LOS ANGELES (CBSLA.com) – A statewide Flex Alert will be in effect again Wednesday afternoon and evening as a heat wave continues to grip Southern California.
The California Independent System Operator, which manages the statewide power grid, issued a Flex Alert for 2 p.m. to 9 p.m. Wednesday, the same period as Tuesday’s alert.
A Flex Alert is issued when the electrical grid is “under stress,” generally from increased power usage due to hot weather.
As part of the alert, residents were urged to make an extra effort to conserve power during late afternoon hours, when air conditioners tend to be used most. The agency predicted peak usage on Wednesday would exceed 46,600 megawatts, and noted that widespread air-conditioner use can put strain on the electrical system.
According to Cal-ISO’s website, electrical demand late Tuesday afternoon topped 44,000 megawatts. The highest demand ever recorded by the system was 50,270 megawatts, which occurred on July 24, 2006.
An excessive heat warning will remain in force until 9 p.m. Wednesday in the San Gabriel Mountains, where temperatures of between 100 and 105 are expected, and in the Antelope Valley, where highs are expected to range between 106 and 110 through Friday.
A less serious heat advisory will be in force until 9 p.m. Wednesday in the Santa Monica Mountains Recreational Area and the Santa Clarita, San Fernando and San Gabriel valleys. The advisory, issued Wednesday, was allowed to expire in Los Angeles proper and beach cities.
Forecasters have warned of a new wrinkle in the heat wave beginning Thursday, saying onshore winds will combine with high heat, low humidity and dry vegetation to create a “risk of extreme fire behavior.”
As a result, a fire weather watch issued by the National Weather Service, often a precursor to a red flag warning, will be in effect in Los Angeles County in the San Gabriel Mountains and the Antelope Valley from Thursday morning through Thursday evening.
“If fire ignition occurs, conditions may be favorable for extreme fire behavior, which would threaten life and property,” an NWS statement said.
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