(By Steve Lyttle and Cleve R. Wootson Jr., slyttle@charlotteobserver.com and cwootson@charlotteobserver.com) The Carolinas' cold and wet winter dragged into March on Tuesday, as a storm system dropped snow and threatened to leave treacherous black ice on roadways this morning.Meteorologists said they expected snow to accumulate Tuesday night and early today - possibly several inches in some places - as temperatures fell.