Storm Events Database

Event Details

Event Thunderstorm Wind
Magnitude 61 kts.
State IOWA
County/Area PALO ALTO
WFO DMX
Begin Date 08/23/2011 01:14:00 CST-6
Begin Range 1
Begin Azimuth SE
Begin Location EMMETSBURG
Begin Lat/Lon 43.11/-94.68
End Date 08/23/2011 01:14:00 CST-6
Deaths Direct/Indirect 0/0 (fatality details below, when available...)
Injuries Direct/Indirect 0/0
Property Damage 50.00K
Crop Damage 10.00K
Episode Narrative Strong warm air advection took place over Iowa during the night of the 22nd into the morning of the 23rd. A low level jet of over 40 kts developed, transporting moisture into the state. Precipitable water values increased to between 1.7 and 2 inches over northwest into central Iowa. CAPE was in the 2000 to 4000 J/kg range to the southwest of the precipitable water maximum, with lifted indices of -6 to -10. Thunderstorms formed over South Dakota and moved into northwest and north central Iowa. The storms produced both hail and high winds as they advanced into the state. Downdraft CAPE was quite high with 1200 to 1400 J/kg available. CAPE in the -10 to -30 C layer of the atmosphere was between 500 and 1000 J/kg, however a very high freezing level limited the size of the hail as the freezing level was around 15,000 feet. The atmosphere was moderately sheared with 35 to 45 kts of shear available. By far the predominant mode of severe weather was the high winds. Trees were uprooted in Palo Alto County at Emmetsburg. Several other reports of winds of 60 to 70 MPH were received in Palo Alto and Kossuth County. A mesonet station northeast of Whittemore recorded a 75 MPH wind gust, with 68 MPH winds recorded at the Algona Airport for example. In Webster County, one inch diameter hail fell north of the Fort Dodge Airport. As the thunderstorms progressed eastward, the intensity diminished. There were spotty reports of high winds and hail across north central and parts of northeast Iowa. Scattered thunderstorms developed behind the main area before sunrise. For the most part they were not severe, but did produce high winds and some nickel to quarter size hail.
Event Narrative Numerous trees uprooted in town. Some minor flooding was also noted.


All events for this episode:

Location County/Zone St. Date Time T.Z. Type Mag Dth Inj PrD CrD
Totals: 0 0 231.00K 275.00K
EMMETSBURG PALO ALTO CO. IA 08/23/2011 01:14 CST-6 Thunderstorm Wind 61 kts. EG 0 0 50.00K 10.00K
EMMETSBURG PALO ALTO CO. IA 08/23/2011 01:14 CST-6 Thunderstorm Wind 52 kts. EG 0 0 10.00K 0.00K
WHITTEMORE KOSSUTH CO. IA 08/23/2011 01:35 CST-6 Thunderstorm Wind 65 kts. MG 0 0 25.00K 50.00K
ALGONA KOSSUTH CO. IA 08/23/2011 01:37 CST-6 Thunderstorm Wind 52 kts. EG 0 0 10.00K 0.00K
ALGONA MUNI ARPT KOSSUTH CO. IA 08/23/2011 01:40 CST-6 Thunderstorm Wind 59 kts. MG 0 0 10.00K 5.00K
ALGONA KOSSUTH CO. IA 08/23/2011 01:40 CST-6 Thunderstorm Wind 61 kts. EG 0 0 50.00K 0.00K
BRITT HANCOCK CO. IA 08/23/2011 02:00 CST-6 Thunderstorm Wind 52 kts. EG 0 0 5.00K 0.00K
(FOD)FT DODGE MUNI A WEBSTER CO. IA 08/23/2011 02:20 CST-6 Hail 1.00 in. 0 0 3.00K 25.00K
WEBSTER CITY HAMILTON CO. IA 08/23/2011 02:36 CST-6 Thunderstorm Wind 61 kts. EG 0 0 50.00K 0.00K
WEBSTER CITY ARPT HAMILTON CO. IA 08/23/2011 04:52 CST-6 Hail 1.00 in. 0 0 2.00K 10.00K
KAMRAR HAMILTON CO. IA 08/23/2011 04:57 CST-6 Hail 1.00 in. 0 0 1.00K 20.00K
KAMRAR HAMILTON CO. IA 08/23/2011 05:06 CST-6 Hail 0.88 in. 0 0 0.00K 5.00K
JOICE WORTH CO. IA 08/23/2011 05:52 CST-6 Thunderstorm Wind 52 kts. EG 0 0 5.00K 0.00K
NORTHWOOD MUNI ARPT WORTH CO. IA 08/23/2011 05:58 CST-6 Thunderstorm Wind 65 kts. EG 0 0 10.00K 150.00K
Totals: 0 0 231.00K 275.00K