High humidity levels, summer heat and long days will combine to produce conditions favorable for drenching thunderstorms leading to additional flash flooding in the coming days in many parts of the U.

Flooding caused delays on multiple New York City subway lines Monday as torrential rain pummeled the Tri-State Area.

Flash floods are occurring across the U.S., from Texas to New Jersey. Here's what you should know as risks escalate.

The heavy downpours wreaked havoc across the city with footage showing commuters overwhelmed by floodwaters in various subway stations.

Severe flash flooding struck New York City, Westchester County, Staten Island, and Rockland County, Bergen, Essex, Hudson, Passaic

While FEMA has improved the accuracy and accessibility of the maps over time with better data, digital tools and community input, the maps still don't capture everything.

The warning was in place for Ocean County. "The heavy rain has ended. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures," states the National Weather Service.