A powerful winter storm has cut off New York City, grounding thousands of flights and straining transport networks, as 41 million people along the US East Coast brace for blizzard conditions in what could be one of the city’s worst storms on record.The storm, named Hernando, is “potentially crippling” for a lot of areas across the Northeast, said Brian Hurley, a senior branch forecaster at the Weather Prediction Center. For New York City, Long Island, New Jersey, most of Rhode Island and eastern Massachuset ...