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Storm Events Database
Event Details
| Event | Thunderstorm Wind |
| Magnitude | 52 kts. |
| State | IOWA |
| County/Area | GRUNDY |
| WFO | DMX |
| Begin Date | 07/25/2012 20:38:00 CST-6 |
| Begin Range | 1 |
| Begin Azimuth | SE |
| Begin Location | CONRAD |
| Begin Lat/Lon | 42.22/-92.87 |
| End Date | 07/25/2012 20:38:00 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 | A very hot airmass was in place over Iowa, though it was capped through the daytime hours. High temperatures reached the mid to upper 90s in the north and 100 to 108 across the south. A cold front moved into northwest Iowa during the afternoon. Dewpoint temperatures pooled along the front to the 65 to 70 degree range. The atmosphere became unstable with the lifted index falling to around -5 C and CAPE increasing to between 2000 and 4000 J/kg. CAPE in the -10 to -30 C layer of the atmosphere was between 400 and 700 J/kg, but the freezing level was around 15,000 feet and shear 20 kts or less. Precipitable water values were high at around 2 inches. The primary mode of severe weather was high winds. A line of thunderstorms formed along the cold front during the early evening hours, rapid intensification once they broke through the cap. The storms became cold pool dominated by mid evening with the outflow boundary leading the storms by about 30 miles. Most of the storms produced winds of 50 to 60 MPH, with a few gusts of 65 to 75 MPH. The highest winds were in Carroll and Poweshiek Counties. Downdraft CAPE was between 1200 and 1800 J/kg. There was little tornado threat with the LCL between 2500 and 3500 meters. There were a few reports of hail, but most of the hail was under an inch in diameter and not a primary event. One report of golf ball size hail was received from the Ruthven area in Palo Alto County. Winds caused numerous power outages and also damaged many trees. As a storm moved through Boone County, the Central Iowa Expo building was flattened. It was under construction with three sides of the building completed. High winds at the Ames Airport flipped a plane over from the same storm that moved through Boone County. |
| Event Narrative | A large tree snapped in half by high winds. |
All events for this episode:
| Location | County/Zone | St. | Date | Time | T.Z. | Type | Mag | Dth | Inj | PrD | CrD |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Totals: | 0 | 0 | 490.00K | 305.00K | |||||||
| ESTHERVILLE | EMMET CO. | IA | 07/25/2012 | 17:17 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| RUTHVEN | PALO ALTO CO. | IA | 07/25/2012 | 17:23 | CST-6 | Hail | 1.75 in. | 0 | 0 | 10.00K | 10.00K |
| DEPEW | PALO ALTO CO. | IA | 07/25/2012 | 17:36 | CST-6 | Hail | 0.88 in. | 0 | 0 | 0.00K | 5.00K |
| ALGONA | KOSSUTH CO. | IA | 07/25/2012 | 18:05 | CST-6 | Thunderstorm Wind | 54 kts. MG | 0 | 0 | 0.00K | 0.00K |
| ALGONA MUNI ARPT | KOSSUTH CO. | IA | 07/25/2012 | 18:10 | CST-6 | Thunderstorm Wind | 54 kts. MG | 0 | 0 | 0.00K | 0.00K |
| WEST BEND | PALO ALTO CO. | IA | 07/25/2012 | 18:11 | CST-6 | Hail | 0.88 in. | 0 | 0 | 0.00K | 5.00K |
| ALGONA | KOSSUTH CO. | IA | 07/25/2012 | 18:20 | CST-6 | Hail | 1.00 in. | 0 | 0 | 2.00K | 5.00K |
| ALGONA | KOSSUTH CO. | IA | 07/25/2012 | 18:20 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 1.00K | 0.00K |
| CARROLL NEU ARPT | CARROLL CO. | IA | 07/25/2012 | 18:35 | CST-6 | Thunderstorm Wind | 53 kts. MG | 0 | 0 | 0.00K | 0.00K |
| BROCK RANCH ARPT | HUMBOLDT CO. | IA | 07/25/2012 | 18:35 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| GLIDDEN | CARROLL CO. | IA | 07/25/2012 | 18:37 | CST-6 | Thunderstorm Wind | 44 kts. EG | 0 | 0 | 2.00K | 0.00K |
| CARROLL | CARROLL CO. | IA | 07/25/2012 | 18:37 | CST-6 | Thunderstorm Wind | 61 kts. EG | 0 | 0 | 50.00K | 0.00K |
| BREDA | CARROLL CO. | IA | 07/25/2012 | 18:40 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| (FOD)FT DODGE MUNI A | WEBSTER CO. | IA | 07/25/2012 | 18:45 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 10.00K | 0.00K |
| CARROLL | CARROLL CO. | IA | 07/25/2012 | 18:48 | CST-6 | Thunderstorm Wind | 55 kts. MG | 0 | 0 | 2.00K | 0.00K |
| LOHRVILLE | CALHOUN CO. | IA | 07/25/2012 | 18:49 | CST-6 | Thunderstorm Wind | 61 kts. EG | 0 | 0 | 25.00K | 15.00K |
| ROCKWELL CITY | CALHOUN CO. | IA | 07/25/2012 | 18:53 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 5.00K | 0.00K |
| BRITT | HANCOCK CO. | IA | 07/25/2012 | 18:55 | CST-6 | Hail | 1.00 in. | 0 | 0 | 10.00K | 50.00K |
| CARROLL | CARROLL CO. | IA | 07/25/2012 | 18:55 | CST-6 | Thunderstorm Wind | 65 kts. EG | 0 | 0 | 25.00K | 50.00K |
| LANESBORO | CARROLL CO. | IA | 07/25/2012 | 18:55 | CST-6 | Thunderstorm Wind | 65 kts. EG | 0 | 0 | 10.00K | 50.00K |
| EAGLE GROVE | WRIGHT CO. | IA | 07/25/2012 | 18:55 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| BREDA | CARROLL CO. | IA | 07/25/2012 | 18:55 | CST-6 | Hail | 1.00 in. | 0 | 0 | 5.00K | 5.00K |
| ARCADIA | CARROLL CO. | IA | 07/25/2012 | 19:00 | CST-6 | Thunderstorm Wind | 61 kts. EG | 0 | 0 | 75.00K | 50.00K |
| JEFFERSON | GREENE CO. | IA | 07/25/2012 | 19:00 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 5.00K | 5.00K |
| BELMOND | WRIGHT CO. | IA | 07/25/2012 | 19:03 | CST-6 | Hail | 1.00 in. | 0 | 0 | 1.00K | 10.00K |
| BELMOND | WRIGHT CO. | IA | 07/25/2012 | 19:08 | CST-6 | Hail | 1.00 in. | 0 | 0 | 3.00K | 0.00K |
| FARNHAMVILLE | WEBSTER CO. | IA | 07/25/2012 | 19:10 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| GOWRIE | WEBSTER CO. | IA | 07/25/2012 | 19:10 | CST-6 | Thunderstorm Wind | 61 kts. EG | 0 | 0 | 25.00K | 5.00K |
| LIDDERDALE | CARROLL CO. | IA | 07/25/2012 | 19:10 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 5.00K | 0.00K |
| GOWRIE | WEBSTER CO. | IA | 07/25/2012 | 19:12 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 2.00K | 0.00K |
| BOXHOLM | BOONE CO. | IA | 07/25/2012 | 19:15 | CST-6 | Thunderstorm Wind | 56 kts. EG | 0 | 0 | 15.00K | 0.00K |
| BELMOND | WRIGHT CO. | IA | 07/25/2012 | 19:15 | CST-6 | Hail | 1.00 in. | 0 | 0 | 2.00K | 5.00K |
| EARLHAM | MADISON CO. | IA | 07/25/2012 | 19:27 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| THORNTON | CERRO GORDO CO. | IA | 07/25/2012 | 19:30 | CST-6 | Thunderstorm Wind | 57 kts. EG | 0 | 0 | 15.00K | 0.00K |
| BOXHOLM | BOONE CO. | IA | 07/25/2012 | 19:31 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 3.00K | 0.00K |
| OGDEN | BOONE CO. | IA | 07/25/2012 | 19:31 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 60.00K | 0.00K |
| HAVERHILL | MARSHALL CO. | IA | 07/25/2012 | 19:37 | CST-6 | Thunderstorm Wind | 56 kts. MG | 0 | 0 | 5.00K | 10.00K |
| POLK CITY | POLK CO. | IA | 07/25/2012 | 19:39 | CST-6 | Thunderstorm Wind | 52 kts. MG | 0 | 0 | 0.00K | 0.00K |
| CALLENDER | WEBSTER CO. | IA | 07/25/2012 | 19:40 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 3.00K | 0.00K |
| ALEXANDER | FRANKLIN CO. | IA | 07/25/2012 | 19:40 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 10.00K | 0.00K |
| BOONE MUNI ARPT | BOONE CO. | IA | 07/25/2012 | 19:40 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 2.00K | 0.00K |
| MAXWELL | STORY CO. | IA | 07/25/2012 | 19:40 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| MARSHALLTOWN | MARSHALL CO. | IA | 07/25/2012 | 19:43 | CST-6 | Thunderstorm Wind | 55 kts. MG | 0 | 0 | 0.00K | 0.00K |
| PLEASANT HILL | BOONE CO. | IA | 07/25/2012 | 19:46 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 1.00K | 0.00K |
| AMES ARPT | STORY CO. | IA | 07/25/2012 | 19:49 | CST-6 | Thunderstorm Wind | 59 kts. EG | 0 | 0 | 20.00K | 0.00K |
| AMES ARPT | STORY CO. | IA | 07/25/2012 | 19:50 | CST-6 | Thunderstorm Wind | 59 kts. MG | 0 | 0 | 10.00K | 5.00K |
| AMES | STORY CO. | IA | 07/25/2012 | 19:50 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 5.00K | 0.00K |
| STORY CITY | STORY CO. | IA | 07/25/2012 | 19:51 | CST-6 | Thunderstorm Wind | 50 kts. EG | 0 | 0 | 1.00K | 0.00K |
| NEVADA | STORY CO. | IA | 07/25/2012 | 19:53 | CST-6 | Thunderstorm Wind | 57 kts. EG | 0 | 0 | 10.00K | 0.00K |
| ROLAND | STORY CO. | IA | 07/25/2012 | 19:54 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 3.00K | 0.00K |
| STORY CITY | STORY CO. | IA | 07/25/2012 | 19:57 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 1.00K | 0.00K |
| COLO | STORY CO. | IA | 07/25/2012 | 20:03 | CST-6 | Thunderstorm Wind | 58 kts. MG | 0 | 0 | 5.00K | 0.00K |
| ROLAND | STORY CO. | IA | 07/25/2012 | 20:04 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 10.00K | 0.00K |
| HUXLEY | STORY CO. | IA | 07/25/2012 | 20:05 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 3.00K | 0.00K |
| STORY CITY | STORY CO. | IA | 07/25/2012 | 20:07 | CST-6 | Hail | 1.00 in. | 0 | 0 | 1.00K | 10.00K |
| COLFAX | JASPER CO. | IA | 07/25/2012 | 20:09 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 5.00K | 0.00K |
| JEWELL | HAMILTON CO. | IA | 07/25/2012 | 20:12 | CST-6 | Thunderstorm Wind | 61 kts. MG | 0 | 0 | 10.00K | 0.00K |
| SWANWOOD | POLK CO. | IA | 07/25/2012 | 20:14 | CST-6 | Hail | 0.75 in. | 0 | 0 | 0.00K | 5.00K |
| RED ROCK | MARION CO. | IA | 07/25/2012 | 20:30 | CST-6 | Thunderstorm Wind | 64 kts. MG | 0 | 0 | 0.00K | 0.00K |
| CONRAD | GRUNDY CO. | IA | 07/25/2012 | 20:38 | CST-6 | Thunderstorm Wind | 52 kts. EG | 0 | 0 | 2.00K | 0.00K |
| BROOKLYN | POWESHIEK CO. | IA | 07/25/2012 | 21:02 | CST-6 | Thunderstorm Wind | 57 kts. MG | 0 | 0 | 3.00K | 5.00K |
| Totals: | 0 | 0 | 490.00K | 305.00K |
