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 JO DAVIESS, ILLINOIS
From 09-JUL-20 15:40:00 to 09-JUL-20 15:40:00 (CST-6)
Location: MENOMINEE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A few trees down along Highway 20.

Thunderstorm Wind in MERCER, ILLINOIS
From 09-JUL-20 16:58:00 to 09-JUL-20 16:58:00 (CST-6)
Location: JOY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Social media report of flattened corn.

Thunderstorm Wind in MERCER, ILLINOIS
From 09-JUL-20 17:19:00 to 09-JUL-20 17:19:00 (CST-6)
Location: ALEDO
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Downed power pole reported.

Thunderstorm Wind in ROCK ISLAND, ILLINOIS
From 09-JUL-20 17:21:00 to 09-JUL-20 17:21:00 (CST-6)
Location: ANDALUSIA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree branch reported down in Andalusia on social media.

Thunderstorm Wind in WARREN, ILLINOIS
From 09-JUL-20 18:08:00 to 09-JUL-20 18:08:00 (CST-6)
Location: COLDBROOK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A corn field was flattened or damaged with 2 to 3 inch diameter branches down.

Thunderstorm Wind in MCDONOUGH, ILLINOIS
From 09-JUL-20 18:40:00 to 09-JUL-20 18:40:00 (CST-6)
Location: PRAIRIE CITY ARPT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reported several 2 to 3 inch diameter branches down.

Thunderstorm Wind in WARREN, ILLINOIS
From 09-JUL-20 17:23:00 to 09-JUL-20 17:23:00 (CST-6)
Location: LITTLE YORK
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A highway sign blown over and corn damaged. Report on social media.

Flash Flood in JO DAVIESS, ILLINOIS
From 09-JUL-20 16:30:00 to 09-JUL-20 18:30:00 (CST-6)
Location: EAST DUBUQUE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roughly 75% of Highway 20 under water, as seen in video from law enforcement.

Funnel Cloud in WARREN, ILLINOIS
From 09-JUL-20 17:34:00 to 09-JUL-20 17:34:00 (CST-6)
Location: KIRKWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Report of a funnel cloud relayed by emergency management.