A winter storm blew out of the Midwest and zeroed in on the middle Atlantic region from New York to Washington, D.C., where snow and wet roads slowed rush-hour traffic and emergency shelters were opened for the homeless. By late in the day snow was falling in lower Michigan, eastern Indiana, Ohio, northern West Virginia, northern Virginia and western Maryland, Pennsylvania and New York. Rain fell from the central Atlantic coast to Georgia, and winds gusted to 97 m.p.h. at Flat Top Mountain, east of Asheville, N.C., the National Weather Service said. The Grandfather Mountain resort in western North Carolina was battered by winds of more than 100 m.p.h., a spokesman said.