Rain on the way to parched Southern California on Saturday will aid firefighters mopping up multiple wildfires.

Rainfall has provided relief to wildfire-stricken Southern California but posed new threats of toxic ash runoff and debris flows. Authorities are expediting cleanup efforts and implementing flood-control measures to mitigate environmental impacts.

California's deadly wildfires could come to an end in the coming days when a weekend storm douses historically dry terrain, but the storm will come with the potential for a different problem: flash floods.