Thunderstorms caused damaging winds, heavy rain with flash flooding, and one report of marginally large hail in northwest Iowa from just before midnight on July 21st to a few hours after midnight on July 22nd.

Thunderstorm Wind in SIOUX, IOWA
From 21-JUL-10 23:38:00 to 21-JUL-10 23:38:00 (CST-6)
Location: ORANGE CITY
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Flash Flood in LYON, IOWA
From 21-JUL-10 23:40:00 to 22-JUL-10 03:00:00 (CST-6)
Location: ROCK RAPIDS MUNI ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain caused flash flooding of streets and basements.

Flash Flood in LYON, IOWA
From 21-JUL-10 23:40:00 to 22-JUL-10 03:00:00 (CST-6)
Location: INWOOD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain caused flash flooding of basements and roads.

Flash Flood in SIOUX, IOWA
From 22-JUL-10 00:00:00 to 22-JUL-10 04:00:00 (CST-6)
Location: CARMEL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Heavy rain caused flash flooding of streets, basements, local small streams, and yards.

Flash Flood in CHEROKEE, IOWA
From 22-JUL-10 00:30:00 to 22-JUL-10 05:30:00 (CST-6)
Location: CHEROKEE
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain caused flash flooding of numerous streets in the town of Cherokee. Basements and parkland were also flooded.

Hail in IDA, IOWA
From 22-JUL-10 00:30:00 to 22-JUL-10 00:30:00 (CST-6)
Location: GALVA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in BUENA VISTA, IOWA
From 22-JUL-10 00:39:00 to 22-JUL-10 00:39:00 (CST-6)
Location: LINN GROVE
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds blew down power lines and poles, causing power outages. The winds also caused tree damage, including several trees blown down.

Thunderstorm Wind in O'BRIEN, IOWA
From 22-JUL-10 00:40:00 to 22-JUL-10 00:40:00 (CST-6)
Location: HARTLEY
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds destroyed a machine shed.

Flash Flood in BUENA VISTA, IOWA
From 22-JUL-10 01:45:00 to 22-JUL-10 05:00:00 (CST-6)
Location: ALTA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy rain caused flash flooding of streets, local small creeks, and basements. A few homes and businesses were flooded. Some exhibits at the county fairgrounds were damaged when a building there was flooded.

Flash Flood in O'BRIEN, IOWA
From 22-JUL-10 00:30:00 to 22-JUL-10 05:00:00 (CST-6)
Location: SHELDON
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rain caused flash flooding of numerous streets, basements, and small streams, and a golf course. Several homes and businesses were flooded.

Flash Flood in LYON, IOWA
From 21-JUL-10 23:42:00 to 22-JUL-10 03:00:00 (CST-6)
Location: EDNA
Flood cause: Heavy Rain
Property damage: 80.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain caused flash flooding of roads in and near the town of George, with several roads and bridges washed out. Many other low areas were flooded, including several feet of water covering much of the local baseball park. A large storage garage was washed away, with a boat and some machinery destroyed or damaged. The flooding also affected many basements.

Thunderstorm Wind in SIOUX, IOWA
From 21-JUL-10 23:30:00 to 21-JUL-10 23:30:00 (CST-6)
Location: MAURICE
Magnitude: 87.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds destroyed one home and damaged at least 20 others. Homes that were damaged had broken windows, had parts of roofs and siding that were blown away, or had roofs damaged by falling trees. tree damage was widespread, and there were also downed power lines and power outages. One person was injured by broken glass, and three others were injured by flying debris, with one of the injured hospitalized.
The winds destroyed a large hog confinement structure.

Thunderstorm Wind in CHEROKEE, IOWA
From 22-JUL-10 00:20:00 to 22-JUL-10 00:20:00 (CST-6)
Location: CHEROKEE
Magnitude: 70.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds caused widespread tree damage, including several large trees blown down. Several homes and businesses were damaged by falling trees, and other had shingle and other roof damage. Several vehicles were also damaged by falling trees and tree debris. A storage shed full of sports equipment at the high school was destroyed, with the equipment damaged. Signs and power lines were blown down, and a power outage resulted. A semi was blown over near town.

Flash Flood in OSCEOLA, IOWA
From 22-JUL-10 00:15:00 to 22-JUL-10 03:00:00 (CST-6)
Location: SIBLEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain caused flash flooding of numerous roads and basements.