Dangerous torrential rainfall and flash flooding are underway in the mid-Atlantic and Northeast Thursday with millions at risk along the Interstate 95 corridor. It’s shaping up to be another serious flood event in a summer that’s been full of them.

Torrential rain pummeled parts of the Northeast on Thursday, including New York City and New Jersey, stranding rush-hours passengers on a train stuck in floodwaters and inundating some roadways. Ahead of the storm states of emergencies were declared in New York City and New Jersey,

Nearly 50 million under flood threat from Virginia to Connecticut as storms hit many parts of the East Coast causing flooding and water rescues in some areas, and impacting travel. NBC News’ Erin McLaughlin reports on the very latest.

Strong rain storms lashed the U.S. East Coast Thursday, causing flash floods in some areas. As flash flooding becomes more common, experts wonder if Canadian cities are ready.

Thursday will bring the fourth day in a row with a NEXT Weather Alert for the Philadelphia region, though it will be due to storms and flooding, not necessarily the heat. It will be hot, but it won't be as hot as the previous days.

New York Governor Kathy Hochul and her acting counterpart in New Jersey said they were declaring states of emergency for areas facing the threat of extreme flash floods forecast on Thursday for much of the Eastern Seaboard.

A state of emergency was declared in both New York and New Jersey on Thursday amid severe flooding that left some neighborhoods submerged underwater. A tractor-trailer got trapped on the Clearview Expressway near Northern Boulevard in Queens.

Flooding in New York City created a waterfall in the underground tunnels of the subway system on Thursday (July 31). New York Governor Kathy Hochul and her acting counterpart in New Jersey said they were declaring states of emergency for areas facing the threat of extreme flash floods forecast for much of the Eastern Seaboard.