Jun 13, 2021
An advancing cold front, along with shortwave support, created the chance for thunderstorms across the region. Sufficient shear (40kts in the 0-6km layer), moderate to high instability (1500-2000 J/kg of CAPE), and dry mid-level air resulted in damaging winds and hail. Flash flooding occurred, mostly south of Pittsburgh, with training storms.
Source: NOAA National Weather Service Storm Events Database (event 966442). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Allegheny County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.