Severe thunderstorms developed rapidly during the late morning and afternoon along and behind a slow moving cold front. These thunderstorms initially developed over Minnesota and then moved southeast into northeast Iowa where they produced large hail and some wind damage. The largest hail reported was 1.75 inches in Ridgeway (Winneshiek County) before the storms became wind dominated. Trees were blown down or uprooted from Hesper (Winneshiek County) east through Waukon (Allamakee County) including a 65 mph gust near Calmar (Winneshiek County). 7 calves were killed when an almost 100 year old barn was blown down near Dorchester (Allamakee County).

Thunderstorm Wind in WINNESHIEK, IOWA
From 18-JUL-12 14:45:00 to 18-JUL-12 14:45:00 (CST-6)
Location: HESPER
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees were blown down in Hesper.

Thunderstorm Wind in WINNESHIEK, IOWA
From 18-JUL-12 14:49:00 to 18-JUL-12 14:49:00 (CST-6)
Location: SATTRE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Several trees were uprooted and corn in the area was bent over from the winds south of Highlandville.

Thunderstorm Wind in WINNESHIEK, IOWA
From 18-JUL-12 14:50:00 to 18-JUL-12 14:50:00 (CST-6)
Location: DECORAH
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Public

A large tree was uprooted just north of Decorah.

Hail in WINNESHIEK, IOWA
From 18-JUL-12 14:28:00 to 18-JUL-12 14:28:00 (CST-6)
Location: RIDGEWAY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Golf ball sized hail fell in Ridgeway.

Thunderstorm Wind in WINNESHIEK, IOWA
From 18-JUL-12 15:01:00 to 18-JUL-12 15:01:00 (CST-6)
Location: CONOVER
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A wind gust of 65 mph occurred north of Calmar.

Thunderstorm Wind in FAYETTE, IOWA
From 18-JUL-12 15:15:00 to 18-JUL-12 15:15:00 (CST-6)
Location: WEST UNION
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Some trees and power lines were blown down in West Union.

Heavy Rain in WINNESHIEK, IOWA
From 18-JUL-12 14:20:00 to 18-JUL-12 15:20:00 (CST-6)
Location: DECORAH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

In an hour, 1.5 inches of rain fell in Decorah.

Heavy Rain in CLAYTON, IOWA
From 18-JUL-12 15:20:00 to 18-JUL-12 15:50:00 (CST-6)
Location: MONONA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

In a half hour, 1.75 inches of rain fell in Monona.

Heavy Rain in WINNESHIEK, IOWA
From 18-JUL-12 14:50:00 to 18-JUL-12 15:50:00 (CST-6)
Location: BURR OAK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

In an hour, 1.75 inches of rain fell in Burr Oak.

Thunderstorm Wind in WINNESHIEK, IOWA
From 18-JUL-12 14:49:00 to 18-JUL-12 14:49:00 (CST-6)
Location: DECORAH
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A machine shed was blown down and across Twin Springs Road just southwest of Decorah.

Flood in HOWARD, IOWA
From 18-JUL-12 13:35:00 to 18-JUL-12 16:00:00 (CST-6)
Location: CRESCO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Numerous streets were flooded in Cresco and the water was deep enough in the downtown area to go over the curbs and threatened to go into some businesses. The flooding was produced by 2.65 inches of rain that fell in an hour and a half.

Thunderstorm Wind in ALLAMAKEE, IOWA
From 18-JUL-12 15:06:00 to 18-JUL-12 15:06:00 (CST-6)
Location: CHESTER
Magnitude: 50.00 EG
Property damage: 21.00K
Crop damage: 0.00K
Reported by: COOP Observer

A barn was destroyed by winds near Dorchester killing 7 calves that were inside the barn.

Hail in CHICKASAW, IOWA
From 18-JUL-12 14:24:00 to 18-JUL-12 14:24:00 (CST-6)
Location: FREDRICKSBURG
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public