New York City warns of possible flash floods as thunderstorms develop along East Coast

Federal forecasters issued flood alerts for 39 million people late Saturday into Sunday as a line of thunderstorms developed from Washington, D.C., to New Haven, Connecticut. New York City Emergency Management warned residents of heavy rain and possible flash flooding into Sunday morning as the city opened 51 weather shelters for those vulnerable to floodwaters, including people in basement apartments. The National Weather Service issued a slew of flood alerts, including flood watches, late Saturday through early Sunday for parts of Maryland, Pennsylvania, Delaware and New Jersey. A flood watch for Washington, D.C., expired at 1 a.m. Sunday. Philadelphia and neighboring counties were under a flood watch through the morning. A flood watch for New York City was scheduled to start at 4 a.m. Sunday and extend through noon.