An even more potent atmospheric river-fueled storm is on a collision course with California after a first storm triggered deadly flooding and evacuations over the weekend in Northern California.

Floods turned deadly in Northern California as the latest atmospheric river slammed the region over the weekend, dropping nearly a foot of rain in some places. Meanwhile, more heavy rain and flooding are forecast to persist and expand into Southern California through the Christmas holiday week.

Drenching rain from an atmospheric river-fueled storm triggered deadly flooding and evacuations over the weekend in Northern California.

Waves of atmospheric moisture could cause urban flooding and mudslides across California this week, according to the National Weather Service.

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

Officials in Los Angeles and surrounding counties warned that the giant holiday storm could trigger "widespread flash flooding."

Two children were killed and a driver was arrested following a multi-vehicle crash on Interstate 5 on Christmas Day in northern Los Angeles County, according to the California Highway Patrol. The

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

Parts of Los Angeles County burned by wildfires earlier this year remained vulnerable to flash flooding, mudslides, and debris flows.

Towns across California have been affected by storms during Christmas week, filling homes halfway with mud, cracking highways and burying cars. The National Weather Service warned of heavy rain throughout the week due to a series of atmospheric rivers.