A flash flood warning was in effect in New York City until 9:45 p.m., and New Jersey Gov. Phil Murphy declared a state of emergency. Middlesex, Morris and Somerset counties remained under a flood warning until 7:15 a.m. Tuesday.

New York and New Jersey hit by torrential rain and flash floods, forcing highway closures, suspending subway lines and flight delays.

Heavy rain swept across parts of the Northeast on Monday night, inundating sections of New York and New Jersey with flash flooding that stranded vehicles in roadways and closed subway lines.