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.

Several areas in Southern California could have scattered showers throughout the day, but the potential for "damaging flooding" will not increase until the evening to overnight hours.