Ahead of a weeklong heat wave that will bake Sacramento and most of Northern California in sweltering temperatures, Pacific Gas and Electric Co. is warning that critical fire danger may lead to the first public safety power shutoffs of the year in several areas to prevent the utility’s equipment from sparking wildfires.

On Sunday, officials of the Oakland-based company said its meteorologists were forecasting an “elevated” risk for shutoffs in parts of eight Northern California counties: Colusa, Glenn, Lake, Napa, Shasta, Solano, Tehama and Yolo. The power shutoffs are the first wildfire-safety blackouts undertaken this year by PG&E, which has come under consistent criticism for engineering power shutoffs in past years to ward off fires caused by its equipment.

The areas affected and timing of the shutoffs correspond with the National Weather Service’s red flag warning, which was issued for a wide swath of Northern California between 11 p.m. Monday and 8 p.m. Tuesday. Those dangerous conditions produce an increased risk for damage to the electric system that could ignite fires fueled by dry vegetation.

PG&E officials were not immediately available for comment Sunday.

Where will the power shutoffs happen?

The high fire risk conditions are expected to continue through the July 4 holiday as Sacramento and the surrounding region could reach 110 degrees on Wednesday. The weather service also issued an excessive heat warning for all of the Sacramento Valley between 11 a.m. Monday and 8 p.m. Saturday as temperatures are expected to exceed 105 degrees through the weekend.

While officials did not give a specific number of homes and businesses that would affected by the so-called PSPS, maps provided by the utility showed outages were planned the western reaches of Yolo County including Winters and homes south of Putah Creek, as well as in Rumsey, Guinda and around the Cache Creek area.

Other areas under a potential PSPS include homes on the western edge of the Valley west of Willows, Orland, Corning, Red Bluff and Anderson. A large area of potential shutoff ring the Redding area as well, along Highway 299 and in the Bella Vista and Palo Cedro areas.

Conditions ripe for fires, PG&E says

PG&E officials said in a weather update Sunday that in addition to the high temperatures, “there will also be a period of breezy northerly winds across primarily the northern and western Sacramento Valley and adjacent foothills” beginning Monday night.

Weather service forecasters and PG&E officials say breezes in some spots along the Valley’s western tier — from Solano County north to Red Bluff — could gust as high as 30 mph “although, localized gusts of 35-40 mph will be possible,” PG&E said.

PG&E forecasts are particularly concerned about conditions on the ground, noting that “the grass crop has cured across the lower elevations and dead fuel moisture values are at seasonal dryness levels.” That means that the combination of hot air, strong winds and tinder-dry grasses common in the Valley and foothills could lead to quick-moving fires.

The utility said in its weather update that it has already shifted 624 of 788 circuits in the affected areas to “enhanced powerline safety settings,” which adjust the sensitivity of the equipment to power off faster if a problem is detected. These buffers, according to PG&E, allow lines to be de-energized automatically “within one-tenth of a second” if vegetation or flames interfere with sagging lines or overheated transformers. Officials touted in a report to state regulators that such equipment settings reduced ignitions to its equipment by 68% in 2022.

PG&E blamed for past wildfires

PG&E in recent years has imposed planned power shutoffs in the face of dire wildfire weather. The utility company’s equipment has been blamed for sparking some of the worst fires in state history, including the 2018 Camp Fire that devastated Paradise, and PG&E Corp. has been found liable for billions of dollars worth of destruction.

The utility since 2017 has been blamed for starting more than 30 wildfires, blazes that destroyed more than 23,000 homes and businesses and has killed more than 100 people.

PG&E customers enrolled in its Medical Baseline program who have not verified that they received notification of the potential shutoffs will be visited at home by a PG&E employee when possible, the utility has said for previous outages. Officials said primary focus will be given to customers who rely on electricity for critical life-sustaining equipment.

The utility is also expected to open several “community resource centers” Tuesday in the blackout areas, enabling customers to cool off in the air conditioning, get free bottled water and snacks and charge their phones. PG&E mapping indicated those centers would be open beginning at 8 a.m. Tuesday in Redding, Anderson, Elk Creek and Stonyford, among other areas.

Restoring power to affected customers would likely take 12 daylight hours once the weather “all clear” has been given. PG&E crews need to inspect the de-energized lines to make sure they weren’t damaged during the wind event, according to the news release.

More information on the PSPS and how to get alerts are available on PG&E website.