Southern California is expected to experience extreme heat through the weekend, a situation that typically puts a strain on the grid as air conditioners work overtime, particularly during peak afternoon hours.
The California Independent System Operator issued the first Flex Alert for Friday afternoon, calling on Californians to save power between 4 p.m. and 9 p.m. It was extended to a second day through Saturday for the same time period.
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An excessive heat warning will be in effect in the Antelope Valley through 9 p.m. Monday, with the National Weather Service predicting "dangerously hot conditions with temperatures up to 113 expected."
Forecasters said temperatures won't drop dramatically overnight in the area, with lows expected in the mid-70s to mid-80s.
WATCH: Extreme heat hits Antelope Valley as CA power grid declares Flex Alert
"Strong upper level high pressure will bring excessively hot temperatures to the interior valleys, mountains and deserts through early next week, with above normal temperatures most everywhere away from the coast," according to the NWS.
Forecasters said the excessive heat warning could potentially be extended to the Santa Clarita Valley on Friday and beyond, depending on how the high-pressure system unfolds. For the time being, the NWS issued a less severe heat advisory for the Santa Clarita Valley that will be in effect from 10 a.m. Friday until 9 p.m. Sunday, with temperatures up to 105 degrees expected.
A heat advisory will be in effect through 9 p.m. Monday for Los Angeles County mountains, excluding the Santa Monica range. Forecasters said lower elevations could see temperatures of up to 106 degrees.
City News Service contributed to this report.