Flash Flood — Allegany, New York

2025-06-09 · near Wellsville, Allegany, New York

Event narrative

Flooding reported on O Connor Road.

Wider weather episode

Strong to severe thunderstorms developed along a cold front and within the warm sector of an approaching system. Favorable shear, along with forcing from the cold front helped to develop severe storms that also resulted in a confirmed tornado in the western Southern Tier. Additionally, a very moist atmosphere was present within the systems warm sector, helping to contribute to heavy rainfall with showers and thunderstorms. Some of the heavy rain that developed across the western Southern Tier, combined with antecedent conditions caused flash flooding in Allegany County.

View location on OpenStreetMap → (42.1302, -77.9522)

Source: NOAA Storm Events Database, event_id 1273555. Narrative written by the NWS forecast office that issued the report.