ALLEN G. BREEDNEW YORK (AP) â¿¿ Forecasters say Hurricane Sandy is about 425 miles (685 kilometers) southeast of New York City and the center of the storm is expected to be near the mid-Atlantic coast on Monday night. The National Hurricane Center said early Monday that the storm has top sustained winds of 75 mph (120 kph), with higher gusts. It is moving toward the north at 14 mph (22 kph). Hurricane-force winds extend up to 175 miles (280 kilometers) from the storm's center. Sandy is on track to collide with a wintry storm moving in from the west and cold air streaming down from the Arctic. Major metropolitan areas from Washington to Boston are bracing for what is expected to be a superstorm that could menace some 50 million people in the most heavily populated corridor in the nation. THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below. From Washington to Boston, big cities and small towns were buttoned up Monday against the onslaught of a superstorm that threatened 50 million people in the most heavily populated corridor in the nation, with forecasters warning that the New York area could get the worst of it â¿¿ an 11-foot wall of water. "The time for preparing and talking is about over," Federal Emergency Management Administrator Craig Fugate said Sunday as Hurricane Sandy made its way up the Atlantic on a collision course with two other weather systems that could turn it into one of the most fearsome storms on record in the U.S. "People need to be acting now." Forecasters said the hurricane could blow ashore Monday night or early Tuesday along the New Jersey coast, then cut across into Pennsylvania and travel up through New York State on Wednesday. Airlines canceled more than 7,200 flights and Amtrak began suspending train service across the Northeast. New York, Philadelphia, Washington and Baltimore moved to shut down their subways, buses and trains and said schools would be closed on Monday. Boston also called off school. And all non-essential government offices closed in the nation's capital.