Flood watches are in effect for most of L.A. County, with the possibility for flooding across the area. Schoenfeld said there’s a 30% to 50% chance of major flooding impacts in burn scar areas with concerns for mudslides, road erosion, debris flows and cars being stuck in mud.

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 colossal storm is threatening to bring severe weather to much of California this week and could impact travel over the Grapevine. Here's what to know.

The storm is expected to dump 1 to 2 inches of rain along the coast and up to 4 inches in the valleys at rates that could cause problems. Some roads will be closed starting Wednesday.

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

Evacuation warnings and orders have been issued for Los Angeles communities near the Eaton, Palisades and Sunset fire burn zones ahead of the rain.