Rain is easing after Southern California’s first significant storm of the season brought weekend downpours that aided firefighters but caused ash, mud and debris to flow across streets in wildfire-burned areas.

More rain fell Monday on parts of Southern California after causing mudflows over the weekend, helping firefighters but boosting the risk of toxic ash runoff in areas scorched by Los Angeles-area wildfires.

Scattered rain showers fell across San Diego County over the weekend, bringing some slight respite during what the National Weather Service has referred to as the driest start to San Diego's water year.

Overnight, isolated lightning strikes were reported, primarily over coastal waters and nearby land areas, but thunderstorm chances were expected to decrease by Monday morning.

Rising bacteria levels from recent rainfall has prompted an advisory for all San Diego County beaches and bays, health officials said Monday. A general rain advisory was issued, and beachgoers were warned that rain can cause runoff which raises bacteria levels in ocean and bay waters,