Torrential rains unleashed widespread flash flooding and mud flows across Southern California on Wednesday, as authorities warned motorists to stay off roads while urging residents in flood zones to evacuate or shelter in place.

Residents of Los Angeles spent the day before Christmas under rain showers and winds of around 40 mph, while the New England area braces for heavy snow later in the week.

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.

A sweeping flood watch stretching more than 800 miles along California’s coast and interior plains is in effect this week atmospheric rivers move through.

At least one person has died in Redding, California, because of the torrential rain and significant flooding as the state braces for worsening conditions this week. Redding Mayor Mike Littau confirmed the death in a Facebook update Sunday night.

Christmas week turned chaotic as a powerful storm unleashed flooding, mudslides and evacuations, triggering a state of emergency from mountain towns to major cities.

Southern California's coastal areas and valleys are forecast to get anywhere from 4 to 6 inches of rain from Tuesday through Saturday. Much of Southern California also is under a high-wind watch.

The winter storm brought heavy rain, flooding, and road closures across California. Officials evacuated people, closed major roads, and declared a state of emergency., US News, Times Now