Event Summary

A combination of a pre-frontal trough and a passing cold front triggered several severe thunderstorms across the Lower Hudson Valley, New York City, and Long Island. Nickle size hail was reported at Rockefeller Plaza. Quarter size hail was reported covering the ground at West Broadway and Spring Street. Quarter size hail was reported just west of Jamaica Station. A cold front approaching from the northwest and nearly parallel to the wind flow aloft triggered training thunderstorms which produced heavy rainfall and resulted in flash flooding in Queens, New York (Manhattan) and Nassau counties. Heavy rain caused flooding across the FDR Dr. between 34th St. and 96th St. in Manhattan. Heavy rain caused flooding on the Grand Central Pkwy eastbound at the Brooklyn-Queens Expressway exit.