As millions of Americans hunker down for a massive winter storm sweeping the country, new maps are offering updated forecasts of snow and ice accumulations.

A "powerful" winter storm bringing several inches of rain is expected throughout Southern California this week, according to the National Weather Service.

Combined, the two systems are expected to produce 1-2 inches of rain in the valley and 2-5 feet of snow in the mountains, including a couple of feet in the Tahoe Basin.

A coastal flood advisory was issued by the weather service on Saturday and remains in effect through Tuesday, as up to 1 foot of inundation is possible above ground level along the San Francisco Bay shoreline.

Kyle Busch is on the pole for the NASCAR Cup season opener, which officials have moved one hour earlier than originally scheduled.

The Daytona 500 is underway, with Kyle Busch leading the 41-car field to the green flag on a sun-splashed and windy Sunday.

Zane Smith and Bubba Wallace log stage wins.