BOSTON/NEW YORK (BLOOMBERG) - California and parts of the Pacific Northwest will wilt under near-record heat this week as a high-pressure dome builds across the region, taxing power supplies and aggravating an historic drought.
An excessive-heat watch stretches the length of California's Central Valley where temperatures could reach 109 degrees Fahrenheit (43 degrees Celsius) as soon as Tuesday (Aug 16), the National Weather Service said. A second pocket of extreme warmth is forecast for western Washington.
In a nod to the expected strain on electricity supplies, California's grid operator is asking power generators and transmission providers to hold off on any planned maintenance projects through Thursday from noon to 10pm local time each day.
The torrid temperatures also will stress one of North America's key agricultural basins, which is already grappling with the worst drought in centuries. The Central Valley's orchards, farms and vineyards are major sources of everything from almonds and tomatoes to cotton and grapes.
Spreading heat
By Wednesday, Sacramento could hit 105, just shy of a record for the date, and Redding could touch 109, which would tie the high for Aug 17, said Bob Oravec, a senior branch forecaster with the US Weather Prediction Centre.
"It is going to be well above average," Oravec said. "The heat will also eventually spread to the North-west and Northern Plains."
Power demand is expected to peak on Monday at almost 43.8 gigawatts and climb even higher over the next two days to about 45.2 gigawatts by mid-week, according to grid operator California Independent System Operator.
On-peak power prices at Southern California's SP15 hub jumped 29 per cent to average US$149.70 (S$206) a megawatt for Monday, the most since September 8, 2021. That day saw the highest demand of the year at nearly 44 gigawatts.
The all-time high of more than 50 gigawatts was set in 2006. One gigawatt is enough to power 750,000 homes in the state.
'Element of luck'
"As in every summer there has to be an element of luck in no wildfires affecting the transmission grid, no major plant outages, and no natural gas fuel disruptions," said Gary Ackerman, an independent energy consultant who founded the Western Power Trading Forum. For now, power-supply shortfalls appear unlikely, he said.
The heat wave threatens already severely limited water supplies for towns, farmers and wildlife throughout the Central Valley. The region accounts for three-quarters of California's irrigated land and produces a quarter of all US food, including 40 per cent of the nation's fruits and nuts.
Sweltering temperatures have already shrunk crops such as tomatoes and pose a health risk to farm workers and other outdoor labourers. While the heat presses down on California, the annual monsoon that has caused flooding in Las Vegas and across the South-west is expected to continue all week, Oravec said.
A patch of tropical moisture sweeping across Texas out of the Gulf of Mexico could add more energy to the storms, which have killed at least two people and flooded the Las Vegas Strip, according to USA Today.
