A major storm was expected to bury the Washington region Saturday with what forecasters said could be the largest snowfall to hit the area in six years and the greatest December accumulation in more than 70 years. Accumulations of 15 inches or more in the city and up to 24 inches in parts of the Blue Ridge Mountains were possible, according to the National Weather Service. The snow was expected to cause significant disruptions for shoppers, travelers and revelers on the last weekend -- and biggest shopping day -- before Christmas. Especially large amounts of snow could accumulate southeast of...