last at least through Wednesday.

PG&E, California’s larger power provider, implemented the public safety power shutoffs Tuesday morning across eight counties — Butte, Colusa, Lake, Napa, Solano, Sonoma, Tehama and Yolo — “due to high winds and dry conditions,” according to the utility’s website. The shutoffs are meant to prevent the utility’s equipment from sparking fires during dangerous conditions.

PG&E said the shutoffs early Tuesday morning affected approximately 2,000 customers. The utility said in a statement that it had “delayed the start of the planned [shutoffs] for approximately 10,000 additional customers — mostly in Glenn and Shasta counties ... due to favorable weather conditions.”

The power provider is still monitoring weather, and further shutoffs are still possible.

Much of the Sacramento Valley and Bay Area mountains are under a red flag warning — issued for elevated fire risk — as well as an excessive heat warning Tuesday. The red flag alert, issued through Wednesday evening, warns of a combination of winds up to 30 mph, low humidity and hot temperatures that “can contribute to extreme fire behavior,” according to the National Weather Service.

California firefighters are already battling several blazes across the state, most urgently the Basin fire, which is now burning more than 13,000 acres in the Sierra National Forest in Fresno County. It was 17% contained as of Tuesday morning, according to the California Department of Forestry and Fire Protection.

The fire is burning not far from the Balch Camp, an isolated community where more than 150 people were evacuated due to the flames. PG&E has power infrastructure there, but a spokesperson for the utility said none of its facilities had been affected as of Tuesday morning.

Firefighters also continue to battle the Fresno Lightning Complex blaze, which has remained at about 10,600 acres the last few days and was 86% contained, as of Tuesday morning.

“The extremely hot weather dries out plant material, increasing the risk of wildfire,” Cal Fire warned on social media. “Avoid activities that could spark a wildfire, such as parking on dry grass, dragging chains, or using equipment during the hottest parts of the day. Remember, one less spark means one less fire.”

The most dangerous fire weather should last only through midweek, but officials are warning that the extreme heat will be relentless, lasting in some areas of the state for a week or more.

“This is a prolonged heat event that will definitely bring serious concerns for heat-related illnesses if people don’t take proper precautions,” said Kate Forrest, a National Weather Service meteorologist in Sacramento. Forecasters are expecting this to be a potentially record-breaking heat event, with triple-digit temperatures lasting for several days and little overnight relief.

Redding could break or tie its record for the most consecutive days that hit over 110 degrees, currently set at six days in 1978. Wednesday through Monday are forecast to hit 110 or higher in Redding, with Saturday expected to be the hottest at 116 degrees, Forrest said, which would tie the current record. There’s a chance that the heat will last even longer.

“Its definitely going to be approaching that record,” she said.

The excessive heat warning across the state will be in effect from Tuesday through the weekend, in most areas. In addition, various regions will be under separate heat advisories tied to their specific forecasts.

Much of Los Angeles County’s inland valleys and mountains, including the San Fernando Valley and San Gabriel Mountains, are included in an excessive heat watch from Wednesday through Sunday, when high temperatures from 95 to 110 degrees are expected. Even Southern California’s coastal communities are included in a heat advisory from Thursday through Sunday, when temperatures could reach up to 95 degrees.

The Central Valley could see a week or more of excessive heat, with high temperatures forecast to reach or exceed 107 degrees from Tuesday through July 8.

Highs of up to 121 degrees are forecast for the Coachella Valley and San Diego County deserts. In the Antelope Valley, temperatures are forecast to reach up to 115 degrees.

In Death Valley, highs could peak at 127 later this week, while “low temperatures may not fall below 90 degrees for several days,” the weather service warned.

In the state’s farthest northwestern corner, officials are warning of some possible record-breaking temperatures, with highs above 110 expected in northern Humboldt County from Wednesday into the weekend. Parts of Trinity and Lake counties could see highs of up to 115 degrees, the weather service warned.

Much of the inland Bay Area could see highs of up to 110 degrees. San Francisco, which could see highs in the low 90s, has been placed under a heat advisory for Tuesday and Wednesday, according to the National Weather Service.

“This will be a statewide heat event and it may last quite a long time,” UCLA climate scientist Daniel Swain wrote in a blog post Sunday. “Across inland areas, as well as at higher elevations, it’s entirely possible that temperatures may be continuously above average for the next 2+ weeks straight, into mid-July.”

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(Times staff writer Rachel Uranga contributed to this report.)