California will again be in the crosshairs of a dangerous and potentially historic heatwave over Labor Day weekend, prompting officials to warn of an increased fire hazard and set off a flex alarm in hopes of relieving the state's power grid.
Forecasters say the weather system will bring temperatures higher than the August heat wave and potentially a number of record highs.
Most of the state will be in heat wave as of Friday. In some areas of Southern California, weekend temperatures are projected to rise 15 to 20 degrees above normal or even above normal.
"I'm going to British Columbia personally," joked David Sweet, a meteorologist with the National Weather Service in Oxnard.
Except for some northeastern areas, virtually all of California will be exposed to excessive heat monitoring or warning from Friday or Saturday through Sunday or Monday.
The high temperatures will increase the risk of power outages and major fires, unwanted news after the double blow of power outages and a historic firestorm during another heat wave a few weeks ago.
The Californian independent system operator, who runs the electricity network for most of the state, issued a nationwide flex alarm on Thursday calling for voluntary electricity savings from 3 p.m. to 9 p.m. Saturday to Monday.
Today will be the last day with tolerable temperatures before the heat rises this weekend. Get out there and soak up the September sun before it gets too hot! Maybe buy an ice cream and popsicle to keep you cool! #CAwx #LAheat #heatwave pic.twitter.com/cjA7Chz1eO
– NWS Los Angeles (@NWSLosAngeles) September 3, 2020
If there's a silver lining, that heatwave, while intense, is not as long-lasting as the one that brooded the state in mid-August.
Temperatures will rise on Friday and rise on Saturday and Sunday before falling on Monday.
"Saturday and Sunday will be the hottest days, but Monday will still be hot as hell," said Samantha Connolly, a meteorologist with the National Weather Service in San Diego.
After that, temperatures will continue to decline and, according to Sweet, return to normal by the end of next week.
"It's a shorter length of time, but it'll be hotter than the last," he said.
On Sunday, which is expected to be the height of the heat wave in many areas, the mercury in downtown Los Angeles is likely to be above 100 degrees. Some of Los Angeles County's inland valleys will exceed 110, with Woodland Hills expected to reach 116.
Although the coastal areas are cooler, they can still see temperatures above 90 degrees.
"The entire region will face an excessive heat warning at some point," Connolly said.
Have we screamed enough over the heat? There is now an excessive heat warning for Fri-Mon. Have you started drinking water yet? While it's a bummer, outdoor activities should be limited on this holiday weekend, especially during the hottest part of the day. pic.twitter.com/dOZX3weXgw
– NWS San Diego (@NWSSanDiego) September 2, 2020
Both Connolly and Sweet said the heatwave could rewrite the record books for much of the state. Some of the cities that could see new daily highs over the weekend are Long Beach, Camarillo, Paso Robles, Riverside, Anaheim, and Escondido.
Connolly noted that it is expected to be less humid than it was during the previous heat wave, which means that while conditions are warmer, they may not feel as oppressive.
"It looks like most of the state is seeing this heat," she said.
To reduce the load on the electricity grid, Cal-ISO recommends residents stop using large appliances, turn off unnecessary lights, close blinds and curtains, and set thermostats to 78 degrees while the Flex alarm is activated.
Forecasters also said residents need to avoid the heat as much as possible.
"We encourage people to suspend their plans for prolonged exposure to daytime heat, as heat illness can affect anyone, especially young children and the elderly," Sweet said. "So if you have older neighbors, you want to check them out."
Sweet also said residents should stay indoors if they can, preferably somewhere with air conditioning and drink plenty of fluids.
With the holiday weekend coming up, he said, “We recommend water, not alcohol. Alcohol will dry you out. "