Evacuation warnings remained in effect Wednesday in the Highland area as a storm's most powerful round was set to wallop Southern California.

A flood watch has been issued for much of Southern California and will remain in place through Thursday afternoon.

Heavy rain has fallen in the overnight hours across Southern California, prompting evacuation and flood warnings for wildfire burn zones.

An atmospheric river began hammering down in Southern California, bringing heavy rain and triggering mandatory evacuation orders in some areas.