May 21, 2025
An occluding surface low slowly drifted across Ohio on May 21st. Bands of showers with embedded thunderstorms moved across southwest Pennsylvania. During the mid to late afternoon, one convective band, associated with ample 0-3km CAPE and surface vorticity, was able to generate four tornadoes across southwest PA. Three were relatively brief and weak, but one longer-track EF1 was noted in Washington County. Multiple rounds of slow-moving heavier rain also produced a number of flash flooding inci
Source: NOAA National Weather Service Storm Events Database (event 1266331). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Butler County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.