FloodZoneMap.org

Flash Flood — Polk, IA

Jun 12, 2002

A complex weather situation unfolded during the day on the 12th with a series of events coming together. The forest fires in Colorado were a contributing factor to the thunderstorm initiation. During the night of the 11th and early morning of the 12th, two mesoscale convective systems formed over the fires in Colorado and tracked across Kansas. By sunrise on the 12th, the outflow from one of the complexes pushed north into northern Kansas and Southern Nebraska to interact with a quasi-station

Source: NOAA National Weather Service Storm Events Database (event 5294321). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Polk, IA

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.

View Polk County flood data →

More Flood Stories

Flash Flood1 death$100K damage

Polk, IA · 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.

Read the full account →
Flash Flood1 death$1.0M damage

Polk, IA · Jun 30, 2018

A frontal boundary was draped across areas just west of Iowa during the morning hours of June 30th, and slowly moved eastward into the state throughout the day.

Read the full account →
Flash Flood1 death$30K damage

Polk, IA · Feb 19, 1997

Significant ice jams took place along the Raccoon River along its lower reaches. One occurred where the river flows through a gravel pit on the west side of the Des Moines area. A woman was driving across a flood plain road when one of the ice jams suddenly broke.

Read the full account →
Flash Flood$20K damage

Polk, IA · Jul 20, 2025

Diurnally driven afternoon storms on Sunday, July 20th, 2025, developed within an unstable environment with CAPE values over 3000 J/kg and 40 to 45 kts of effective shear.

Read the full account →