The National Weather Service Forecast Office in New York, NY provides official forecasts and warnings for New York City, Long Island, the Lower Hudson Valley of New York, Northeastern New Jersey, Southern Connecticut and the surrounding Coastal Waters. A giant wave crashed over New York 2,300 years ago, scientists claimed yesterday. WAVES up to 80ft (25 metres) high could destroy New York and Miami in a mega-tsunami if a landslide takes place in Spain, an expert claims.