Parts of northern California could see up to a foot of rain, but Phoenix will remain dry and warmer than usual.

An atmospheric river is pounding Northern California with heavy rain and the threat of flooding before heading to Southern California.

Malibu's Pacific Coast Highway, which just reopened after last month's devastating Palisades Fire, is closing again Tuesday due to concerns about potential mudslides, landslides and debris flows from a prolonged atmospheric river event.