Two rounds of severe thunderstorms developed ahead of and along a cold front over northeast Iowa. The storms rolled across the area during the evening hours of September 4th into the early morning of the 5th. The severe thunderstorms produced hail up to two inches in diameter near Dorchester (Allamakee County) and blew down trees near Lansing (Allamakee County) and in Decorah (Winneshiek County).

Hail in CLAYTON, IOWA
From 04-SEP-12 22:05:00 to 04-SEP-12 22:05:00 (CST-6)
Location: OSBORNE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Up to ping pong ball sized hail fell in Osborne.

Hail in CLAYTON, IOWA
From 04-SEP-12 22:25:00 to 04-SEP-12 22:45:00 (CST-6)
Location: MEDERVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dime to quarter sized hail fell for around 20 minutes and covered the ground southwest of Mederville.

Thunderstorm Wind in FLOYD, IOWA
From 04-SEP-12 23:15:00 to 04-SEP-12 23:15:00 (CST-6)
Location: ROCKFORD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

An estimated wind gust of 60 miles per hour was reported in Rockford.

Thunderstorm Wind in WINNESHIEK, IOWA
From 05-SEP-12 00:24:00 to 05-SEP-12 00:24:00 (CST-6)
Location: DECORAH
Magnitude: 50.00 EG
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees were blown down in Decorah.

Heavy Rain in CLAYTON, IOWA
From 04-SEP-12 22:00:00 to 05-SEP-12 04:00:00 (CST-6)
Location: MEDERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

During the evening hours of the 4th into the early morning hours of the 5th, 3.52 inches of rail fell southwest of Elkader.

Hail in ALLAMAKEE, IOWA
From 04-SEP-12 17:31:00 to 04-SEP-12 17:31:00 (CST-6)
Location: CHESTER
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Up to 2 inch diameter hail fell in Dorchester.

Hail in ALLAMAKEE, IOWA
From 04-SEP-12 16:40:00 to 04-SEP-12 16:40:00 (CST-6)
Location: NEW ALBIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Golf ball sized hail fell in New Albin.

Hail in ALLAMAKEE, IOWA
From 04-SEP-12 18:04:00 to 04-SEP-12 18:04:00 (CST-6)
Location: CHESTER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in ALLAMAKEE, IOWA
From 04-SEP-12 18:25:00 to 04-SEP-12 18:25:00 (CST-6)
Location: HARPERS FERRY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Up to half dollar sized hail fell in Harpers Ferry.

Hail in FAYETTE, IOWA
From 04-SEP-12 20:48:00 to 04-SEP-12 20:48:00 (CST-6)
Location: CLERMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter sized hail fell in Clermont.

Hail in WINNESHIEK, IOWA
From 04-SEP-12 21:13:00 to 04-SEP-12 21:13:00 (CST-6)
Location: CALMAR
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Quarter sized hail fell in Calmar.

Hail in WINNESHIEK, IOWA
From 04-SEP-12 21:37:00 to 04-SEP-12 21:37:00 (CST-6)
Location: CALMAR
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail the size of walnuts fell in Calmar.

Hail in CLAYTON, IOWA
From 04-SEP-12 22:00:00 to 04-SEP-12 22:00:00 (CST-6)
Location: OSBORNE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Quarter sized hail was reported southwest of Elkader.

Hail in CLAYTON, IOWA
From 04-SEP-12 17:31:00 to 04-SEP-12 17:31:00 (CST-6)
Location: MARQUETTE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Golf ball sized hail fell in Marquette.

Thunderstorm Wind in ALLAMAKEE, IOWA
From 04-SEP-12 17:55:00 to 04-SEP-12 17:55:00 (CST-6)
Location: LANSING
Magnitude: 50.00 EG
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees were blown down on the north side of Lansing.

Hail in WINNESHIEK, IOWA
From 04-SEP-12 21:42:00 to 04-SEP-12 21:42:00 (CST-6)
Location: OSSIAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Quarter sized hail was reported southeast of Calmar.