Storms that developed in the early afternoon took advantage of the very high instability and had no trouble becoming strong, and even severe, in a short amount of time. Storms initially formed along and north of the Highway 30 corridor in eastern Iowa, produced widespread damage to crops in Buchanan and Delaware counties, and eventually went on to produce a wind gust near 60 mph at the Dubuque Regional Airport. Storms across this area eventually merged and slowed down, leading to localized rainfall amounts of 4-5 inches. This very heavy rainfall produced flash flooding in the Dubuque metro, with law enforcement reporting several road closures along Highway 20.
Storms continued to form along a line to the south through the mid afternoon, and reached the Mississippi River around 6-7 PM. Several reports of wind damage to trees were received from McDonough county to the Quad Cities metro area. A few reports of funnel clouds were also received from the Kirkwood, IL area, but no tornado was ever observed.

Thunderstorm Wind in JONES, IOWA
From 09-JUL-20 15:25:00 to 09-JUL-20 15:25:00 (CST-6)
Location: ANAMOSA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Social media shows a tree down and other large branches in Anamosa.

Thunderstorm Wind in MUSCATINE, IOWA
From 09-JUL-20 16:26:00 to 09-JUL-20 16:26:00 (CST-6)
Location: MUSCATINE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A peach tree branches of 4 to 6 inches in diameter broken, received from social media.

Thunderstorm Wind in MUSCATINE, IOWA
From 09-JUL-20 16:28:00 to 09-JUL-20 16:28:00 (CST-6)
Location: MUSCATINE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Neighbor's 60 foot tall ash tree split by thunderstorm wind.

Thunderstorm Wind in MUSCATINE, IOWA
From 09-JUL-20 16:40:00 to 09-JUL-20 16:40:00 (CST-6)
Location: WILTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several tree branches blown down in Wilton.

Flash Flood in DUBUQUE, IOWA
From 09-JUL-20 16:00:00 to 09-JUL-20 18:00:00 (CST-6)
Location: CENTER GROVE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

All intersections on Highway 20 from University Ave through downtown Dubuque are closed due to water over the roads.

Thunderstorm Wind in BUCHANAN, IOWA
From 09-JUL-20 12:40:00 to 09-JUL-20 12:40:00 (CST-6)
Location: AURORA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several 8 to 10 inch diameter tree branches snapped off trees.

Thunderstorm Wind in BENTON, IOWA
From 09-JUL-20 13:20:00 to 09-JUL-20 13:20:00 (CST-6)
Location: VAN HORNE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree branch at least 6 inches in diameter broken off.

Thunderstorm Wind in SCOTT, IOWA
From 09-JUL-20 17:30:00 to 09-JUL-20 17:30:00 (CST-6)
Location: BETTENDORF
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A three inch diameter tree branch blown down.

Thunderstorm Wind in SCOTT, IOWA
From 09-JUL-20 17:35:00 to 09-JUL-20 17:35:00 (CST-6)
Location: BETTENDORF
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was snapped off near the corner of Mississippi Blvd and 16th Street in Bettendorf.

Thunderstorm Wind in LINN, IOWA
From 09-JUL-20 14:20:00 to 09-JUL-20 14:20:00 (CST-6)
Location: (CID)CEDAR RAPIDS AR
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Recorded by rwis system.

Thunderstorm Wind in BUCHANAN, IOWA
From 09-JUL-20 13:43:00 to 09-JUL-20 13:43:00 (CST-6)
Location: QUASQUETON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tree and crop damage around Quasqueton due to straight line winds.

Thunderstorm Wind in BUCHANAN, IOWA
From 09-JUL-20 13:45:00 to 09-JUL-20 13:45:00 (CST-6)
Location: WINTHROP
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reports a large swath of corn blown down near Winthrop, due to straight line winds.

Thunderstorm Wind in DELAWARE, IOWA
From 09-JUL-20 14:21:00 to 09-JUL-20 14:21:00 (CST-6)
Location: GREELEY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Widespread corn flattened due to thunderstorm winds.

Thunderstorm Wind in DUBUQUE, IOWA
From 09-JUL-20 15:40:00 to 09-JUL-20 15:40:00 (CST-6)
Location: (DBQ)DUBUQUE MUNI AR
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Reported by the Dubuque Regional Airport.

Thunderstorm Wind in LINN, IOWA
From 09-JUL-20 14:49:00 to 09-JUL-20 14:49:00 (CST-6)
Location: CEDAR RAPIDS
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Video sent through social media showing a tree falling in a yard and over a road.

Thunderstorm Wind in DELAWARE, IOWA
From 09-JUL-20 14:50:00 to 09-JUL-20 14:50:00 (CST-6)
Location: HOPKINTON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Social media report of a 6 inch diameter tree snapped off by wind.