An intense atmospheric river has unleashed heavy rains across Southern California, leading to flash flood warnings and evacuation orders in various regions, including Pacific Palisades and Long Beach. With 23 million people under flood alerts, communities are urged to avoid driving as rain continues to batter the area, causing street flooding, mudslides, and road hazards. Despite a brief easing of downpours, the threat of additional rainfall persists into the coming week, raising concerns about further flooding and debris flows, especially in burn scar areas. Residents are advised to be prepared for ongoing hazardous weather conditions.