LOS ANGELES (CBSLA.com) — A flash flood warning was issued Wednesday for parts of the Southland.

The National Weather Service said a combination of high heat and subtropical moisture has created instability, raising a chance for showers and thunderstroms.

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The flash flood watch will be in effect from 10 a.m. through Wednesday evening fro the San Gabriel Mountains and the Antelope Valley.

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Campers and hikers were urged to be aware of conditions and pay attention to weather forecasts.

In the event of a thunderstorm, “expect dangerous cloud-to-ground lightning, gusty erratic winds …, small hail and brief heavy downpours, which could cause flooding across low-lying areas well as washes and arroyos,” the NWS warned in a statement on its website. “If you approach moving water across the highway, turn around. Don’t drown.”

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