Southern California could get as much as 6 inches of rain in the mountains and 3 inches in coastal areas and valleys before the system moves out.

Officials in California distributed sandbags, prepositioned rescue swimmers and told residents to have their go-bags ready as the state prepares for an atmospheric river that could bring heavy rain, winds and flooding to areas recently ravaged by wildfires.

Snow and ice in whiteout conditions contributed to a pileup of as many as 30 cars on a major highway connecting Oregon and Idaho, reportedly injuring several people, as a winter storm descended on the Pacific Northwest.