Some Southern California beaches have reopened after closures due to sewage and debris from the Palisades Fire, but heavy rain is forcing others to shut down.

An atmospheric river was set to begin pummeling Southern California with heavy rain on Thursday, prompting evacuations and school closures as officials warned about life-threatening flooding and mudslides in areas charred by the wildfires that broke out across the region last month.

The upcoming storm is likely to pose a higher risk for mudslides, debris flows and flooding than the rainfall this past week.