Jun 20, 2018
Heavy rain with little, if any, lightning moved along a stationary front in a tropical environment. Moisture was plentiful, with precipitable water values of over 2 inches. Rainfall totals reached levels that were 350% of flash flood guidance, with 1-hour rainfall totals approaching levels that were 350% above guidance and had a 0.5% annual occurrence probability. Allegheny County activated their EOC due to the flooding and severe weather. Numerous flooding incidents were reported, and approx
Source: NOAA National Weather Service Storm Events Database (event 770948). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Washington County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.