The first significant storm of the season brought snow and downpours to Southern California that doused wildfires and caused some ash and mud to flow across streets in the Los Angeles area on Monday.

Heavy rain beginning Sunday afternoon caused some mudslides, and snow closed part of Interstate 5 near Los Angeles.

Because of the recent wildfires, parts of Southern California are vulnerable to mudslides, mudflows, and landslides. Ash and debris are created when trees and other objects are burned in wildfires, and this can cause the ground to become slick.