Prolonged heat wave in California increases risk of fires and power outages

Officials warn of extreme health and wildfire risks in California this week as the longest heat wave of the year begins Tuesday, bringing triple-digit high temperatures with little cooling, even at night, in the vast majority. of the state. .

“This is actually a long-duration heat event that will provide little to no impact overnight. [temperature] “It’s a relief,” said Antoinette Serrato, a meteorologist with the National Weather Service in Hanford. The prolonged heat wave is expected to bring dangerous temperatures over the July 4 holiday weekend in many areas, particularly in Northern California, the Central Valley and the deserts of the Southwest, extending into early next week, she said.

Much of the valleys and mountains of inland Los Angeles County, including the San Fernando Valley and San Gabriel Mountains, are included in an excessive heat advisory Wednesday through Sunday, when high temperatures of 95 to 110 are expected. degrees. However, most of the coast is expected to be largely spared the worst of the heat. The central counties of Los Angeles, Orange and San Deigo were not yet included in any heat advisory.

On Tuesday, a combination of excessive heat is expected to overlap with a red flag warning — an alert for extreme fire weather — in parts of the northern Bay Area and Sacramento Valley, raising concerns about potential fires. Low humidity, winds up to 30 mph and high temperatures could create the perfect storm for wildfires, officials warned.

Pacific Gas & Electric Co., the state’s largest utility, announced that power outages are likely Tuesday in some Northern California counties “due to high winds and dry conditions” as part of its safety power shutoff program that aims to reduce the chance of accidental fires. Counties that could be affected include Colusa, Glenn, Lake, Napa, Shasta, Solano, Tehama and Yolo, according to the utility’s website.

The California Governor's Office of Emergency Services also announced Monday that it had positioned fire trucks and personnel across the state, given the extended heat wave and threat of wildfires.

“A combination of strong wind, low relative humidity, and high temperatures may contribute to extreme fire behavior,” the National Weather Service wrote in its red flag warning for the inland mountains of the Sacramento Valley and North Bay, which lasted from Monday night through Wednesday.

But weather officials say the biggest concern this week comes from extreme and prolonged heat, which is expected to bring with it significant health risks.

“As we head into the weekend, there are many areas … that are going to experience extreme heat risk,” Serrato said, referring to the weather service's new heat risk tool. “Overnight minimum temperatures will be around 70 degrees in many areas, perhaps even higher.”

From northern Humboldt County to inland San Diego County, and virtually everything in between, the National Weather Service has issued an excessive heat warning this week, in most areas starting on Tuesday and will last at least until Friday, in some areas until Monday.

“This level of rare, long-lasting extreme heat, with little to no relief at night, affects everyone, especially those without effective cooling and/or adequate hydration,” the extreme heat warning for the Central Valley said. where high temperatures are forecast to remain at or above 107 degrees from Tuesday through July 8, the following Tuesday.

High temperatures will reach up to 121 degrees in the Coachella Valley and San Diego County deserts during the heat wave; High temperatures of up to 105 to 115 degrees are expected in the Antelope Valley.

In Death Valley, highs could reach 125 degrees later this week, where “low temperatures may not fall below 90 degrees for several days,” the weather service warned.

In the state's far northwest corner, weather officials are forecasting potentially record-breaking temperatures, and northern Humboldt County, including Hoopa, expects highs Wednesday through the weekend above 110 degrees. Trinity and Lake County could see areas as high as 115 degrees, the weather service warned. .

The National Weather Service's detailed forecast only extends for one week, but long-range predictions show a high probability that above-average temperatures will continue through at least July 10, according to the Climate Prediction Center.

This type of extreme and prolonged heat will affect everyone, including vulnerable populations such as infants, the elderly and pregnant people, Serrato said, urging residents to take precautions and seek out cooling centers set up across the state if necessary.

“Avoid going outside during the hottest parts of the day and make sure you stay hydrated,” Serrato said. “Try to stay cool and safe.”