A slow moving warm front over central Iowa allowed thunderstorms to develop over northern Iowa during the evening of the 22nd into the early morning of the 23rd. These storms then moved east across northeast Iowa into southwest Wisconsin producing damaging winds and heavy rain.  Storm surveys completed by staff members from the Des Moines National Weather Service estimated straight-line thunderstorm winds of 70 to 90 mph caused the damage.

Thunderstorm Wind in FAYETTE, IOWA
From 23-JUN-10 01:25:00 to 23-JUN-10 01:25:00 (CST-6)
Location: WESTGATE
Magnitude: 78.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Severe thunderstorm winds damaged several farm outbuildings, including a new grain bin. A NWS storm survey concluded the damage was created by straight-line winds of estimated speeds up to 90 mph.

Flood in CHICKASAW, IOWA
From 23-JUN-10 03:14:00 to 23-JUN-10 05:15:00 (CST-6)
Location: NEW HAMPTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rains produced some street flooding in New Hampton.  A 24-hour rainfall total of 2.30 inches was reported.

Flood in WINNESHIEK, IOWA
From 23-JUN-10 03:15:00 to 23-JUN-10 05:15:00 (CST-6)
Location: DECORAH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain produced some street flooding in the city of Decorah.

Flood in MITCHELL, IOWA
From 23-JUN-10 02:54:00 to 23-JUN-10 05:00:00 (CST-6)
Location: MONA
Flood cause: Heavy Rain
Property damage: 135.00K
Crop damage: 45.00K
Reported by: Law Enforcement

Heavy rainfall led to road damage and basement flooding.

Thunderstorm Wind in FAYETTE, IOWA
From 23-JUN-10 01:53:00 to 23-JUN-10 01:55:00 (CST-6)
Location: STANLEY
Magnitude: 78.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Severe thunderstorms winds created a path of damage between I and E Avenues just south of 20th Street. Several trees, power lines and buildings were damaged. A NWS storm survey determined the damage was created by straight-line winds of estimated speeds between 70 and 90 mph.

Thunderstorm Wind in CLAYTON, IOWA
From 23-JUN-10 02:14:00 to 23-JUN-10 02:14:00 (CST-6)
Location: MEDERVILLE
Magnitude: 56.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds knocked down trees along Evergreen Road.

Thunderstorm Wind in FAYETTE, IOWA
From 23-JUN-10 01:28:00 to 23-JUN-10 01:28:00 (CST-6)
Location: WESTGATE
Magnitude: 65.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Severe thunderstorms winds blew down a tree, broke some windows and created a propane leak.

Thunderstorm Wind in FAYETTE, IOWA
From 23-JUN-10 01:50:00 to 23-JUN-10 01:50:00 (CST-6)
Location: ARLINGTON
Magnitude: 75.00 EG
Property damage: 32.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Severe thunderstorm winds caused the roofs of two hog confinement buildings to cave in on a farm on County Road W45 (G Avenue). Media reports indicate several hogs had to later be destroyed due to the extent of their injuries suffered when the building collapsed. Several other farm buildings in the area were also damaged or blown down.

Flood in HOWARD, IOWA
From 23-JUN-10 03:00:00 to 23-JUN-10 05:30:00 (CST-6)
Location: CHESTER
Flood cause: Heavy Rain
Property damage: 150.00K
Crop damage: 50.00K
Reported by: Department of Highways

Rainfall of 2.5 to 4 inches during the evening of June 22 caused major damage to secondary roads across Howard County with 120 spots noting damage.