Aug 11, 2010
Once again the atmosphere over Iowa became very unstable during the peak heating of the day. CAPE rose to 3500-4500 J/kg by the mid to late afternoon with lifted indices of -8 to -10 C. The moisture pooled over the state with precipitable water values approaching 2 inches by evening. High temperatures reached the upper 80s to low 90s, with dewpoints topping out in the upper 70s to low 80s. The atmosphere was fairly weakly sheared with 30 kts of available shear. Downdraft CAPE was between 10
Source: NOAA National Weather Service Storm Events Database (event 240050). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Polk County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.