Storm Events Database
- Data Access
- Search
- FTP Access
- Database Download
- Storm Data Publication
- Documentation
- Storm Data FAQ
- Storm Data Preparation
- Tornado EF Scale
- External Resources
- NOAA's SPC Reports
- NOAA's SPC WCM Page
- SHELDUS
Storm Events Database
Event Details
| Event | Thunderstorm Wind |
| Magnitude | 52 kts. |
| State | IOWA |
| County/Area | GRUNDY |
| WFO | DMX |
| Begin Date | 08/20/2007 22:53:00 CST-6 |
| Begin Range | 1 |
| Begin Azimuth | SW |
| Begin Location | GRUNDY CENTER |
| Begin Lat/Lon | 42.36/-92.78 |
| End Date | 08/20/2007 22:53:00 CST-6 |
| Deaths Direct/Indirect | 0/0 (fatality details below, when available...) |
| Injuries Direct/Indirect | 0/0 |
| Property Damage | 2.00K |
| Crop Damage | 0.00K |
| Episode Narrative | Little change took place in the overall weather pattern with a nearly stationary frontal boundary remaining over the state. The morning convection moved off allowing for afternoon solar isolation to take place, destabilizing the atmosphere once again. Temperatures over the southwest half of the state warmed into the mid to upper 80s with dew points in the low to mid 70s. West of Iowa it warmed into the mid 90s with mid 70 dew points. The airmass became very unstable with CAPE in the the 5000 to 8000 J/kg range from western Iowa west. Lifted indices fell into the -10 to -14 C. range by late afternoon. A considerable amount of shear remained in place with 40 to 55 kts present at the time of thunderstorm development. The LCL was reasonably high however at 1000 to 1500 meters. Thunderstorms developed in to a linear complex that showed a few bow echo elements along the leading edge. The main weather features with this system were high winds and hail. The available downdraft CAPE was between 1200 and 1500 J/kg and was favorable for high winds. There was 600 to 900 J/kg of available CAPE in the -10 to -30 C. layer of the atmosphere. In spite of the high values, hail size was limited by the high freezing levels, between 14,500 feet to over 15,500 feet. As the storms moved into the western part of the CWA, winds were the strongest. Reports of winds between 60 and 70 MPH were common along the leading edge of the line. The winds diminished as the storms moved east. Hail reports were spotty with this event. The hail was relatively small with most of it in the three quarter to one inch diameter range. The storms produced heavy rainfall once again with 1.6 to 1.8 inches of precipitable water available. The heavy rain fell in areas that were affected by the past several days of rain. Calhoun and Webster had some flash flooding, but it was relatively minor and limited to road closures caused by water flowing over the roads. |
| Event Narrative |
All events for this episode:
| Location | County/Zone | St. | Date | Time | T.Z. | Type | Mag | Dth | Inj | PrD | CrD |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Totals: | 0 | 0 | 208.00K | 95.00K | |||||||
| AUDUBON | AUDUBON CO. | IA | 08/20/2007 | 19:50 | CST-6 | Thunderstorm Wind | 61 kts. EG | 0 | 0 | 30.00K | 0.00K |
| AUDUBON | AUDUBON CO. | IA | 08/20/2007 | 19:52 | CST-6 | Hail | 1.00 in. | 0 | 0 | 5.00K | 50.00K |
| ATLANTIC | CASS CO. | IA | 08/20/2007 | 19:55 | CST-6 | Thunderstorm Wind | 57 kts. MG | 0 | 0 | 10.00K | 5.00K |
| IVEYVILLE | ADAMS CO. | IA | 08/20/2007 | 20:05 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 1.00K | 0.00K |
| CORNING | ADAMS CO. | IA | 08/20/2007 | 20:19 | CST-6 | Thunderstorm Wind | 50 kts. MG | 0 | 0 | 2.00K | 0.00K |
| PRESCOTT | ADAMS CO. | IA | 08/20/2007 | 20:23 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| GRAVITY | TAYLOR CO. | IA | 08/20/2007 | 20:28 | CST-6 | Thunderstorm Wind | 56 kts. EG | 0 | 0 | 10.00K | 5.00K |
| GRAVITY | TAYLOR CO. | IA | 08/20/2007 | 20:30 | CST-6 | Thunderstorm Wind | 56 kts. EG | 0 | 0 | 10.00K | 10.00K |
| NODAWAY | ADAMS CO. | IA | 08/20/2007 | 20:30 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 3.00K | 0.00K |
| CLEARFIELD | TAYLOR CO. | IA | 08/20/2007 | 20:31 | CST-6 | Thunderstorm Wind | 65 kts. EG | 0 | 0 | 75.00K | 10.00K |
| IVEYVILLE | ADAMS CO. | IA | 08/20/2007 | 20:31 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 3.00K | 0.00K |
| CRESTON | UNION CO. | IA | 08/20/2007 | 20:47 | CST-6 | Thunderstorm Wind | 53 kts. EG | 0 | 0 | 3.00K | 0.00K |
| MANSON | CALHOUN CO. | IA | 08/20/2007 | 21:02 | CST-6 | Hail | 1.00 in. | 0 | 0 | 10.00K | 0.00K |
| MT AYR | RINGGOLD CO. | IA | 08/20/2007 | 21:15 | CST-6 | Thunderstorm Wind | 57 kts. EG | 0 | 0 | 25.00K | 10.00K |
| DODGE FLD ARPT | POLK CO. | IA | 08/20/2007 | 21:19 | CST-6 | Hail | 1.00 in. | 0 | 0 | 2.00K | 0.00K |
| ANKENY | POLK CO. | IA | 08/20/2007 | 21:35 | CST-6 | Hail | 0.75 in. | 0 | 0 | 0.00K | 0.00K |
| TARA | WEBSTER CO. | IA | 08/20/2007 | 21:42 | CST-6 | Flash Flood | 0 | 0 | 5.00K | 0.00K | |
| EAGLE GROVE | WRIGHT CO. | IA | 08/20/2007 | 21:42 | CST-6 | Hail | 1.00 in. | 0 | 0 | 5.00K | 0.00K |
| RICHARDS | CALHOUN CO. | IA | 08/20/2007 | 21:48 | CST-6 | Flash Flood | 0 | 0 | 5.00K | 0.00K | |
| GRUNDY CENTER | GRUNDY CO. | IA | 08/20/2007 | 22:53 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| MARK | DAVIS CO. | IA | 08/20/2007 | 23:00 | CST-6 | Hail | 0.75 in. | 0 | 0 | 0.00K | 5.00K |
| Totals: | 0 | 0 | 208.00K | 95.00K |
