The West Coast is braced for an atmospheric river event that threatens flash flooding and power outages from heavy rain and snow, making travel conditions hazardous or even impossible for some commuters.

Flood watches are in effect for most of L.A. County, with the possibility for flooding across the area. Schoenfeld said there’s a 30% to 50% chance of major flooding impacts in burn scar areas with concerns for mudslides, road erosion, debris flows and cars being stuck in mud.

A colossal storm is threatening to bring severe weather to much of California this week and could impact travel over the Grapevine. Here's what to know.