India, Jan. 26 -- A massive winter storm set the stage for a brutal travel day on Sunday, with airlines warning of widespread cancellations and delays at some of the nation's busiest airports. Widespread snow, sleet and freezing rain threatened nearly 180 million people - more than half the US population - in a path stretching from the southern Rocky Mountains to New England, the National Weather Service said Saturday night. After sweeping through the South, forecasters said the storm was expected to move into the Northeast, dumping about 1 to 2 feet (30 to 60 centimetres) of snow from Washington through New York and Boston.

More than 13,500 flights have been cancelled across the US since Saturday, according to flight-tracking site Fligh...