SAN FRANCISCO − A weather phenomenon called the “Diablo wind” is approaching northern and coastal California, which may lead to preventive power outages for nearly 30,000 homes across 30 counties by Thursday, according to local utility officials.

In an effort to prevent wildfires, Pacific Gas & Electric has informed customers in extensive areas of northern and central coastal California about possible power shutdowns to reduce the chances of electrical sparks igniting fires.

The National Weather Service has issued a “red flag warning” for northern California from Thursday night until Saturday night, indicating that “critical fire weather conditions are likely or imminent.” Officials recommend that residents prepare an emergency plan in case of nearby fires.

The term “Diablo wind” refers to the hot, dry winds coming from the northeast that occasionally affect the San Francisco Bay area and central coastal regions of California, particularly during spring and fall. A similar weather event in Southern California is known as the Santa Ana winds.

Research indicates that climate change is increasing the frequency of extreme fire conditions driven by autumn winds.

“These winds are blowing from the north, rather than the usual cooler sea breeze,” explained Roger Gass, a meteorologist from the National Weather Service’s San Francisco Bay Area office.

This situation creates ideal conditions for fires to ignite and spread rapidly.

Past wildfires fueled by Diablo winds include the Oakland Hills Firestorm in 1991, which resulted in 25 deaths, starting from a small blaze on private land, and the Tubbs Fire in 2017, which claimed 22 lives and scorched 36,000 acres due to a private electrical system failure. Additionally, the Kincade Fire in 2019 in Sonoma County was sparked by a broken cable on a PG&E transmission line.

Cities at potential risk include Napa, Berkeley, San Jose, and Big Sur.

With warm temperatures, extremely dry vegetation, and high winds reaching speeds of 25 to 35 mph and gusts up to 65 mph, the situation is primed for a possible fire outbreak.

“This could be the highest risk for fires we’ve seen this year,” said Daniel Swain, a climate scientist at UCLA, on X.

Northern and central California have experienced a prolonged, hot, and dry summer, with some regions receiving little to no rainfall since July 1, as reported by Golden Gate Weather Services.

“The fuels are critically dry,” Gass stated. “If there had been rain, we wouldn’t be worried.”

This means activities like campfires, fire pits, or barbecues are discouraged. Off-road vehicle access is also prohibited to avoid igniting grass fires. Residents are advised against using lawn mowers or power tools outside and should check that trailer chains are not dragging on the ground, as the friction can create sparks.

As stated by the California Department of Forestry and Fire Protection, “One less spark, one less wildfire.”

“Most fires are human-caused,” Gass mentioned, noting that around 85% of wildfires start this way, according to the National Parks Service.