Jul 11, 2019
A cold front moved into the area on the 11th, and out ahead of the boundary there was a warm and very humid airmass. The warm and humid airmass caused an unstable atmosphere which led to the development of showers and thunderstorms. Storms produced heavy rainfall, and they were slow to move due to a weak flow aloft. This led to instances of flooding and flash flooding.
Source: NOAA National Weather Service Storm Events Database (event 843242). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Harford County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.