Parts of New York City and Northern New Jersey were inundated on Monday night as widespread thunderstorms moved through.

Two people were killed in New Jersey following flash flooding in the northeastern United States that caused travel chaos, authorities said Tuesday, as the region braced for more heavy rain.

The National Weather Service released a flood warning at 9:51 p.m. on Monday in effect until Tuesday at 1 a.m. for Essex, Passaic and Union counties.

Torrential downpours battered the New York metropolitan area on Monday night, unleashing widespread flash flooding that brought transit systems to a standstill, submerged roads and highways, and disrupted air travel across several major airports.

As the skies opened up over New York City, torrents of rain transformed bustling streets into rivers, leaving residents grappling with an unexpected deluge.

Forecasters say some thunderstorm cells have the potential to dump as much as 2 to 3 inches of rain in one hour, posing a risk of rapid flooding.

The tornado warnings in Atlantic and Ocean counties in New Jersey are no longer in effect on Wednesday night. Earlier Wednesday, a tornado warning in New Castle County, Delaware, expired at around 9:15 p.m. A severe thunderstorm watch was in effect across much of the Philadelphia region for Wednesday evening.