Showers and possible thunderstorms are expected to fall across Southern California Thursday and Friday, prompting a flood watch for many areas.

The region is in the grip of a muggy heat wave that will yield to monsoonal moisture early Thursday, according to the National Weather Service. Temperatures will drop significantly from Wednesday’s highs, but humidity will remain elevated, as high as 69% in Los Angeles County, forecasters said.

Remnants of Tropical Storm Mario could dump up to 2 inches of rain in some areas. A flood watch will be in effect from 5 a.m. Thursday for a wide stretch of the region, including Pacific Palisades, which was devastated by January’s wildfire.

“Localized flooding in roadways & low areas is possible & there is a 20% chc for minor debris flows from recent bur

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