Jun 23, 2009
A very unstable airmass was in place over Iowa during the afternoon of the 23rd. Surface temperatures soared to the low to mid 90s in most areas, with dew point temperatures in the upper 70s to mid 80s. This resulted in most unstable CAPE values of 5000-8000 J/kg and lifted indices in the -10 to -14 C range. The LCL was relatively high in the 1000-1500 meter range. Downdraft CAPE was between 1400 and 1700 J/kg and there was a significant amount of CAPE in the -10 to -30 C layer of the atmosp
Source: NOAA National Weather Service Storm Events Database (event 167055). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Dallas County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.