US-WEATHER-STORM-WHITE HOUSE

A woman walks down Pennsylvania Avenue near the White House as snow falls on March 6, 2013 in Washington, DC. A winter storm warning remains in effect until early Thursday. A massive winter storm pounding the northern United States Tuesday grounded 2,600 flights, closed hundreds of schools and made roadways and highways impassible. At least four people were reportedly killed in accidents on icy and snow covered roads and highways. More than a dozen states from Minnesota to Virginia were in the path of the huge storm, which had already dumped as much as two feet (60 centimeters) of snow in Montana and 15 inches (38 centimeters) in North Dakota. AFP PHOTO/Mandel NGAN (Photo credit should read MANDEL NGAN/AFP via Getty Images)