A flood watch remains in effect Thursday for parts of Southern California as the region experiences rainfall and flooding conditions.

The strongest wave of a powerful winter storm reached Southern California overnight, bringing flash flood warnings, dropping snow levels and a possible tornado.

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.