As Southern California braces for the most significant heat wave yet this year, officials warn that the dangerously hot temperatures expected at the end of the week are only one of three major concerns.
“It’s a trio of impactful hazards affecting Southern California as we head into the next several days: heat, fire and storms,” said Ariel Cohen, the meteorologist in charge at the National Weather Service’s Oxnard office. “Everyone needs to be getting prepared now.”
Extreme heat will build across the Southwest on Wednesday and is expected to bring near-record temperatures to Southern California through the weekend, creating major fire and health concerns. Those threats will be compounded by the possibility of monsoonal thunderstorms that could bring localized flooding, debris flows, destructive winds and lightning beginning Friday.
“The dangerous conditions are going to be coming Thursday and sticking around through the first part of the weekend,” Cohen said.
The weather service has issued widespread extreme heat warnings, and for the mountains and foothills, red flag warnings went into effect Wednesday morning. Temperatures across the Southland are forecast to peak Thursday and Friday, with highs reaching from 95 to 105 degrees everywhere beyond the beaches, and up to 110 degrees in Los Angeles County’s interior valleys and deserts. There will be little relief from the heat overnight.
“Overnight lows will be above 70 in many areas, including downtown L.A.,” Cohen said. “We’re talking about significant impacts for anyone susceptible to the heat. Heat-related illnesses are expected to be a major issue, with the potential for fatalities.”
Los Angeles officials have joined in calls urging people to make plans to stay safe, including having access to air conditioning, rescheduling outdoor activities and having several methods to receive emergency alerts. The city announced it had added four cooling centers to its network of libraries and parks that will be open to the public. L.A. County residents can find a list of available cooling centers here.
“Heat causes more deaths in the U.S. annually than floods, storms, and lightning combined. Those most likely to get ill during the heat include older adults, young children, outdoor workers, athletes, and individuals with chronic medical conditions,” said Muntu Davis, Los Angeles County health officer. “If you or someone around you experiences symptoms of heat stroke or heat exhaustion, such as dizziness, nausea, rapid heartbeat, confusion, or passing out, seek medical help immediately.”
But down by the Santa Monica Pier on Wednesday morning, many people were generally unfazed by the incoming heat. Among them was David Armstrong, a tourist from London, where previous extreme heat waves have proved deadly, as they have across California.
On Wednesday, though, Armstrong said the heat gave him a good reason to escape his downtown Airbnb.
“Might as well take advantage of the circumstances,” he said. “It’s not so bad.”
Dale Frazier expected the heat wave would go mostly unnoticed, especially for those by the breezy beach, but said he was glad to finally get some real summer days.
“The summer heat has been underwhelming for beach days; I’ve hardly been able to soak it in,” Frazier said, sweating and reddening under the afternoon sun. “I’m happy I can get out like this once in a while.”
Still, Frazier acknowledged concern for his fellow Angelenos, some of whom are more vulnerable to the heat.
“I just hope homeless folks will be able to stay out of it,” he said.
But beyond the health concerns of the prolonged heat wave, it will also create conditions that experts say can fuel extreme and rapid fire growth. Mountains and foothills from San Luis Obispo County south to L.A. County, including the Antelope and Santa Clarita valleys, are under red flag warnings from Wednesday through Saturday, which means an increased risk of wildfires.
“With a low relative humidity and extreme temperatures, the fire environment will be capable of creating extreme fire behavior,” Cohen said.
Though strong winds aren’t in the forecast, according to the red-flag warnings, some local breezes are expected in the afternoons that could “exacerbate the spread of any plume-dominated fires, and add to the potentially dangerous fire-weather environment.” Fires that are plume dominated are governed mainly by the wind produced by the strong convection above the blaze, the National Weather Service says.
That fire risk could be further exacerbated by possible thunderstorms, with forecasts showing a 5% to 30% chance of the storms in the Southland from Friday through Sunday. That monsoonal pattern could bring localized gusty winds, minor flooding, debris flows in burn scars, as well as lightning that could spark fires.
Area fire departments have said they are pre-positioning resources and augmenting staffing. The California Governor’s Office of Emergency Services said it also sent additional firefighting resources to L.A. County.
“California is taking proactive steps to get ahead of upcoming fire weather,” Nancy Ward, CalOES director, said in a statement. “By prepositioning firefighting crews, equipment, and other resources in high-risk areas, we can respond faster and more effectively when needed.”
Extreme heat is also expected to scorch the desert Southwest, with highs in Death Valley reaching up to 121 degrees and Phoenix hitting 112.
By Friday, the heat wave will expand across much of the state’s interior and farther north, with the San Joaquin Valley, Sacramento Valley, parts of the Bay Area and the North Coast interior under heat advisories, with triple-digit temperatures lasting in some areas through Sunday.
Unseasonably high temperatures — and fire risk — will also be a concern through the weekend for eastern Nevada and in parts of southern Oregon. In Coos County, Ore., firefighters are already battling a high-profile fire in one of the world’s tallest trees. Crews are trying to keep flames from further damaging the Doerner fir, which stood 325 feet tall before the blaze, according to the Coos Forest Protective Assn. It has since lost its top 50 feet because of the fire, officials there said.
Although forecasters say a gradual cooldown should begin by early next week, temperatures will remain elevated — possibly through the rest of the month for the Golden State.
“Anomalous heat [is] expected to persist across nearly all of California for the rest of August,” Daniel Swain, a UCLA climatologist, wrote in a recent blog post. “Warmer than average temperatures will linger into next week and possibly beyond.”
But Frazier, on the beach in Santa Monica, isn’t too worried about more hot days.
“Keep your hats on, drink water and come to the beach,” he said, before he ran to the shoreline. “Simple and easy.”