A stalled boundary produced rounds of severe storms with very heavy rain, numerous reports of damaging winds of 60 to 75 mph, several large hail events, and a brief tornado. This event started in the afternoon and lasted into the evening hours and overnight.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:30:00 to 11-JUL-17 23:30:00 (CST-6)
Location: ASBURY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported several trees and branches were down.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:34:00 to 11-JUL-17 23:34:00 (CST-6)
Location: CENTER GROVE
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement reported multiple trees were down throughout the city of Dubuque from high winds.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:50:00 to 11-JUL-17 23:50:00 (CST-6)
Location: CENTER GROVE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported numerous trees were down in the city of Dubuque. Also, many roads were impassable due to a combination of trees down and flash flooding occurring.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:50:00 to 11-JUL-17 23:50:00 (CST-6)
Location: DURANGO
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported numerous trees were down.  Highway 52 was closed due to the number of trees down in multiple locations.

Flash Flood in DUBUQUE, IOWA
From 12-JUL-17 02:10:00 to 12-JUL-17 05:10:00 (CST-6)
Location: SAGEVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A public report was received via social media that Sageville Road, north of town was flooded.

Thunderstorm Wind in CEDAR, IOWA
From 12-JUL-17 18:47:00 to 12-JUL-17 18:47:00 (CST-6)
Location: STANWOOD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Iowa Department of Transportation reported a couple of trees were down in the town of Stanwood.

Flash Flood in DUBUQUE, IOWA
From 12-JUL-17 03:25:00 to 12-JUL-17 06:25:00 (CST-6)
Location: DURANGO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported water remained over Highway 52 near Durango, due to little Maquoketa Creek. The water was no longer rising but area was blocked to traffic.

Thunderstorm Wind in CLINTON, IOWA
From 12-JUL-17 19:29:00 to 12-JUL-17 19:29:00 (CST-6)
Location: DEWITT
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Clinton County Roads Department reported a few trees had to be cleared from secondary roads around the DeWitt area.

Thunderstorm Wind in CLINTON, IOWA
From 12-JUL-17 19:52:00 to 12-JUL-17 19:52:00 (CST-6)
Location: CLINTON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported a few trees down in the city of Clinton.

Thunderstorm Wind in DUBUQUE, IOWA
From 12-JUL-17 00:00:00 to 12-JUL-17 00:00:00 (CST-6)
Location: CENTER GROVE
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported a 10 inch in diameter ash tree was blown over along with several 2 to 4 inch in diameter tree limbs.

Thunderstorm Wind in CEDAR, IOWA
From 12-JUL-17 18:49:00 to 12-JUL-17 18:49:00 (CST-6)
Location: STANWOOD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported large tree branches were down north of town.

Hail in JOHNSON, IOWA
From 11-JUL-17 18:25:00 to 11-JUL-17 18:25:00 (CST-6)
Location: IOWA CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported pea to dime sized hail on the east side of Iowa City at 7th and Muscatine Avenue.

Hail in JOHNSON, IOWA
From 11-JUL-17 18:50:00 to 11-JUL-17 18:50:00 (CST-6)
Location: OASIS
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Report of 1.5 inch in diameter hail was received from the county emergency manager.

Hail in DUBUQUE, IOWA
From 11-JUL-17 21:48:00 to 11-JUL-17 21:48:00 (CST-6)
Location: HOLY CROSS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Report of hail up to the size of 1 inch in diameter was received from the county emergency manager.

Hail in DUBUQUE, IOWA
From 11-JUL-17 21:57:00 to 11-JUL-17 21:57:00 (CST-6)
Location: HOLY CROSS
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A report of hail up to the size of 1.25 inches in diameter was received from the county emergency manager.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:30:00 to 11-JUL-17 23:30:00 (CST-6)
Location: ASBURY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported tree branches up to 4 inches in diameter were down just west of Asbury.

Hail in DUBUQUE, IOWA
From 11-JUL-17 23:34:00 to 11-JUL-17 23:34:00 (CST-6)
Location: CENTER GROVE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement reported multiple occurrences of nickel to quarter sized hail  throughout the city.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:34:00 to 11-JUL-17 23:34:00 (CST-6)
Location: CENTER GROVE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement had received multiple reports of winds estimated at 50 to 60 mph.

Thunderstorm Wind in DUBUQUE, IOWA
From 11-JUL-17 23:41:00 to 11-JUL-17 23:41:00 (CST-6)
Location: (DBQ)DUBUQUE MUNI AR
Magnitude: 65.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

This wind gust of 75 mph was measured by the Dubuque ASOS site.

Thunderstorm Wind in CEDAR, IOWA
From 12-JUL-17 18:48:00 to 12-JUL-17 18:48:00 (CST-6)
Location: MECHANICSVILLE
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

This report from local law enforcement is the measured high gust from a local wind sensor.

Tornado in IOWA, IOWA
From 11-JUL-17 16:35:00 to 11-JUL-17 16:54:00 (CST-6)
Location: WILLIAMSBURG
Tornado F-scale: EF1
Property damage: 1.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado was rated an EF-1 with peak winds of 105 mph, a path length of 4.58 miles, with a max width of 60 yards. The tornado produced damage to mainly trees and crops with two houses also sustaining damage to windows.

Flash Flood in DUBUQUE, IOWA
From 12-JUL-17 00:14:00 to 12-JUL-17 03:14:00 (CST-6)
Location: DURANGO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement reported several roads impassable and closed due to high water in the city of Dubuque.