Flood in Northumberland County, Pennsylvania

Heavy rainfall led to 2 to 3 feet of standing water on a roadway, with vehicles stranded in Northumberland borough.

A warm front approaching central Pennsylvania in an environment of sufficient instability and shear allowed for thunderstorm formation during the late afternoon and evening hours, with multiple rounds of severe thunderstorms crossing the northern tier of Pennsylvania. The multiple rounds of heavy rainfall, coupled with local topography, allowed for flash flooding across hydrologically sensitive areas of Potter and Tioga counties. As thunderstorms progressed southward into the Lower Susquehanna Valley, they began to congeal into a line of thunderstorms producing more widespread wind damage.