LOS ANGELES — On the eve of what's expected to be California's longest and most intense heat wave of the year, state electrical grid operators are warning residents to prepare for Flex Alerts and other emergency measures.
The heat wave — a result of a large dome of hot air sitting over Central and Southern California — is expected to begin Wednesday and last through Tuesday next week.
Record-breaking heat is possible Wednesday, Thursday, Sunday and Monday, according to the National Weather Service office in Oxnard.
Temperatures along the coasts could range from 80 to 95 degrees Wednesday through Saturday, before increasing up to 100 degrees Sunday and Monday, the weather service said.
The valleys and mountains could be pummeled by 95 to 110 degree temperatures Wednesday through Saturday, and highs of up to 115 degrees Sunday and Monday, meteorologists said.
For officials with the California Independent System Operator, which operates the Golden State's power grid, a lengthy and punishing period of high temperatures means Flex Alerts are likely.
"If weather or grid conditions worsen, the ISO may issue a series of emergency notifications to access additional resources and prepare market participants and the public for potential energy shortages and the need to conserve," the officials warned Tuesday night. "The power grid operator expects to call on Californians for voluntary energy conservation via Flex Alerts over the long weekend."
During a Flex Alert, consumers are urged to reduce their energy use from 4 p.m. to 9 p.m., hours when the grid is most stressed because of high demand and less available energy from solar panels.
If a Flex Alert is issued, customers will be asked to set their thermostats to 78 degrees or higher, avoid using large appliances and charging electric vehicles, and turn off unnecessary lights.
Lowering the demand on the grid can prevent further emergency measures, such as rolling blackouts, officials said.
Cal ISO said it is taking steps "to bring all available resources online," including issuing orders for restricted maintenance operations from Wednesday through Tuesday, noon to 10 p.m. each day.
Officials said they are closely monitoring conditions and will provide updates as necessary.