A line of strong to severe thunderstorms developed ahead of a cold front that pushed eastward across Iowa during the late afternoon and early evening hours. These storms brought damaging winds, torrential rain, and frequent lightning to the area.  Several downed trees, power outages, and 40 to 60 mph winds were reported.  Widespread rainfall amounts between 0.75 to 1.5 inches of rain fell in a short amount of time.  This produced flash flooding in the city of Clinton in Clinton County.

Thunderstorm Wind in JACKSON, IOWA
From 04-AUG-16 19:50:00 to 04-AUG-16 19:50:00 (CST-6)
Location: MAQUOKETA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported an estimated wind gust around 60 MPH.

Thunderstorm Wind in LINN, IOWA
From 04-AUG-16 19:05:00 to 04-AUG-16 19:05:00 (CST-6)
Location: CEDAR RAPIDS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter estimated a peak wind of 60 MPH.

Thunderstorm Wind in DELAWARE, IOWA
From 04-AUG-16 18:19:00 to 04-AUG-16 18:19:00 (CST-6)
Location: COLESBURG
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

The Fire Department reported that a 1 foot diameter branch from a 40 year old maple tree was broken off.

Thunderstorm Wind in LINN, IOWA
From 04-AUG-16 18:42:00 to 04-AUG-16 18:42:00 (CST-6)
Location: WALKER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported that a large tree limb was down that was larger than 2 inches in diameter.

Thunderstorm Wind in CEDAR, IOWA
From 04-AUG-16 19:30:00 to 04-AUG-16 19:30:00 (CST-6)
Location: STANWOOD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter estimated a peak wind gust around 65 MPH.

Thunderstorm Wind in DUBUQUE, IOWA
From 04-AUG-16 18:48:00 to 04-AUG-16 18:48:00 (CST-6)
Location: CENTER GROVE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

A state official reported numerous tree limbs down where Highway 52 comes into Dubuque. Some of the limbs were down homes.

Flash Flood in CLINTON, IOWA
From 04-AUG-16 21:58:00 to 04-AUG-16 23:58:00 (CST-6)
Location: CLINTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Emergency Manager for Clinton County reported street flooding in the city of Clinton with 1 to 2 feet of water over several intersections. Radar estimated rainfall showed over an inch of rain fell in one hour.

Thunderstorm Wind in DELAWARE, IOWA
From 04-AUG-16 18:18:00 to 04-AUG-16 18:18:00 (CST-6)
Location: COLESBURG
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

The Fire Department reported that a steel roof was blown off of a building across the the street from the Fire Station.

Thunderstorm Wind in CEDAR, IOWA
From 04-AUG-16 19:33:00 to 04-AUG-16 19:33:00 (CST-6)
Location: TIPTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement has received several reports of limbs and trees down in Tipton.  One of these limbs fell on powerlines and brought them down.

Thunderstorm Wind in SCOTT, IOWA
From 04-AUG-16 20:15:00 to 04-AUG-16 20:15:00 (CST-6)
Location: DAVENPORT
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public reported several trees down in Davenport. the report was received via Facebook.

Thunderstorm Wind in SCOTT, IOWA
From 04-AUG-16 20:15:00 to 04-AUG-16 20:15:00 (CST-6)
Location: SCOTT COUNTY PARK
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

An off duty NWS Employee reported several trees were down.  They also reported that there was significant damage to a strip mall.

Thunderstorm Wind in CLINTON, IOWA
From 04-AUG-16 20:30:00 to 04-AUG-16 20:30:00 (CST-6)
Location: DEWITT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

An off duty NWS Employee reported an approximately 8 inch diameter tree that was 25 feet tall was pulled out of the ground near their residence. They estimated winds of 45 to 50 MPH.