After this week's big warm-up it's hard to believe that we are back to fullproduction on snowfall maps, but so goes the weather. The atmosphere is alwaysfull of surprises, and that's what makes being a student of the weather sointeresting. It's like a wonderful storybook. There is always a new chapter tobe told.Chapter one is our latest interpretation on how the winter storm will unfoldover the weekend. Knee-deep snow has already fallen in the Sierra Nevada, andthe snowstorm spread into the mountains of Southern California Fridayafternoon. This will cause very slow going over the passes into and out of LosAngeles during the overnight hours.

The map above shows the entire scope of the snowstorm through the Westernmountains Friday night and Saturday. Below you can see how the winter stormwill impact the Plains and Midwest during the second half of the weekend.

Snowfall for the Northeastern states (yes, it's going to happen) will be shownin future AccuWeather.com reports.

Story by AccuWeather.com Senior Meteorologist John Kocet.