Forecasters measured 4.52 inches of rain at the Santa Barbara Airport on Christmas, beating the previous record of 2.17 inches set in 1955.

The the region's latest atmospheric storm dumped 6 inches of rain in the Los Angeles area with up to 18 inches of rain in the mountains.

The potential for flooding remains high because parts of the ground remain heavily saturated. Weather officials warn that rainfall will quickly turn into runoff.

A California storm on Christmas Eve caused flooding and mudslides, and prompted evacuations, power outages, and travel warnings as heavy rains hit the region.

More than 122 million Americans are expected to travel at least 50 miles for Christmas and New Year's holidays this year.

The National Weather Service (NWS) issued "life-threatening" flash flood warnings for parts of Southern California. Newsweek's live blog is closed.

Heavy rain and flash flooding already led to water rescues and at least one death in Northern California, local officials said. Shasta County Sheriff Michael L. Johnson on Monday declared a state of emergency to prepare for more rain and allow the state to help with hazard mitigation and search and rescue operations.

Gov. Gavin Newsom deployed 55 fire engines and rescue crews across the state during the storms and his declaration allows counties to request federal aid.

Forecasters said heavy rain was expected to drench much of Southern California through the holidays, and officials warned the storm could be deadly.