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.

Rain was falling across Southern California on Sunday, bringing some relief to thousands of firefighters battling multiple major blazes for nearly a month in the Los Angeles area, but also prompting new threats of floods and mudslides across burn-scarred lands.

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.