Chain controls have been in effect on both Highway 50 and Interstate 80 in the Sierra since Wednesday and remain up as of Thursday morning. Drivers were urged to avoid traveling up the mountain for the time being. Travel on 80 was also closed to all semi-trucks and trailers for the time being between Applegate and the Nevada state line.

A Severe Thunderstorm Warning has been issued for east central Ventura County and northwestern Los Angeles County until 8:30 a.m.

A Tornado Warning has been issued for parts of Santa Cruz County on Christmas, the National Weather Service said. The warning includes Santa Cruz, Scotts Valley and Capitola until 1 p.m. Aviso de Tornado incluye Santa Cruz CA, Scotts Valley CA, Capitola CA hasta la 1:00 PM PST pic.twitter.com/BuaaTIWxx2

The National Weather Service said two more impulses will move through the area with the potential for flooding in the burn scar areas.

The second wave of the holiday storm in Southern California is expected to intensify during the afternoon hours on Christmas Day.

A storm that moved into Northern California overnight is resulting in power outages, flooded roads and downed tree limbs.

An emphasis has been placed on burn scar areas that are more susceptible to flooding, mudslides and debris flows.

A powerful storm carrying a strong atmospheric river laid siege to California Wednesday, with evacuations issued because of the risk of life-threatening flooding and debris flows. The National Weather Service is warning of more flooding rains and strong winds in Northern and Southern California on Christmas Day.