Flash Flood in Kings County, New York

Multiple cars stranded in flood waters at the intersection of Prospect Expressway and Caton Avenue.

An inverted trough extending from a low pressure system over the Western Atlantic provided a focus for persistent heavy convective rain to continually develop over the NYC metro and surrounding areas during much of the day on September 29th, 2023. In an environment with anomalously high moisture given the time of year, PWATs near 1.5-1.7 inches, rounds of heavy rainfall fell over the same areas for more than 12-18 hours. While the rainfall rates were generally 1 inch per hour or less, the persistence in the heavier rainfall resulted in a widespread total of 4-6 inches of rain with JFK receiving almost 9 inches of rain from the event. There were some brief periods of time where rainfall rates peaked at near 2 inches per hour. This resulted in widespread flash flooding across Southeast NY and Southern Connecticut.