Storm Events Database

Event Details

Event Flash Flood
-- Flood Cause Heavy Rain
State IOWA
County/Area GRUNDY
WFO DMX
Begin Date 08/10/2010 23:55:00 CST-6
Begin Range 3
Begin Azimuth NW
Begin Location FERN
Begin Lat/Lon 42.51/-92.82
End Date 08/11/2010 02:30:00 CST-6
End Range 6
End Azimuth WNW
End Location FERN
End Lat/Lon 42.51/-92.87
Deaths Direct/Indirect 0/0 (fatality details below, when available...)
Injuries Direct/Indirect 0/0
Property Damage 10.00K
Crop Damage 0.00K
Episode Narrative 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 1000 and 1800 J/kg. Available CAPE in the -10 to -30 C layer of the atmosphere was 800-1100 J/kg, but hail was limited by the high freezing level, 16,000 to 16,500 feet. Quarter size hail fell in Calhoun County as an intense storm passed though. The same storm cluster produced a funnel cloud in Sac County earlier. Scattered winds occurred with the storms. A 61 MPH wind gust was recorded in Eagle Grove for example and windows were blown out in Humboldt County south of Thor. One of the thunderstorms produced a tornado in Emmet County. The tornado touched down briefly over Lake Iowa. Thunderstorms became more organized during the evening and produced very heavy rainfall. In addition to the rainfall, scattered reports of high winds and some hail up to an inch and one quarter in size were received. Most of the wind reports were around 60 MPH. By far the most significant weather was the heavy rainfall. Three to 5 inches of rain fell on saturated ground, resulting in a very widespread flash flood event. Nearly half of the CWA was involved from parts of north central Iowa south to the Missouri border. Numerous roads were covered with flowing water of 1 to 2 feet in depth. Lightning struck a car at mile post 105 on Interstate 35 in Story County. No injuries were reported. Lightning also struck a house in Ankeny, causing a fire. The flash flooding claimed one life in central Iowa. Three vehicles were swept into the waters of Mud Creek near Altoona in Polk County. There were 11 people involved. A rescue call was made to save the occupants of the cars. One 16 year old female perished in the flood waters, the other 10 were rescued, though 4 were injured and received treatment at a local hospital. The flash flooding transitioned into widespread flooding as the night progressed into the day of the 11th. Flash flooding resulted in evacuations of apartments and trailer courts on the east side of Des Moines. Interstate 35 was covered by water due to flash flooding at mile post 97. Several cars spun out in the flood waters. Very intense rainfall in the Ames area resulted in a record crest on Squaw Creek. The creek crested 1.5 to 2.5 feet above the record high stage. Major flooding took place and the water treatment plant was inundated. Major damage was done to several buildings on the Iowa State Campus. Damage to Iowa State alone was between $40,000,000 and $50,000,000. Flooding from the Skunk River closed U.S. Highway 30. Thirty people were rescued at a Wal-Mart store in Ames as well. Following the severe flooding, several Iowa counties were added to the Presidential Disaster Declaration number 1930. The original 32 were: Adams, Appanoose, Audubon, Buena Vista, Butler, Cherokee, Clay, Davis, Decatur, Franklin, Howard, Humboldt, Iowa, Lee, Lyon, Madison, Marion, Mills, Monroe, Montgomery, O���Brien, Osceola, Palo Alto, Ringgold, Shelby, Union, Van Buren, Wapello, Warren, Wayne, Webster and Wright. Eighteen were added to the original, incuding: Black Hawk, Boone, Buchanan, Clayton, Delaware, Dickinson, Dubuque, Emmet, Fayette, Guthrie, Jackson, Jasper, Jones, Lucas, Mahaska, Polk, Sioux and Story. In addition, Governor Chet Culver had issued disaster proclamations for 50 Iowa counties due to inclement weather since June 1, 2010: Appanoose, Black Hawk, Boone, Buchanan, Buena Vista, Butler, Cherokee, Clay, Clayton, Davis, Decatur, Delaware, Dickinson, Dubuque, Emmet, Fayette, Franklin, Hamilton, Hancock, Howard, Humboldt, Jackson, Jasper, Jefferson, Johnson, Jones, Kossuth, Lee, Lucas, Lyon, Mahaska, Marion, Monona, Monroe, O'Brien, Osceola, Palo Alto, Polk, Ringgold, Shelby, Sioux, Story, Taylor, Union, Van Buren, Wapello, Warren, Washington, Webster and Wright.
Event Narrative Water of unknown depth running over 120th Street between I Ave and L Ave.


All events for this episode:

Location County/Zone St. Date Time T.Z. Type Mag Dth Inj PrD CrD
Totals: 1 4 52.352M 135.00K
SAC CITY SAC CO. IA 08/10/2010 14:57 CST-6 Funnel Cloud 0 0 0.00K 0.00K
BURNSIDE WEBSTER CO. IA 08/10/2010 16:00 CST-6 Heavy Rain 0 0 0.00K 0.00K
THOR HUMBOLDT CO. IA 08/10/2010 16:44 CST-6 Thunderstorm Wind 52 kts. EG 0 0 2.00K 0.00K
ARMSTRONG EMMET CO. IA 08/10/2010 16:44 CST-6 Tornado EF0 0 0 0.00K 0.00K
EAGLE GROVE WRIGHT CO. IA 08/10/2010 16:56 CST-6 Thunderstorm Wind 53 kts. MG 0 0 2.00K 0.00K
POMEROY CALHOUN CO. IA 08/10/2010 17:00 CST-6 Heavy Rain 0 0 0.00K 0.00K
LUNDGREN WEBSTER CO. IA 08/10/2010 17:00 CST-6 Heavy Rain 0 0 0.00K 0.00K
ROCKWELL CITY CALHOUN CO. IA 08/10/2010 17:15 CST-6 Hail 1.00 in. 0 0 2.00K 0.00K
CALLENDER WEBSTER CO. IA 08/10/2010 17:57 CST-6 Heavy Rain 0 0 0.00K 0.00K
RANDALL HAMILTON CO. IA 08/10/2010 18:00 CST-6 Heavy Rain 0 0 0.00K 0.00K
CLAY WORKS WEBSTER CO. IA 08/10/2010 18:50 CST-6 Flash Flood 0 0 250.00K 0.00K
CLAY WORKS WEBSTER CO. IA 08/10/2010 19:15 CST-6 Heavy Rain 0 0 0.00K 0.00K
YETTER CALHOUN CO. IA 08/10/2010 19:26 CST-6 Hail 1.25 in. 0 0 5.00K 10.00K
BURNSIDE WEBSTER CO. IA 08/10/2010 19:30 CST-6 Flash Flood 0 0 100.00K 0.00K
MOORLAND WEBSTER CO. IA 08/10/2010 19:30 CST-6 Flash Flood 0 0 50.00K 0.00K
STANHOPE HAMILTON CO. IA 08/10/2010 20:07 CST-6 Flash Flood 0 0 100.00K 0.00K
POLK CITY POLK CO. IA 08/10/2010 20:07 CST-6 Heavy Rain 0 0 0.00K 0.00K
MACKEY BOONE CO. IA 08/10/2010 20:13 CST-6 Heavy Rain 0 0 0.00K 0.00K
LUNDGREN WEBSTER CO. IA 08/10/2010 20:15 CST-6 Flash Flood 0 0 50.00K 0.00K
BURNSIDE WEBSTER CO. IA 08/10/2010 20:20 CST-6 Flash Flood 0 0 100.00K 0.00K
WAVERLY BREMER CO. IA 08/10/2010 20:23 CST-6 Flash Flood 0 0 50.00K 0.00K
POMEROY CALHOUN CO. IA 08/10/2010 20:30 CST-6 Heavy Rain 0 0 0.00K 0.00K
WATERLOO RANCH ARPT BLACK HAWK CO. IA 08/10/2010 20:45 CST-6 Thunderstorm Wind 50 kts. EG 0 0 15.00K 0.00K
KNIERIM CALHOUN CO. IA 08/10/2010 20:50 CST-6 Flash Flood 0 0 10.00K 0.00K
LYTTON CALHOUN CO. IA 08/10/2010 20:50 CST-6 Flash Flood 0 0 10.00K 0.00K
ONTARIO STORY CO. IA 08/10/2010 20:52 CST-6 Heavy Rain 0 0 0.00K 0.00K
MONTOUR TAMA CO. IA 08/10/2010 20:53 CST-6 Thunderstorm Wind 50 kts. EG 0 0 2.00K 0.00K
HOPE GREENE CO. IA 08/10/2010 20:54 CST-6 Flash Flood 0 0 25.00K 0.00K
MACKEY BOONE CO. IA 08/10/2010 20:57 CST-6 Flash Flood 0 0 10.00K 0.00K
ENTERPRISE POLK CO. IA 08/10/2010 21:00 CST-6 Heavy Rain 0 0 0.00K 0.00K
STORY CITY STORY CO. IA 08/10/2010 21:05 CST-6 Flash Flood 0 0 25.00K 0.00K
RANDALL HAMILTON CO. IA 08/10/2010 21:23 CST-6 Heavy Rain 0 0 0.00K 0.00K
STORY CITY STORY CO. IA 08/10/2010 21:29 CST-6 Flash Flood 0 0 500.00K 0.00K
JEWELL HAMILTON CO. IA 08/10/2010 21:30 CST-6 Flash Flood 0 0 25.00K 0.00K
STRATFORD HAMILTON CO. IA 08/10/2010 21:30 CST-6 Flash Flood 0 0 10.00K 0.00K
DAYTON WEBSTER CO. IA 08/10/2010 21:30 CST-6 Flash Flood 0 0 25.00K 0.00K
ZEARING STORY CO. IA 08/10/2010 21:48 CST-6 Flash Flood 0 0 25.00K 0.00K
ORALABOR POLK CO. IA 08/10/2010 22:00 CST-6 Thunderstorm Wind 52 kts. EG 0 0 2.00K 0.00K
ANKENY POLK CO. IA 08/10/2010 22:10 CST-6 Flash Flood 0 0 25.00K 0.00K
WEBSTER CITY ARPT HAMILTON CO. IA 08/10/2010 22:22 CST-6 Heavy Rain 0 0 0.00K 0.00K
CUMBERLAND CASS CO. IA 08/10/2010 22:29 CST-6 Thunderstorm Wind 52 kts. EG 0 0 0.00K 0.00K
CUMBERLAND CASS CO. IA 08/10/2010 22:40 CST-6 Thunderstorm Wind 52 kts. EG 0 0 3.00K 0.00K
ANKENY POLK CO. IA 08/10/2010 23:16 CST-6 Flash Flood 0 0 25.00K 0.00K
MIDVALE STORY CO. IA 08/10/2010 23:20 CST-6 Lightning 0 0 1.00K 0.00K
ANKENY POLK CO. IA 08/10/2010 23:20 CST-6 Flash Flood 0 0 25.00K 0.00K
ELKHART POLK CO. IA 08/10/2010 23:31 CST-6 Flash Flood 0 0 50.00K 25.00K
WOODWARD DALLAS CO. IA 08/10/2010 23:53 CST-6 Thunderstorm Wind 52 kts. EG 0 0 3.00K 0.00K
ANKENY POLK CO. IA 08/10/2010 23:54 CST-6 Flash Flood 0 0 25.00K 0.00K
FERN GRUNDY CO. IA 08/10/2010 23:55 CST-6 Flash Flood 0 0 25.00K 0.00K
FERN GRUNDY CO. IA 08/10/2010 23:55 CST-6 Flash Flood 0 0 10.00K 0.00K
ANKENY POLK CO. IA 08/11/2010 00:25 CST-6 Flash Flood 0 0 25.00K 0.00K
TRACY MARION CO. IA 08/11/2010 00:35 CST-6 Flash Flood 0 0 10.00K 0.00K
HARVEY MARION CO. IA 08/11/2010 00:35 CST-6 Flash Flood 0 0 50.00K 0.00K
STORY CITY STORY CO. IA 08/11/2010 00:37 CST-6 Heavy Rain 0 0 0.00K 0.00K
GEORGETOWN MONROE CO. IA 08/11/2010 03:26 CST-6 Flash Flood 0 0 10.00K 0.00K
SANTIAGO POLK CO. IA 08/11/2010 03:55 CST-6 Flash Flood 1 4 100.00K 25.00K
ANKENY POLK CO. IA 08/11/2010 04:00 CST-6 Lightning 0 0 20.00K 0.00K
SANTIAGO POLK CO. IA 08/11/2010 04:40 CST-6 Flash Flood 0 0 50.00K 25.00K
BURNSIDE WEBSTER CO. IA 08/11/2010 05:30 CST-6 Heavy Rain 0 0 0.00K 0.00K
DES MOINES POLK CO. IA 08/11/2010 06:30 CST-6 Flash Flood 0 0 100.00K 0.00K
ALTOONA POLK CO. IA 08/11/2010 08:17 CST-6 Heavy Rain 0 0 0.00K 0.00K
GOWRIE WEBSTER CO. IA 08/11/2010 09:00 CST-6 Flood 0 0 200.00K 0.00K
STANHOPE HAMILTON CO. IA 08/11/2010 11:02 CST-6 Flood 0 0 200.00K 50.00K
AMES STORY CO. IA 08/11/2010 11:07 CST-6 Flood 0 0 50.000M 0.00K
Totals: 1 4 52.352M 135.00K