At least some debris flow is ongoing in the Malibu area, with portions of the Pacific Coast Highway closed. The same storm system driving severe weather elsewhere in the country is fueling one of the most widespread and potent rounds of rain in Southern California since the historic January fires.

A flood watch will go into effect Wednesday afternoon across much of Los Angeles and Ventura counties as weather officials warn about heavy rainfall and debris flows. The National Weather Service has issued a flood watch from Wednesday evening until Thursday afternoon.