Forecasters released a breakdown Tuesday of where and when heavy rainfall this week is expected to hit areas of Southern California left burn-scarred by recent wildfires, raising the risk of potentially dangerous debris flows in those parts of the region.

Residents in burn scar areas should be ready to evacuate if needed. City and county agencies have readied streets for debris flow with K-rails and sandbags, as a storm moves in on Wednesday, Feb.

More than 100 homes were under mandatory evacuation orders in the city of Los Angeles, Jim McDonnell, the Los Angeles police chief, said Thursday morning. The Palisades fire destroyed thousands of homes in the city’s Pacific Palisades neighborhood last month, and hillsides remain vulnerable in the area.