An intense storm system brought record warmth, high winds, and a serial derecho though Iowa and the Upper Midwest on December 15th.  This storm system produced a line of severe storms which continually produced damaging winds and tornadoes from Nebraska through much of Iowa. In eastern Iowa and Illinois, no tornadoes occurred, but widespread severe wind gusts occurred with brief heavy rain.
Strong winds occurred through the day along with the record high temperatures. After the storms moved through, those winds peaked at 60 to 80 mph for several hours in the late evening.

Thunderstorm Wind in JONES, IOWA
From 15-DEC-21 21:03:00 to 15-DEC-21 21:03:00 (CST-6)
Location: FAIRVIEW
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT automated observation.

Thunderstorm Wind in LEE, IOWA
From 15-DEC-21 21:06:00 to 15-DEC-21 21:06:00 (CST-6)
Location: KEOKUK ARPT
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Keokuk Airport observation.

Thunderstorm Wind in LEE, IOWA
From 15-DEC-21 21:10:00 to 15-DEC-21 21:10:00 (CST-6)
Location: KEOKUK
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported severe winds.

Thunderstorm Wind in CEDAR, IOWA
From 15-DEC-21 21:25:00 to 15-DEC-21 21:25:00 (CST-6)
Location: LOWDEN
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in MUSCATINE, IOWA
From 15-DEC-21 21:27:00 to 15-DEC-21 21:27:00 (CST-6)
Location: MUSCATINE
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in SCOTT, IOWA
From 15-DEC-21 21:37:00 to 15-DEC-21 21:37:00 (CST-6)
Location: MAYSVILLE
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT automated observation of severe winds.

Thunderstorm Wind in JACKSON, IOWA
From 15-DEC-21 21:40:00 to 15-DEC-21 21:40:00 (CST-6)
Location: MAQUOKETA
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT automated observation.

Thunderstorm Wind in SCOTT, IOWA
From 15-DEC-21 21:40:00 to 15-DEC-21 21:40:00 (CST-6)
Location: MAYSVILLE
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:13:00 to 15-DEC-21 20:13:00 (CST-6)
Location: CHENEY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A tree was reported blown down over Highway 150.

Thunderstorm Wind in BUCHANAN, IOWA
From 15-DEC-21 20:13:00 to 15-DEC-21 20:13:00 (CST-6)
Location: STANLEY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tree was reported blown down.

Thunderstorm Wind in VAN BUREN, IOWA
From 15-DEC-21 20:20:00 to 15-DEC-21 20:20:00 (CST-6)
Location: LAKE SUGEMA CAMP GD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several 3 to 4 inch diameter tree branched blown down.

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:30:00 to 15-DEC-21 20:30:00 (CST-6)
Location: WALFORD
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A semi-trailer was blown over during severe thunderstorm winds. The driver was thrown from the vehicle and pronounced dead at the scene.

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:32:00 to 15-DEC-21 20:32:00 (CST-6)
Location: TIFFIN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds threw a trampoline against a home, damaging the siding and driving a pole into the house.

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:42:00 to 15-DEC-21 20:42:00 (CST-6)
Location: OAKDALE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gust knocked down a metal shed.

Thunderstorm Wind in LINN, IOWA
From 15-DEC-21 20:45:00 to 15-DEC-21 20:45:00 (CST-6)
Location: COGGON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tree was blown down on a house.

Thunderstorm Wind in DELAWARE, IOWA
From 15-DEC-21 20:48:00 to 15-DEC-21 20:48:00 (CST-6)
Location: ROBINSON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Shingles damaged at home, with other damage in neighborhood.

Thunderstorm Wind in DELAWARE, IOWA
From 15-DEC-21 20:49:00 to 15-DEC-21 20:49:00 (CST-6)
Location: GREELEY
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

House and roofs damaged in Greeley and Oneida.

Thunderstorm Wind in LOUISA, IOWA
From 15-DEC-21 21:13:00 to 15-DEC-21 21:13:00 (CST-6)
Location: GRANDVIEW
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Part of a building was reported blown onto the roadway.

Thunderstorm Wind in DES MOINES, IOWA
From 15-DEC-21 21:19:00 to 15-DEC-21 21:19:00 (CST-6)
Location: DODGEVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tree was blown over onto power lines.

Thunderstorm Wind in VAN BUREN, IOWA
From 15-DEC-21 21:20:00 to 15-DEC-21 21:20:00 (CST-6)
Location: LAKE SUGEMA CAMP GD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several 3 to 4 inch diameter tree branches blown down.

Thunderstorm Wind in DES MOINES, IOWA
From 15-DEC-21 21:22:00 to 15-DEC-21 21:22:00 (CST-6)
Location: WEST BURLINGTON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A shed was blown down, and skirting blown off the edge of a mobile home.

Thunderstorm Wind in MUSCATINE, IOWA
From 15-DEC-21 21:24:00 to 15-DEC-21 21:24:00 (CST-6)
Location: MUSCATINE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Power poles reported broken.

Thunderstorm Wind in LOUISA, IOWA
From 15-DEC-21 21:30:00 to 15-DEC-21 21:30:00 (CST-6)
Location: COLUMBUS CITY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A tree was reported down on a roadway 3 miles west of Columbus Junction.

Thunderstorm Wind in JACKSON, IOWA
From 15-DEC-21 21:38:00 to 15-DEC-21 21:38:00 (CST-6)
Location: MAQUOKETA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Power poles were reported broken.

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:02:00 to 15-DEC-21 20:02:00 (CST-6)
Location: BLAIRSTOWN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Report relayed though emergency manager.

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:20:00 to 15-DEC-21 20:20:00 (CST-6)
Location: CHENEY
Magnitude: 66.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:24:00 to 15-DEC-21 20:24:00 (CST-6)
Location: NORWAY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Report relayed by emergency manager.

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:26:00 to 15-DEC-21 20:26:00 (CST-6)
Location: NORWAY
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Report relayed by emergency manager.

Thunderstorm Wind in LINN, IOWA
From 15-DEC-21 20:30:00 to 15-DEC-21 20:30:00 (CST-6)
Location: (CID)CEDAR RAPIDS AR
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Eastern Iowa Regional Airport / Cedar Rapids observation.

Thunderstorm Wind in BENTON, IOWA
From 15-DEC-21 20:32:00 to 15-DEC-21 20:32:00 (CST-6)
Location: ATKINS
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:52:00 to 15-DEC-21 20:52:00 (CST-6)
Location: WILLIAMSTOWN
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:52:00 to 15-DEC-21 20:52:00 (CST-6)
Location: IOWA CITY MUNI ARPT
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Iowa City Municipal Airport observation.

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:54:00 to 15-DEC-21 20:54:00 (CST-6)
Location: IOWA CITY MUNI ARPT
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in HENRY, IOWA
From 15-DEC-21 20:55:00 to 15-DEC-21 20:55:00 (CST-6)
Location: MT PLEASANT MUNI ARP
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Mt Pleasant Airport observation.

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 20:57:00 to 15-DEC-21 20:57:00 (CST-6)
Location: TIFFIN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported severe winds.

Thunderstorm Wind in JOHNSON, IOWA
From 15-DEC-21 21:00:00 to 15-DEC-21 21:00:00 (CST-6)
Location: IOWA CITY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Severe winds and the power is out.