L.A. is Now Under a Heat Dome—And May Have to Get Used To It

“We’ve always had these systems, but not as frequently, not as intense and not as long-lasting,” said Bill Patzert, a retired climatologist
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California is in the middle of an intense heat wave, with the National Weather Service issuing an excessive heat warning or watch through Labor Day for many parts of the state—and some of the most extreme temperatures will be due to a “heat dome,” a curiosity that typically causes this extreme weather at the end of the summer.

A heat dome, as UCLA climate scientist Daniel Swain told the Los Angeles Times, is “a particularly persistent and strong region of atmospheric high pressure during the warm months.” Under certain conditions, that high-pressure system can trap heat—hence the dome effect.

The effects of such heat domes are worsening due to climate change.

“We’ve always had these systems, but not as frequently, not as intense, and not as long-lasting,” said Bill Patzert, a retired climatologist in the Los Angeles area.

Experts say that heat domes will make everything about extreme weather worse—from raising the chances of wildfire to worsening the drought.

“You can kind of see how that becomes self-perpetuating,” Swain said about how the weather system works to create a heat dome. “And that’s what we’re going to see this week into next week over California and Nevada. We’re going to see this persistent high-pressure system—this is a pretty extreme heat dome—that’s going to accumulate more and more heat as it persists through those processes.”

An excessive heat warning is in effect from 11 a.m. Wednesday to 8 p.m. Monday across much of Southern California, including Los Angeles County, Ventura County and the southern Santa Barbara County coast, according to the Los Angeles Times.

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