Flash Flood — Mercer, New Jersey

2021-09-01 to 2021-09-02 · near Titusville, Mercer, New Jersey

Event narrative

Widespread flash flooding occurred in Mercer County with numerous road closures and nearly 100 water rescues. There were two flood related fatalities in the county, both in Hopewell Township. Many waterways overflowed their banks including the Assunpink Creek, Stony Brook and the Delaware River (with a highly unusual quick response to the runoff).

Wider weather episode

Post Tropical Cyclone Ida brought heavy rain to New Jersey on September 1. Rainfall totals were as high as 5 to 10 inches. The heavy rain caused significant flash flooding, mainly in the northern half of the state. It resulted in widespread property damage. There were several fatalities.

View location on OpenStreetMap → (40.3319, -74.9101)

Source: NOAA Storm Events Database, event_id 985743. Narrative written by the NWS forecast office that issued the report.