May 8, 2009
A mature, very intense derecho moved rapidly east along a stationary front across the Mid Mississippi Valley into the Lower Ohio Valley. With a very moist and unstable atmosphere, along with strongly veering winds aloft, embedded tornadic supercells were associated with the derecho. Widespread damaging winds were the primary impact. Nearly all the damage in southern Illinois was associated with the comma head at the northern end of the bow echo. Winds were measured slightly over 100 mph under th
Source: NOAA National Weather Service Storm Events Database (event 167777). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Hamilton County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.