Flash Flood — Lancaster, Pennsylvania

2025-09-23 · near Lancaster, Lancaster, Pennsylvania

Event narrative

Multiple reports of water across the roadway resulted in the closure of New Holland Avenue between Lancaster and Eden.

Wider weather episode

Daytime heating during the afternoon and evening hours of September 23, 2025 allowed for convection to occur across portions of the Lower Susquehanna Valley in an environment with ample moisture and low steering flow aloft allowing for slow-moving thunderstorms. Thunderstorms produced a quick 3 to 4 inches of rainfall in Millersville, which prompted multiple instances of flash flooding in the vicinity of Millersville University.

View location on OpenStreetMap → (40.0511, -76.2899)

Source: NOAA Storm Events Database, event_id 1289346. Narrative written by the NWS forecast office that issued the report.