LOS ANGELES– Californians tried to ride out the extremes of a changing climate on Friday as a punishing heat wave that helped fuel deadly wildfires pushed the state to the brink of blackouts for a 10th day back-to-back as a tropical storm hit the shore with the promise of cooler temperatures but also possible flooding.
The abrupt change in conditions surprised even weather junkies.
“This may be the most unusual and extreme weather week in California in quite some time – and that’s saying something. Phew,” Daniel Swain, a climatologist at the University of California, Los Angeles, wrote on his Western weather blog.
While the rains may be welcome in a drought condition and will bring relief with more normal temperatures, more brutal deluges and heat waves are expected to become regular features as climate change warms the planet and disasters related to weather conditions become more extreme.
“We will see these heat waves continue to get hotter and hotter, longer and longer, more and more wildfire-ridden,” said Jonathan Overpeck, dean of the environment and development faculty. sustainability from the University of Michigan. “The chances of really intense rainfall are increasing. And that is why we are concerned about the flooding associated with this remnant hurricane.
California is just the latest victim in a year of sometimes deadly heat waves that began in Pakistan and India this spring and swept through parts of the northern hemisphere, including China, Europe and other parts of the world. other parts of the United States.
Climate change has also exacerbated droughts, dried up rivers, intensified wildfires and, conversely, led to massive flooding around the world as moisture that evaporates from land and water is retained in the atmosphere, then redeposited by intense rains.
Scientists are hesitant to attribute a specific weather event, such as Hurricane Kay, now downgraded to a tropical storm as it heads toward California, to global warming. But they say heat waves are exactly the type of change that will become more common.
The so-called heat dome that baked California was blocked by a region of exceptional high pressure over Greenland, of all places, which essentially created a weather traffic jam, said Paul Ullrich, professor of modeling from the regional climate at the University of California, Davis. This stopped the high pressure system that was forcing warm air over California from moving.
A marquee outside an old theater in Los Angeles’ Chinatown said: “Satan has called. He wants to find his weather.
Temperatures hit a record high in Sacramento of 116 degrees (46.7 C) on Tuesday. Many other places set records for September and even more set daily records.
The heat that has colored the weather dark red for more than a week in California is just a preview of the attractions to come.
Sacramento, the state capital, has about 10 “extreme heat” days a year and that will double again by mid-century. In the 1970s, the city had five, Ullrich said.
“That’s going to be pretty much the story for a lot of the Central Valley and a lot of Southern California,” Ullrich said. “This kind of exponential growth in the number of extreme heat days. If you combine all of that, you end up with heat waves like the ones we’ve been experiencing.
For nine days until Thursday, the vast energy network that includes power stations, solar parks and a network of transmission lines was strained by record demand driven by air conditioners.
“If we’re going to build a statue for someone in the West, it’s going to be a Willis Carrier,” Bill Patzert, a retired climatologist at NASA’s Jet Propulsion Laboratory, said of the inventor of the air conditioner. “Very large areas of Southern California would be essentially unlivable without air conditioning.”
Air conditioning puts the greatest strain on power sources during a heatwave and power grid operators have called for conservation and warned of the threat of blackouts as usage hits a low. record on Tuesday, surpassing a record set in 2006.
The state may have averted a repeat of the rollout blackouts two summers ago by sending out a first-ever text alert that rang out on 27 million phones urging Californians to “take action” and cut off non-essential power. Enough turned on thermostats, turned off lights or unplugged appliances to avoid power outages, although thousands of customers lost power at various times for other reasons.
The West is in the grip of a 23-year-old mega-drought that has nearly drained reservoirs and jeopardized water supplies. This, in turn, has led to a sharp decline in the hydroelectricity that California relies on when electricity demand is peak.
“The part of the country that is most affected is the southwestern and western United States,” Overpeck said. “It’s a global poster child for the climate crisis. And this year, this summer, it’s really been the northern hemisphere that’s just been an exceptionally hot, wildfire-ridden hemisphere.
The extreme heat helped fuel deadly wildfires at both ends of the state as the flames fed on grass, brush and wood already “preconditioned to burn” by the drought, then pushed by the wave of heat, Overpeck said.
Firefighters have struggled to control major wildfires in Southern California and the Sierra Nevada that have exploded into growth, forced thousands to evacuate and produced smoke that could interfere with solar power and further hamper the electricity supply.
Two people were killed in the fire that broke out last Friday in the northern California community of Weed at the foot of Mount Shasta. Two others died trying to flee in their cars a fire in Riverside County that threatened 18,000 homes.
What’s left of the hurricane is expected to bring heavy rain and even flash flooding to Southern California Friday night through Saturday. Strong winds could initially make it difficult and dangerous for firefighters trying to get the blazes under control, Patzert said.
Heavy downpours could also trigger landslides on mountainsides charred by recent fires. While several inches of rain could fall, much of it will run off the arid landscape and not make a dent in the drought.
“It comes at you like a fire hose and you try to fill your champagne glass,” Patzert said. .’”