A deadly atmospheric river storm lingered over Southern California for a third day on Tuesday, soaking the region with steady rains that threatened to trigger more flooding and mudslides as the weather system slowly crept toward the Desert Southwest. As rain continued to fall throughout Los Angeles, work crews and residents were cleaning up after the storm felled more than 250 trees and triggered 300-plus mudslides across the nation's second-largest city as of Monday night, authorities said. Dow