May 4, 2019
Low pressure tracked along a stalled boundary, passing through the area overnight on the 4th into the 5th. The lift associated with the low and the boundary combined with high amounts of moisture from the Atlantic Ocean and Gulf of Mexico, bringing heavy rain to the area. The rain led to several instances of flooding and even an isolated incident of flash flooding over Prince William County.
Source: NOAA National Weather Service Storm Events Database (event 825015). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Fairfax County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.