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

More than 50 million Americans across the East coast were hit with torrential downpours and flash floods overnight with New Jersey now under a state of emergency.

Center Valley, where flooding was reported along Route 309, had a recorded 6 inches of rainfall, making it the highest rainfall total in the Lehigh Valley, according to the National Weather Service in Mount Holly, New Jersey. Other areas had about 1 or 2 inches of rain.

Heavy rains during the evening brought flooding, road closures and power outages throughout New Jersey, which is under a state of emergency.

Severe storms hammered parts of the tri-state area Monday afternoon into the late evening hours, flooding City subways, prompting dozens of water rescues and triggering a state of emergency in hard-hit parts of New Jersey.

Flooding was particularly high in Central Jersey along the Route 22 corridor in Watchung, Plainfield and North Plainfield.

The National Hurricane Center said July 14 it is tracking a system off the Atlantic coast of Florida that could bring heavy rain to the area.

“When heavy rainfall overwhelms our infrastructure and the ground’s natural ability to absorb water, we see rapid rises in water levels in rivers, streams & underground springs we never notice,” DEP Commissioner Shawn LaTourette tweeted. “When 16% of your State lies in a floodplain, that is an emergency.”

New Jersey is expected to miss the heaviest rainfall in the latest round of thunderstorms on Tuesday, but more flash flooding is possible.

Tuesday in the Philadelphia region will be another day with the risk of some heavy rain and storms, but it shouldn't be quite as widespread and heavy as it was on Monday.

Tuesday’s forecast for Royal Portrush will likely serve as a preview for the rest of the championship rounds – outbreaks of rain amid some sunny spells.

Heavy rain caused flash flooding and road closures around the Lehigh Valley on Monday evening as storms made their way through. More rain is expected this week.