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.

The storm, which forecasters said could produce tornadoes, is expected to strengthen Friday and move towards the central US.

California braced for the arrival of a massive storm on Wednesday, evacuating residents in areas at risk of mudslides and debris flows.