The 12 hour Surface Analysis map shows current weather conditions ... with its use finally spreading to the United States during World War II. Surface weather analyses have special symbols ...

A procession of winter storms is forecast to bring snow, sleet, ice and potentially flood-inducing rain to sprawling bands of the U.S. this week.

As the West Coast braces for fiery winds and the Northeast shivers under a polar vortex, the nation finds itself caught between two extreme weather fronts.