L.A. prepares for weather ‘whiplash’ as sharp heat wave looms

The heat wave expected to hit the Southland this week isn’t expected to break any records, but it will make performing any normal activities outside uncomfortable.

Temperatures are expected to leap 20 degrees by the end of the week from where they were this weekend, bringing triple-digits to the Valley and sweltering heat to the rest of the region.

“It’s a little bit of a whiplash here for the weekend, compared to the last weekend,” said Bill Patzert, a climatologist for NASA’s Jet Propulsion Laboratory.

September and October are typically “heat wave months,” he said.

Hot temperatures form when high pressure from the mountains is pushed down into the valleys and stays there, keeping out ocean breezes that typically flow inland and provide relief.

Unlike the heat wave that stifled the Southland for seven days two weeks ago, the upcoming warm spell will be shorter, about four days, said Stuart Seto, a meteorologist with the National Weather Service.

The hottest day will be Saturday, when temperatures in some regions, including in the San Fernando Valley, will jump by another five degrees, hitting triple digits.

Woodland Hills, typically one of a L.A.’s hot spots, may hit 106, just shy of the record of 108 set in 1987.

The large high pressure system is expected to cover much of the Western U.S.

The hot and dry conditions, coupled with offshore winds reaching up to 40 mph, will also increase the danger of fueling rapid fire growth, forecasters said.

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