Blazes like the Creek Fire in Sylmar and the Thomas Fire in Ventura and Santa Barbara counties left many hillsides stripped bare of brush. That leaves few barriers to slow the downhill flow of water, mud and debris.
Local authorities are putting up K-rails and other barriers to divert mud flows, as homeowners also take their own steps to protect their residences.
Archie Powell has lived in Sylmar for more than 45 years and has seen his share of fires and floods. He is working hard to fill sandbags and prepare his home for the worst.
"Fire scares me. And what would happen with this frightens me," he said.
At least 1-2 inches of rain is expected in parts of Southern California. A flash flood warning is expected to go into effect Monday for Los Angeles and Ventura counties.