ROLLING BLACKOUTS AS BAY AREA SIZZLES
Scorcher: Record high temperatures might last 10 days
The heat wave that steamrolled into California Friday is by all appearances the beginning of a potentially dangerous hot spell — the demon child of climate change — that experts say will grip the West in a sweltering blanket and worsen the impact of the coronavirus pandemic.
Heat records were shattered across the Bay Area, with many cities hitting levels 10 degrees above previous highs for the day. The thermometer even briefly hit 90 degrees at Half Moon Bay’s airport — 30 degrees above what had been recorded in the coastal spot just two days before.
“This is an extreme event,” said Will Pi, a meteorologist for the National Weather Service in Monterey. “It’s
something that doesn’t usually occur in your area until well into September.”
The high temperatures are expected to linger over California and much of the southwest for the next seven to 10 days. This would make it the biggest, longest hot spell to hit the state in many years, according to Daniel Swain, a climate scientist at UCLA and the National Center for Atmospheric Research.
“This event will likely have wideranging impacts, from human health, wildfire, and electricity demand perspectives,” Swain wrote in his Weather West blog. “I suspect this event will probably end up being one of the most significant widespread California extreme heat events in the past decade, if not longer.”
The first day already is one for the books.
The recorded high for San Francisco was 95 degrees, well above the 86 degrees recorded for August 14 in 1995. Santa Cruz reached 105 degrees, breaking the previous record of 96 degrees that had been in place since 1906.
Other broken records dated only to 2019, an ominous hint of climate change’s possible impacts. Downtown Oakland hit 90 degrees — 10 degrees above last year’s recordsetter — and it was 102 degrees in Redwood City. Santa Rosa reached 106 degrees, 5 degrees above last year. Napa’s high was 104 degrees.
The blistering heat is being held in place by a ridge of high pressure that has strengthened over the past few days, according to meteorologists. Making things worse, a mass of humid air from Hurricane Elida in the Pacific has moved over California and is locked in place.
“Usually this time of year you have sea breezes that keep things cool” along the bay, Pi said. “The tropical moisture is keeping them out.”
It also could cause isolated thunder and lightning storms to strike Northern California, increasing the fire danger.
Swain said the unusual humidity will make it harder for people to cool off, with very little drop in temperatures overnight. That, he said, could cause problems for sick, elderly or isolated people without air conditioning.
“When you do get these excessive overnight temperatures in places where people don’t have air conditioners, that actually becomes rather dangerous,” Swain said.
Not surprisingly, some Bay Area residents looked to shorelines for relief.
This includes Oakland residents Julia Hamilton and Tanaya Reid, who fled their “hotbox” apartments to Alameda Beach,where entire families bobbed up and down in the water.
“We both live in studio apartments, and my tiny studio is like a hotbox,” Reid said. “I just could not stand it.”
It was roasting by noon Friday at Lafayette Reservoir, where only a few people braved the tripledigit heat.
Iris Lepe, 28, arrived with a blanket and a book to read by the water.
“It seems like a crazy day to pick, the hottest day of the year,” said Lepe, a DoorDash deliverer who has tried to avoid outings to such crowded places during the pandemic. “But actually I thought it might be the best day, because the heat might keep people inside.”
Leah Roth and her daughter marveled at the heat as they retreated to their car with their water bottles after a hike. Roth, a nurse, said she worries most about elderly people without air conditioning.
“I just hope everyone is hydrating and staying safe,” she said.
It is a legitimate concern, said Noah Diffenbaugh, a climate and environmental scientist at Stanford University, pointing to several studies showing that elderly and infirm people suffer more health problems and die more often during high heat and humidity.
Extreme weather also has a more severe impact on minority and underprivileged communities, he said, because residents often can’t afford air conditioning, are isolated and don’t have access to many health or emergency services. Lowincome, urban communities often have few shade trees. And because asphalt absorbs solar radiation, it exacerbates the heat.
The problem is, in some ways, our own fault, he added, because extreme heat like this is “very consistent with what’s been predicted for decades to result from global warming.”
“This is a region where we have strong evidence from observation and climate model experiments that there is a rising risk of recordsetting heat,” he said. “That risk is continuing to intensify as a result of the global warming that has already happened.”
It is particularly worrisome with the coronavirus shelterinplace continuing and fire danger increasing across the West, he and other scientists said. Those who are not sweating at home are likely to be heading out to the beaches, raising concerns about a lack of social distancing and the spread of the coronavirus.
And there is more to come over the next 10 days, according to the National Weather Service. A brief coolingoff period is expected at the beginning of next week, but then temperatures are going to get even hotter, forecasters predict.
Swain said places like Concord, Livermore and Sacramento could see temperatures topping 110 degrees several days in a row.
That’s really, really high.” he said. But “the duration (of the heat wave) is expected to be ... the most extraordinary thing.”
Peter Fimrite, Brett Simpson and John King J.D. Morris are San Francisco Chronicle staff writers. Email: pfimrite@sfchronicle.com, brett.simpson@sfchronicle.com, jd.morris@sfchronicle.com, jking@sfchronicle.com. Twitter: @pfimrite, @brettvsimpson, @thejdmorris @JohnKingsfchron