A powerful storm dropping drenching rain on flood-prone Southern California is raising concern among forecasters that it could produce a dangerous, widespread outbreak of tornadoes, damaging winds and fires along with a blizzard as it crosses the entire United States in the coming days.

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

Incoming heavy rain from an atmospheric river-fueled storm that slammed into the West Coast early Wednesday is threatening mudslides and debris flows in Southern California and has already prompted evacuations in the Los Angeles area.