Apr 26, 2009
The warm front from the previous night lifted north of the state as low pressure pushed northeast out of Kansas across northwest Iowa. The atmosphere became quite unstable. Lifted indices fell to -6 to -8, with CAPE values in the 1000 to 2000 J/kg range. CAPE in the -10 to -30 C. layer of the atmosphere was between 200 and 500 J/kg. Downdraft CAPE was in the 400 to 700 J/kg range. The effective shear was between 35 and 55 kts. The freezing level was consistent with what it had been the pre
Source: NOAA National Weather Service Storm Events Database (event 156015). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Black Hawk County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.