Southern California was being pounded by a major storm Thursday morning, bringing evacuation warnings and feats of mudslides.

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.

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.