Sep 10, 2020
Showers and thunderstorms developed across Long Island and portions of New York City during the early morning hours in association with a surface trough south of the area. With weak steering flow and high moisture content (precipitable water values 2+ on the Upton, NY sounding), this resulted in flash flooding across portions of Nassau and Suffolk Counties. While rainfall totals averaged 1-2 inches across New York City and Long Island, portions of southern Nassau County and southwestern Suffolk
Source: NOAA National Weather Service Storm Events Database (event 918257). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Nassau County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.