Areas charred by last month's wildfires in Southern California now face a new threat from a powerful, but fast-moving Pacific storm. Here's what you need to know about this threat.

A strong Pacific storm with an atmospheric river will continue to pummel California with a threat of flooding rain as feet of snow piles up in the Sierra Nevada through Thursday night. Of particular concern is heavy rain raising the risk of flooding and debris flows in wildfire-scarred parts of the Los Angeles Basin.

The first storm from the tail end of an atmospheric river brought light to moderate rain throughout the Los Angeles area.

A new atmospheric river is slamming California, including fire-ravaged Los Angeles, where residents are bracing for the possibility of mudslides and landslides.

The weather phenomena are common for California winters, but they could cause dangerous debris flows or mudslides in recently burned areas.