Cal ISO issues a statewide Flex Alert for Wednesday
Forecasters warned Tuesday that a large swath of California’s interior will experience dangerously high temperatures and the state's power grid operator called for voluntary energy conservation.
The heat spell will largely impact the Central Valley but will also extend out to interior portions of the north and east San Francisco Bay regions and to the coast south of Monterey Bay, the National Weather Service said.
The California Independent System Operator, which oversees the state's electrical grid, issued a statewide Flex Alert — a call for voluntary electricity conservation — from 4 p.m. to 9 p.m., Wednesday due to predicted high temperatures pushing up energy demand and tightening available power supplies.
On Tuesday, it topped 100 degrees in inland areas of the central coast and the San Joaquin Valley. Temperatures could reach 108 on Wednesday.
To the north, a record high of 108 was set at Ukiah Municipal Airport in Mendocino County, the National Weather Service said. It broke the previous record of 106 set in 1920.
The heat was caused by a ridge of high pressure centered over Nevada that is building westward toward the coast.
“Extreme heat will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities,” forecasters wrote.
Meanwhile the weather service issued Red Flag warnings for increased wildfire risk Wednesday in far northwest and northeast California due to dry thunderstorms with the potential for “abundant lightning.”
A heat advisory was also issued for valleys in Southern California’s inland region.