December 15, 2021 was an unprecedented and historic event for the state of Iowa and the central US.  It featured the first-ever December derecho observed anywhere in the United States and the first Moderate Risk of severe thunderstorms issued by the NWS Storm Prediction Center in December for Iowa. Unofficially, it set the new single-day Iowa records for the most tornadoes and the most EF-2/F-2 or stronger tornadoes since 1950.  Finally, it will break the all-time December record high temperature for Iowa.
Tornadoes: There were 63 confirmed tornadoes that occurred in Iowa, 21 of which were rated EF-2. Sixty three is unofficially the most tornadoes in Iowa in a single day with the previous being 35 tornadoes on August 31, 2014. Further, 21 EF-2 tornadoes is unofficially the most EF-2/F-2 or stronger tornadoes in a single day with the previous being 16 tornadoes on June 7, 1984. Prior to this event, a total of 5 tornadoes had occurred in Iowa in December since 1950 with all of them in southeastern Iowa.

Thunderstorm Wind: Numerous straight line wind gusts were also associated with these thunderstorms, some in excess of 80 mph.  During the event, nearly the entire state of Iowa was under a Severe Thunderstorm Warning at some point.  Audubon reported the highest gust in Iowa at 88 mph. This storm also met the criteria for a ���derecho'', which makes it the first derecho on record in the month of December anywhere in the United States.  Finally, we had an unofficial gust of 108 mph recorded by a mesonet station near Sheffield, Iowa associated with one of the tornadic circulations.
Environmental Wind: After the line of storms had passed, numerous strong, non-thunderstorm wind gusts over 70 mph occurred overnight. The top three non-thunderstorm wind gusts were 83 mph in Decatur City, 81 mph in Marshalltown, and 80 mph in Johnston. The Des Moines International Airport recorded a 74 mph non-thunderstorm wind gust, which is the highest non-thunderstorm wind gust at this location since 1970.

Temperatures: In addition to the severe weather and strong non-thunderstorm winds, the temperatures were remarkable and record setting. Numerous record daily highs were broken by many degrees. In addition and preliminarily, the all-time December record high temperature for Iowa of 74 degrees that was set in Thurman, IA on December 6, 1939 was broken with four sites reaching 75 degrees (Oskaloosa, Muscatine, Iowa City, and Ottumwa).
For detailed environmental analysis, including soundings, please view the various local NWS office event review pages: NWS Des Moines, NWS Sioux Falls, NWS Omaha, NWS Wichita, NWS Pueblo, NWS Twin Cities, NWS Quad Cities, NWS Hastings, NWS La Crosse, NWS Green Bay, or NWS Milwaukee.

Tornado in FRANKLIN, IOWA
From 15-DEC-21 18:32:00 to 15-DEC-21 18:43:00 (CST-6)
Location: BRADFORD
Tornado F-scale: EF1
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado continued into Franklin County from Hardin County.  This path was determined using high resolution satellite imagery.  There was damage to trees and some outbuildings as the tornado moved northeast.   The tornado lifted just south of Highway 3 near the Handorf Roadside Park.

Tornado in WRIGHT, IOWA
From 15-DEC-21 18:28:00 to 15-DEC-21 18:29:00 (CST-6)
Location: OLAF
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado produced a depression on the WSR-88D correlation coefficient product and a short path was also observed on high resolution satellite imagery.  This tornado touched down in far north central Wright County and crossed over the Union Pacific rail line before entering into Hancock County.  No damage was reported in Wright County, hence the EFU rating for this segment.

Tornado in FRANKLIN, IOWA
From 15-DEC-21 18:38:00 to 15-DEC-21 18:43:00 (CST-6)
Location: CHAPIN
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado produced EF1 damage on the east side of Sheffield nearly destroying a business outbuilding.  The track farther to the southwest was found in high resolution satellite imagery and also confirmed through a private weather station which recorded a wind gust to 108 mph as the tornado passed its location.

Tornado in FRANKLIN, IOWA
From 15-DEC-21 18:40:00 to 15-DEC-21 18:46:00 (CST-6)
Location: GENEVA
Tornado F-scale: EF2
Property damage: 250.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado began a few miles north of Geneva and moved northeast producing plenty of tree damage as well as extensive outbuilding damage on two farmsteads.  Additional damage to a home with missing roofing and siding occurred along 170th Street west of Yarrow Avenue.  The tornado continue producing tree and power pole damage to the northeast before lifting on the north side of 190th Street near the West Fork Wildlife Area.

Tornado in CERRO GORDO, IOWA
From 15-DEC-21 18:44:00 to 15-DEC-21 18:46:00 (CST-6)
Location: ROCKWELL
Tornado F-scale: EF0
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was originally found using high resolution satellite imagery.  Some damage to trees did occur with little else noted.

Tornado in CERRO GORDO, IOWA
From 15-DEC-21 18:54:00 to 15-DEC-21 18:57:00 (CST-6)
Location: ROCK FALLS
Tornado F-scale: EF0
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Other Federal Agency

Another tornado found via high resolution satellite imagery.  The tornado did some minor tree damage with little additional damage as the tornado passed through far northeast rural Cerro Gordo County.

Tornado in WORTH, IOWA
From 15-DEC-21 18:58:00 to 15-DEC-21 19:05:00 (CST-6)
Location: KENSETT
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado developed to the west southwest of Kensett and raced northeast passing on east of Northwood near the Northwood Municipal Airport.  There was a few outbuildings damaged along the path with only EF0 rating.  The tornado dissipated about 2 miles northeast of Northwood.

Tornado in JASPER, IOWA
From 15-DEC-21 19:01:00 to 15-DEC-21 19:06:00 (CST-6)
Location: NEWTON MUNI ARPT
Tornado F-scale: EF0
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado developed nearly 5 miles south of Newton and raced northeast.  The tornado produced damage to several trees and a few outbuildings along the way.  The tornado passed over the south end of the Newton Airport runway and then proceeded across the Iowa Speedway with minor damage to several structures onsite.  The tornado proceeded to the northeast across Interstate 80 and eventually US Highway 6 east of Newton, dissipating shortly after passing over Highway 6.

Tornado in WINNEBAGO, IOWA
From 15-DEC-21 18:48:00 to 15-DEC-21 18:50:00 (CST-6)
Location: VINJE
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado touched down on the east edge of the Harmon Lake State Game Management Area and raced northward.  A couple of farmsteads were impacted producing EF1 damage.  This tornado crossed into Faribault County in Minnesota before dissipating.

Tornado in BUTLER, IOWA
From 15-DEC-21 18:53:00 to 15-DEC-21 18:54:00 (CST-6)
Location: GREENE
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was initially found using high resolution satellite imagery.  The tornado developed to the southwest of the intersection of county highway C13 and T24.  This tornado raced northeast and produce some minor damage before exiting into Floyd county east of county road T24 along Floyd Line Street.

Tornado in WORTH, IOWA
From 15-DEC-21 19:09:00 to 15-DEC-21 19:10:00 (CST-6)
Location: MELTONVILLE
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado developed near 500th Street east of county road S62 and raced through rural cropland.  The tornado produced no damage, hence the EFU rating in this county.  This tornado continued into Minnesota in Freeborn County.

High Wind in EMMET, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in PALO ALTO, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in KOSSUTH, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in WINNEBAGO, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in HANCOCK, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in WORTH, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 68.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in CERRO GORDO, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 65.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in FRANKLIN, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in BUTLER, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in BREMER, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in BLACK HAWK, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in GRUNDY, IOWA
From 15-DEC-21 20:00:00 to 16-DEC-21 02:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in POCAHONTAS, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in HUMBOLDT, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in SAC, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in CALHOUN, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in WEBSTER, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in WRIGHT, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in HAMILTON, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in GREENE, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in TAMA, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in POWESHIEK, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in JASPER, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in MAHASKA, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in BOONE, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in STORY, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in MARSHALL, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 70.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in POLK, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 64.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in HARDIN, IOWA
From 15-DEC-21 19:00:00 to 16-DEC-21 00:00:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in CRAWFORD, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in AUDUBON, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in GUTHRIE, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in CASS, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in MADISON, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in WARREN, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in MARION, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in ADAMS, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in UNION, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in RINGGOLD, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in MONROE, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in WAYNE, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in APPANOOSE, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in DAVIS, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in CARROLL, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in DALLAS, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in ADAIR, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in CLARKE, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in LUCAS, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in TAYLOR, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

High Wind in DECATUR, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 72.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in WAPELLO, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 23:00:00 (CST-6)
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Hail in CARROLL, IOWA
From 15-DEC-21 17:23:00 to 15-DEC-21 17:23:00 (CST-6)
Location: COON RAPIDS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in FRANKLIN, IOWA
From 15-DEC-21 18:32:00 to 15-DEC-21 18:32:00 (CST-6)
Location: LATIMER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter sized hail reported at the highway 3 and interstate 35 interchange.

Thunderstorm Wind in GUTHRIE, IOWA
From 15-DEC-21 17:32:00 to 15-DEC-21 17:32:00 (CST-6)
Location: HERNDON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of an outbuilding destroyed.

Thunderstorm Wind in CARROLL, IOWA
From 15-DEC-21 17:35:00 to 15-DEC-21 17:35:00 (CST-6)
Location: CARROLL NEU ARPT
Magnitude: 56.00 EG
Crop damage: 0.00K
Reported by: Law Enforcement

Outbuilding destroyed at the 240th St. and Timber Ave. intersection. Building size unknown.

Thunderstorm Wind in CRAWFORD, IOWA
From 15-DEC-21 16:55:00 to 15-DEC-21 16:55:00 (CST-6)
Location: DENISON MUNI ARPT
Magnitude: 70.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in ADAIR, IOWA
From 15-DEC-21 17:15:00 to 15-DEC-21 17:15:00 (CST-6)
Location: ADAIR
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reports 80 plus mph winds and zero visibility south of Adair.

Thunderstorm Wind in GUTHRIE, IOWA
From 15-DEC-21 17:17:00 to 15-DEC-21 17:17:00 (CST-6)
Location: NORTH BRANCH
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reports half inch hail and estimated 65 mph wind at highway 44 and Frontier road.

Thunderstorm Wind in GUTHRIE, IOWA
From 15-DEC-21 17:25:00 to 15-DEC-21 17:25:00 (CST-6)
Location: FANSLERS
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in GUTHRIE, IOWA
From 15-DEC-21 17:21:00 to 15-DEC-21 17:27:00 (CST-6)
Location: FANSLERS
Tornado F-scale: EF1
Property damage: 120.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado touched down north of Guthrie Center and promptly destroyed an outbuilding along State Highway 25.  The tornado continued northeast through wooded areas west of Springbrook State Park with some tree and minor house damage.   The tornado then emerged into more open cropland producing damage to a hog confinement and snapping large utility poles along 120th Street west of Quail Road.  The circulation passed west of Bagley and tipped over a semi on State Highway 141 and continued northeast before moving out of the county into Greene County.

Thunderstorm Wind in GREENE, IOWA
From 15-DEC-21 17:27:00 to 15-DEC-21 17:27:00 (CST-6)
Location: SCRANTON
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A personal weather station recorded a wind gust of 73 MPH.

Thunderstorm Wind in CARROLL, IOWA
From 15-DEC-21 17:27:00 to 15-DEC-21 17:27:00 (CST-6)
Location: COON RAPIDS
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in DECATUR, IOWA
From 15-DEC-21 17:27:00 to 15-DEC-21 17:27:00 (CST-6)
Location: (30I)LAMONI MUNI ARP
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:41:00 to 15-DEC-21 17:41:00 (CST-6)
Location: MINBURN
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Wind gusts of 60-70 MPH from amateur radio operators in Minburn.

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:41:00 to 15-DEC-21 17:41:00 (CST-6)
Location: PERRY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Wind gusts of 60 TO 70 MPH from amateur radio operators in Perry.

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:45:00 to 15-DEC-21 17:45:00 (CST-6)
Location: PERRY MUNI ARPT
Magnitude: 64.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:45:00 to 15-DEC-21 17:45:00 (CST-6)
Location: MINBURN
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Estimated gust of 75 MPH.

Thunderstorm Wind in UNION, IOWA
From 15-DEC-21 17:55:00 to 15-DEC-21 17:55:00 (CST-6)
Location: CRESTON ARPT
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:49:00 to 15-DEC-21 17:49:00 (CST-6)
Location: DALLAS CENTER ARPT
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reports 80 MPH winds at highway 169 and highway 44.

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:07:00 to 15-DEC-21 18:07:00 (CST-6)
Location: DODGE FLD ARPT
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in WEBSTER, IOWA
From 15-DEC-21 18:02:00 to 15-DEC-21 18:02:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in STORY, IOWA
From 15-DEC-21 18:08:00 to 15-DEC-21 18:08:00 (CST-6)
Location: AMES ARPT
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in STORY, IOWA
From 15-DEC-21 18:13:00 to 15-DEC-21 18:13:00 (CST-6)
Location: GILBERT
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter estimated 70 mph winds.

Thunderstorm Wind in MADISON, IOWA
From 15-DEC-21 18:19:00 to 15-DEC-21 18:19:00 (CST-6)
Location: WINTERSET ARPT
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in KOSSUTH, IOWA
From 15-DEC-21 18:15:00 to 15-DEC-21 18:15:00 (CST-6)
Location: ALGONA MUNI ARPT
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:27:00 to 15-DEC-21 18:27:00 (CST-6)
Location: (DSM)DES MOINES INTL
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:27:00 to 15-DEC-21 18:27:00 (CST-6)
Location: DODGE FLD ARPT
Magnitude: 65.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in CARROLL, IOWA
From 15-DEC-21 17:31:00 to 15-DEC-21 17:31:00 (CST-6)
Location: RALSTON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Wind estimates of at least 70 mph from Ralston Fire Dept. Sporadic damage reported.

Thunderstorm Wind in DECATUR, IOWA
From 15-DEC-21 18:25:00 to 15-DEC-21 18:25:00 (CST-6)
Location: (30I)LAMONI MUNI ARP
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in CLARKE, IOWA
From 15-DEC-21 18:29:00 to 15-DEC-21 18:29:00 (CST-6)
Location: OSCEOLA MUNI ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:35:00 to 15-DEC-21 18:35:00 (CST-6)
Location: SWANWOOD
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 18:17:00 to 15-DEC-21 18:17:00 (CST-6)
Location: ORTONVILLE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Former NWS employee estimated 70 mph winds and reported brief power outage.

Thunderstorm Wind in FRANKLIN, IOWA
From 15-DEC-21 18:38:00 to 15-DEC-21 18:38:00 (CST-6)
Location: HAMPTON
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in LUCAS, IOWA
From 15-DEC-21 18:48:00 to 15-DEC-21 18:48:00 (CST-6)
Location: CHARITON MUNI ARPT
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in CERRO GORDO, IOWA
From 15-DEC-21 18:53:00 to 15-DEC-21 18:53:00 (CST-6)
Location: (MCW)MASON CITY MUNI
Magnitude: 72.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in MARION, IOWA
From 15-DEC-21 18:55:00 to 15-DEC-21 18:55:00 (CST-6)
Location: KNOXVILLE ARPT
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in MARION, IOWA
From 15-DEC-21 19:15:00 to 15-DEC-21 19:15:00 (CST-6)
Location: PELLA MUNI ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in BLACK HAWK, IOWA
From 15-DEC-21 19:34:00 to 15-DEC-21 19:34:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in JASPER, IOWA
From 15-DEC-21 19:31:00 to 15-DEC-21 19:31:00 (CST-6)
Location: PRAIRIE CITY
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in BLACK HAWK, IOWA
From 15-DEC-21 19:36:00 to 15-DEC-21 19:36:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in MAHASKA, IOWA
From 15-DEC-21 19:52:00 to 15-DEC-21 19:52:00 (CST-6)
Location: OSKALOOSA MUNI ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in WAPELLO, IOWA
From 15-DEC-21 19:54:00 to 15-DEC-21 19:54:00 (CST-6)
Location: (OTM)OTTUMWA INDSTRL
Magnitude: 71.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in APPANOOSE, IOWA
From 15-DEC-21 19:27:00 to 15-DEC-21 19:27:00 (CST-6)
Location: CENTERVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Wind gusts of 60-70 mph near Centerville reported via social media. Time estimated via radar.

Thunderstorm Wind in PALO ALTO, IOWA
From 15-DEC-21 17:45:00 to 15-DEC-21 17:45:00 (CST-6)
Location: RUTHVEN
Magnitude: 61.00 EG
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported hog building completely destroyed.

Thunderstorm Wind in PALO ALTO, IOWA
From 15-DEC-21 17:45:00 to 15-DEC-21 17:45:00 (CST-6)
Location: OSGOOD
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported damage to outbuilding and trees uprooted. Time estimated from radar.

Thunderstorm Wind in RINGGOLD, IOWA
From 15-DEC-21 17:51:00 to 15-DEC-21 17:51:00 (CST-6)
Location: MT AYR
Magnitude: 56.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Public

Metal roof peeled off on the TEK Builders building in Mount Ayr. This is a delayed report, time estimated from radar.

Thunderstorm Wind in UNION, IOWA
From 15-DEC-21 17:56:00 to 15-DEC-21 17:56:00 (CST-6)
Location: CRESTON
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported a tree down on a powerline and house. Time estimated from radar.

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:12:00 to 15-DEC-21 18:12:00 (CST-6)
Location: WEST DES MOINES
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported wind gusts between 612 pm and 625 pm, estimated between 60 and 70 pm. Also reported large branches down, but exact size unknown.

Thunderstorm Wind in KOSSUTH, IOWA
From 15-DEC-21 18:15:00 to 15-DEC-21 18:15:00 (CST-6)
Location: ALGONA
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported 14 inch diameter tree on a house.

Thunderstorm Wind in CLARKE, IOWA
From 15-DEC-21 18:18:00 to 15-DEC-21 18:18:00 (CST-6)
Location: OSCEOLA
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported trees down on power lines in Osceola. Time estimated from radar.

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:20:00 to 15-DEC-21 18:20:00 (CST-6)
Location: WINDSOR HGTS
Magnitude: 56.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported large tree down on a house in Clive. Time estimated from radar.

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:23:00 to 15-DEC-21 18:23:00 (CST-6)
Location: LOVINGTON
Magnitude: 52.00 EG
Crop damage: 0.00K
Reported by: Public

Public reported siding, shingle, and minor tree damage to townhomes. Report was relayed via broadcast media. Time estimated from radar.

Thunderstorm Wind in WRIGHT, IOWA
From 15-DEC-21 18:25:00 to 15-DEC-21 18:25:00 (CST-6)
Location: BELMOND
Magnitude: 61.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported 3 to 4 outbuildings completely destroyed near Belmond. Time estimated from radar.

Thunderstorm Wind in STORY, IOWA
From 15-DEC-21 18:27:00 to 15-DEC-21 18:27:00 (CST-6)
Location: MAXWELL
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Public reported large tree on a home. Time estimated from radar.

Thunderstorm Wind in POLK, IOWA
From 15-DEC-21 18:28:00 to 15-DEC-21 18:28:00 (CST-6)
Location: FT DES MOINES
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Broadcast media relayed public report of telephone pole damage at Wakonda Club Golf Course. Time estimated from radar.

Thunderstorm Wind in DALLAS, IOWA
From 15-DEC-21 17:39:00 to 15-DEC-21 17:39:00 (CST-6)
Location: LINDEN
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A personal weather station recorded a wind gust of 62 MPH.

Tornado in WRIGHT, IOWA
From 15-DEC-21 18:25:00 to 15-DEC-21 18:30:00 (CST-6)
Location: ROWAN
Tornado F-scale: EF1
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado went through three counties including Wright, Franklin and Cerro Gordo.  The tornado touched down just north of Rowan and moved northeast through rural eastern Wright county before crossing into Franklin County several miles northwest of Alexander. The tornado produced little damage in Wright County although some tree damage occurred just prior to crossing into Franklin County.  This tornado was also found in high resolution satellite imagery.

Tornado in HANCOCK, IOWA
From 15-DEC-21 18:29:00 to 15-DEC-21 18:32:00 (CST-6)
Location: KANAWHA
Tornado F-scale: EF0
Property damage: 0.50K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado moved from Wright County into Hancock County.  Evidence for the tornado was from high resolution satellite imagery and correlation coefficient depression on the WSR-88D radar located in Johnston, IA.  There was also some minor tree damage near West Twin Lake in southern Hancock County.  The tornado continued northeast for about two more miles past the lake before dissipating.

Thunderstorm Wind in CERRO GORDO, IOWA
From 15-DEC-21 18:48:00 to 15-DEC-21 18:48:00 (CST-6)
Location: MASON CITY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported multiple 3 inch diameter or greater tree branches down. Time estimated from radar.

Thunderstorm Wind in WORTH, IOWA
From 15-DEC-21 18:55:00 to 15-DEC-21 18:55:00 (CST-6)
Location: MANLY
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported damage to shed or outbuilding east of Manly. Time estimated from radar.

Thunderstorm Wind in MARION, IOWA
From 15-DEC-21 19:05:00 to 15-DEC-21 19:05:00 (CST-6)
Location: PELLA
Magnitude: 52.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

Public reported large limbs down and metal roof blown off. Time estimated from radar.

Thunderstorm Wind in MARSHALL, IOWA
From 15-DEC-21 19:15:00 to 15-DEC-21 19:15:00 (CST-6)
Location: DUNBAR
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Public

Public reported snapped power poles. Time estimated from radar.

Thunderstorm Wind in APPANOOSE, IOWA
From 15-DEC-21 19:20:00 to 15-DEC-21 19:20:00 (CST-6)
Location: CENTERVILLE
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

Public reported a large tree partially uprooted and on a home. Metal building flipped. Time estimated from radar.

Thunderstorm Wind in POWESHIEK, IOWA
From 15-DEC-21 19:25:00 to 15-DEC-21 19:25:00 (CST-6)
Location: GRINNELL ARPT
Magnitude: 56.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported 2 semis overturned on Interstate 80 WB near the 185 to 186 mile markers. Just east of Grinnell.

Thunderstorm Wind in MARSHALL, IOWA
From 15-DEC-21 22:39:00 to 15-DEC-21 22:39:00 (CST-6)
Location: MARSHALLTOWN ARPT
Magnitude: 70.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Marshalltown ASOS measured a 70 kt or 81 mph wind gust.

Thunderstorm Wind in KOSSUTH, IOWA
From 15-DEC-21 22:55:00 to 15-DEC-21 22:55:00 (CST-6)
Location: ALGONA MUNI ARPT
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Algona AWOS recorded a 63 mph wind gust.

Thunderstorm Wind in BLACK HAWK, IOWA
From 15-DEC-21 22:37:00 to 15-DEC-21 22:37:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo ASOS recorded a 58 mph wind gust.

Thunderstorm Wind in BLACK HAWK, IOWA
From 15-DEC-21 23:17:00 to 15-DEC-21 23:17:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo ASOS recorded a 62 mph wind gust.

Thunderstorm Wind in ADAIR, IOWA
From 15-DEC-21 17:12:00 to 15-DEC-21 17:12:00 (CST-6)
Location: ADAIR
Magnitude: 66.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A personal weather station recorded a 76 MPH wind gust.

Thunderstorm Wind in AUDUBON, IOWA
From 15-DEC-21 17:11:00 to 15-DEC-21 17:11:00 (CST-6)
Location: AUDUBON
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A personal weather station reported a gust of 88 MPH.

Thunderstorm Wind in WARREN, IOWA
From 15-DEC-21 18:36:00 to 15-DEC-21 18:36:00 (CST-6)
Location: INDIANOLA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported numerous trees down blocking Highways 65/69/S. Jefferson Way near the 700 block. Other trees down in Indianola as well.

Thunderstorm Wind in WARREN, IOWA
From 15-DEC-21 18:37:00 to 15-DEC-21 18:37:00 (CST-6)
Location: INDIANOLA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Local trained spotters reported numerous trees down and wind gusts of 65-70 mph.

Thunderstorm Wind in CERRO GORDO, IOWA
From 15-DEC-21 18:40:00 to 15-DEC-21 18:40:00 (CST-6)
Location: SWALEDALE
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy damage to machine sheds and out buildings.

Thunderstorm Wind in BUTLER, IOWA
From 15-DEC-21 18:47:00 to 15-DEC-21 18:47:00 (CST-6)
Location: BRISTOW
Magnitude: 61.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported one outbuilding leveled and another missing the north wall. Time estimated from radar.

Tornado in CRAWFORD, IOWA
From 15-DEC-21 16:48:00 to 15-DEC-21 16:51:00 (CST-6)
Location: DOW CITY
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

First tornado in the Des Moines forecast area for this record breaking event.  This tornado remained in rural Crawford county with no reported damage.  Tornado was determined by Correlation Coefficient depression on WSR-88D radar from KOAX.

Tornado in CASS, IOWA
From 15-DEC-21 16:49:00 to 15-DEC-21 16:59:00 (CST-6)
Location: LEWIS
Tornado F-scale: EF2
Property damage: 300.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed northwest of Lewis and moved rapidly to the northeast.  Damage occurred to several houses and trees along the path with mostly EF0 and EF1 ratings.  Three high voltage steel towers were toppled providing the EF2 rating for this tornado.  The tornado crossed Interstate 80 near milepost 59 blowing several semi onto their sides. The path was also observed in high resolution satellite imagery. This tornado then crossed into Audubon county.

Tornado in AUDUBON, IOWA
From 15-DEC-21 16:59:00 to 15-DEC-21 17:09:00 (CST-6)
Location: BRAYTON
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado continued into Audubon county from Cass county.  The tornado remains in rural portions of southern and central Audubon county.  Most damage was to farm outbuildings, trees and power poles with EF1 the highest damage rating observed.

Tornado in CASS, IOWA
From 15-DEC-21 17:00:00 to 15-DEC-21 17:01:00 (CST-6)
Location: LORAH
Tornado F-scale: EF0
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed northeast of Atlantic and crossed Interstate 80 flipping a semi on its side.  Tree damage was also noted near this location before crossing into Audubon county.

Tornado in AUDUBON, IOWA
From 15-DEC-21 17:01:00 to 15-DEC-21 17:09:00 (CST-6)
Location: BRAYTON
Tornado F-scale: EF1
Property damage: 75.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado moved into Audubon county from Cass county.  This tornado remained on the ground in rural areas of southeastern Audubon county.  Damage was primarily to trees with one garage being destroyed east of Exira producing an EF1 rating.

Tornado in GUTHRIE, IOWA
From 15-DEC-21 17:10:00 to 15-DEC-21 17:18:00 (CST-6)
Location: NORTH BRANCH
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed in west central Guthrie county and moved quickly northeast through rural portions of the county.  Two farm buildings were destroyed along State Highway 44 with additional outbuilding and house damage to the northeast with most ratings of EF1.  The tornado dissipated northeast of the hamlet of Wichita.

Tornado in CARROLL, IOWA
From 15-DEC-21 17:13:00 to 15-DEC-21 17:15:00 (CST-6)
Location: BREDA
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed in far northwest Carroll county west of Breda.  The path was observed in high resolution satellite imagery.  No damage was reported in Carroll county, hence the EFU rating.  This tornado continued into Sac county.

Tornado in SAC, IOWA
From 15-DEC-21 17:15:00 to 15-DEC-21 17:26:00 (CST-6)
Location: CARNARVON
Tornado F-scale: EF2
Property damage: 150.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado move into Sac county from Carroll county.  This tornado passed just on the southeast side of the hamlet of Carnarvon with EF1 damage from a destroyed outbuilding. The tornado continued northeast through rural south and east Sac county producing EF0 to EF1 damage to outbuildings and trees.  EF2 damage was observed when power poles were snapped along 310th street east of Union Avenue.  The tornado eventually lifted to the southwest of Lytton.

Tornado in GUTHRIE, IOWA
From 15-DEC-21 17:14:00 to 15-DEC-21 17:24:00 (CST-6)
Location: NORTH BRANCH
Tornado F-scale: EF2
Property damage: 350.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed in west central Guthrie county to the west southwest of Wichita.  The tornado moved northeast producing EF0 and EF1 damage to trees and outbuildings in rural portions of northwest Guthrie County.  The storm passed along the southeast edge of Bayard taking a roof off a house and demolishing a garage on another house.  This damage was rated EF2.  The tornado exited the county shortly thereafter into Greene County.

Thunderstorm Wind in MAHASKA, IOWA
From 15-DEC-21 19:16:00 to 15-DEC-21 19:16:00 (CST-6)
Location: OSKALOOSA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported 60 to 70 mph winds and power flashes.

Tornado in GREENE, IOWA
From 15-DEC-21 17:24:00 to 15-DEC-21 17:28:00 (CST-6)
Location: COOPER
Tornado F-scale: EF2
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado moved from Guthrie into Greene County.  The tornado destroyed several grain bins shortly after entering the county and then snapped several large power poles along 330th Street between F and G Avenues.   The tornado continued northeast producing sporadic damage in rural southern Greene County before dissipating north of 300th Street between H and I Avenues.

Tornado in CARROLL, IOWA
From 15-DEC-21 17:19:00 to 15-DEC-21 17:26:00 (CST-6)
Location: WILEY
Tornado F-scale: EF1
Property damage: 80.00K
Crop damage: 0.00K
Reported by: Social Media

Damage was obtained via social media.  The track was also observed near the Carroll Airport from high resolution satellite imagery.  There was damage to a home and outbuildings with up to EF1 damage.

Tornado in GREENE, IOWA
From 15-DEC-21 17:27:00 to 15-DEC-21 17:42:00 (CST-6)
Location: COOPER
Tornado F-scale: EF2
Property damage: 350.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado continued into Greene County from Guthrie County.  The path through Greene County was long but remained in rural portions of the county.  Damage to rural outbuildings occurred in southern Greene county with more intense damage south of Jefferson.  Utility poles were snapped along 280th Street near where N Avenue intersects the road.   The tornado then impacted a farmstead on the west side of Highway 4 destroying several outbuildings and producing minor damage to the home.  The tornado proceeded northeast crossing US Highway 30 east of Jefferson and then continued in rural areas before lifting north of Dana.

Tornado in GUTHRIE, IOWA
From 15-DEC-21 17:27:00 to 15-DEC-21 17:29:00 (CST-6)
Location: BAGLEY
Tornado F-scale: EF1
Property damage: 1.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed east southeast of Bagley and did no damage until near the county line where an aging power pole was snapped.  The tornado path was also visible in high resolution satellite imagery.  The tornado moved into Greene County.

Tornado in GREENE, IOWA
From 15-DEC-21 17:29:00 to 15-DEC-21 17:45:00 (CST-6)
Location: COOPER
Tornado F-scale: EF2
Property damage: 800.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado moved into Greene County from Guthrie County.  This tornado produced damage through rural south and east portions of the county.  The tornado passed just southeast of the hamlet of Cooper and through Grand Junction.  Most of the damage was EF0 to EF1 with tree and minor house damage.  However, the tornado strengthened north of Grand Junction with power pole damage and then toppling an industrial wind mill along W Avenue with an EF2 rating at that location.  The circulation then destroyed a confinement building before dissipating several miles northeast of Dana.

Tornado in GREENE, IOWA
From 15-DEC-21 17:29:00 to 15-DEC-21 17:33:00 (CST-6)
Location: SCRANTON
Tornado F-scale: EF2
Property damage: 1.20M
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado occurred southwest of Jefferson and remained in rural Greene County during its entire path.   The tornado damaged a confinement building and farther northeast destroyed an outbuilding.  However, the most intense damage was a series of high voltage utility dual pole towers which were snapped by the tornado.  At least 8 towers were snapped over J Avenue between 250th and 260th Streets.  Additional utility poles were snapped along 250th Street as well.   The tornado lifted in the vicinity of an apple orchard located southwest of Jefferson.

Tornado in GREENE, IOWA
From 15-DEC-21 17:32:00 to 15-DEC-21 17:36:00 (CST-6)
Location: SCRANTON
Tornado F-scale: EF2
Property damage: 500.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Another QLCS tornado which began west southwest of Jefferson and ended to the northwest of town.  This tornado began in rural areas but toppled several large single pole utility poles along I Avenue south of 250th Street and moved northeast with tree and minor house damage on 240th Street near the intersection with K Avenue.   The tornado ended up crossing US Highway 30 about 1.5 miles west of the intersection with State Highway 4 and severely leaned high voltage poles along the highway.  The tornado dissipated not long afterwards near M Avenue north of Highway 30.

Tornado in GREENE, IOWA
From 15-DEC-21 17:34:00 to 15-DEC-21 17:36:00 (CST-6)
Location: FARLIN
Tornado F-scale: EF2
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This was a relatively brief tornado but none the less strong as it snapped power poles along I Avenue south of 180th Street to the northwest of Farlin.  Otherwise, the tornado remained in rural areas of Greene County with no other reports of damage.

Tornado in CALHOUN, IOWA
From 15-DEC-21 17:34:00 to 15-DEC-21 17:35:00 (CST-6)
Location: WIGHTMAN
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was found via high resolution satellite imagery.  The short path did intersect a few places but no damage was discernable from the imagery, therefore an EFU rating.

Tornado in CALHOUN, IOWA
From 15-DEC-21 17:35:00 to 15-DEC-21 17:49:00 (CST-6)
Location: WIGHTMAN
Tornado F-scale: EF1
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This path was found via storm survey and extended using high resolution satellite imagery.  The storm started south southwest of Lohrville and passed just west of town producing mainly tree damage and some minor house damage.  The path continue northeast through eastern Calhoun county with additional damage to trees and outbuildings with path clearly evident in satellite imagery.  The tornado passed the east side of Knierim and dissipated not long afterwards.

Tornado in GREENE, IOWA
From 15-DEC-21 17:39:00 to 15-DEC-21 17:42:00 (CST-6)
Location: GRAND JCT
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado traveled through three counties and initially touched down in Greene county to the east northeast of Grand Junction.  This tornado remained in rural areas of Greene county with no damage reports received.  The tornado path was observed using high resolution satellite imagery as well.  The tornado moved into Boone County between 190th and 180th Streets.

Tornado in BOONE, IOWA
From 15-DEC-21 17:42:00 to 15-DEC-21 17:49:00 (CST-6)
Location: BEAVER
Tornado F-scale: EF1
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado entered Boone County from Greene County.  This tornado moved quickly northeast through the northwest corner of Boone County passing just south and east of Boxholm.  Damage was relatively limited along the both but there was some impressive tree damage south of Boxholm where the EF1 damage was observed.  The tornado moved into Webster County to the northeast of Boxholm.

Tornado in WEBSTER, IOWA
From 15-DEC-21 17:49:00 to 15-DEC-21 17:52:00 (CST-6)
Location: DAYTON
Tornado F-scale: EF2
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado moved into Webster County from Boone County.  It remained in rural areas of southeast Webster County producing tree and utility pole damage.  EF2 damage was incurred to the southeast of Dayton along State Highway 175 where 8 utility poles were snapped.  The tornado then moved into the Des Moines River  east of Dayton valley where it dissipated.

Tornado in CALHOUN, IOWA
From 15-DEC-21 17:40:00 to 15-DEC-21 17:49:00 (CST-6)
Location: FARNHAMVILLE
Tornado F-scale: EF2
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado had a path in both Calhoun and Webster Counties.  The path started west northwest of Farnhamville with the tornado heading north northeast passing on the east side of Somers.  There was EF2 damage observed to the east southeast of Rinard where large utility poles were snapped.  Additional tree and barn damage was observed south of Somers.  The path continued top the northeast before exiting the county into Webster County just south of US Highway 20.

Tornado in WEBSTER, IOWA
From 15-DEC-21 17:49:00 to 15-DEC-21 17:54:00 (CST-6)
Location: ROELYN
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado continued into Webster County from Calhoun County.  This tornado entered the county near US Highway 20 and continued northeast through the east side of Barnum.  Most minor damage to houses occurred along with tree damage.  The tornado dissipated to the northeast of Barnum near Lizard Creek.

Tornado in PALO ALTO, IOWA
From 15-DEC-21 17:41:00 to 15-DEC-21 17:50:00 (CST-6)
Location: AYRSHIRE
Tornado F-scale: EF1
Property damage: 60.00K
Crop damage: 0.00K
Reported by: Public

Path of damage began a couple miles northeast of Ayrshire and moved north northeast, dissipating to the southeast of Graettinger.  Along the path, several trees were damage along with a roof off of an outbuilding along with power pole damage.

Tornado in GREENE, IOWA
From 15-DEC-21 17:42:00 to 15-DEC-21 17:46:00 (CST-6)
Location: PATON
Tornado F-scale: EF2
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado moved through both Greene and Webster Counties.  The tornado developed southwest of Paton in Greene County and blew apart an old shed.  It continued to strengthen and snapped several large utility poles along 110th Street west of U Avenue.  The tornado then exited the county into Webster County north of Paton.

Tornado in WEBSTER, IOWA
From 15-DEC-21 17:46:00 to 15-DEC-21 17:57:00 (CST-6)
Location: LENA
Tornado F-scale: EF2
Property damage: 200.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado moved into Webster County from Greene County.  The tornado entered the county southwest of Lanyon and passed just west of Harcourt continuing northeast before dissipating between Lehigh and Otho.   This tornado snapped several large utility poles on its path across the county along with destroying a few outbuildings.

Tornado in POCAHONTAS, IOWA
From 15-DEC-21 17:43:00 to 15-DEC-21 17:44:00 (CST-6)
Location: BLANDEN
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was discovered using high resolution satellite imagery combined with radar data.  There was no damaged observed with this tornado, hence the EFU rating.

Tornado in BOONE, IOWA
From 15-DEC-21 17:49:00 to 15-DEC-21 17:54:00 (CST-6)
Location: WOLF
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado passed through three counties including Boone, Webster and Hamilton.  The tornado touched down south of Pilot Mound in Boone County with this portion of the path documented via high resolution satellite imagery.  However, there was observed damage just before crossing into Webster county with damage to an outbuilding along 105th Street.  The tornado then exited into Webster County.

Tornado in WEBSTER, IOWA
From 15-DEC-21 17:54:00 to 15-DEC-21 17:55:00 (CST-6)
Location: DAYTON
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This portion of the path just clipped the far southeast corner of Webster county without producing any damage, hence the EFU rating.  The tornado moved from Boone County into Webster County, then from Webster County into Hamilton County.

Tornado in HAMILTON, IOWA
From 15-DEC-21 17:55:00 to 15-DEC-21 18:01:00 (CST-6)
Location: STRATFORD
Tornado F-scale: EF2
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado entered Hamilton County from Webster County.  The tornado produced damage to multiple large utility poles along several county roads to the south and east of Stratford.  The tornado finally lifted northwest of Stanhope as it approached the Boone River valley.

Tornado in POCAHONTAS, IOWA
From 15-DEC-21 17:50:00 to 15-DEC-21 17:55:00 (CST-6)
Location: PALMER
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado moved through both Pocahontas and Humboldt Counties.  Tornado path found via high resolution satellite imagery and radar data.  No damage was reported, hence the EFU rating.  The tornado passed just west and north of Gilmore City, entering into Humboldt County north of Gilmore City.

Tornado in HUMBOLDT, IOWA
From 15-DEC-21 17:55:00 to 15-DEC-21 17:56:00 (CST-6)
Location: GILMORE
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado entered Humboldt County from Pocahontas County.  This path was observed via high resolution satellite imagery in collaboration with radar data.  No damage was reported, hence the EFU designation.

Tornado in WEBSTER, IOWA
From 15-DEC-21 17:55:00 to 15-DEC-21 17:56:00 (CST-6)
Location: DAYTON
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado travelled through both Webster and Hamilton Counties.  This short section in Webster County produced no reportable damage but was observed via high resolution satellite imagery.   The tornado moved into Hamilton County south of Stratford.

Tornado in HAMILTON, IOWA
From 15-DEC-21 17:56:00 to 15-DEC-21 18:05:00 (CST-6)
Location: STRATFORD
Tornado F-scale: EF2
Property damage: 180.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado entered Hamilton County from Webster County just south of Stratford and passed just south and east of town.  This produced tree damage and completely destroyed an outbuilding northeast of town.  The tornado continued to produce damage northeast of Stratford to outbuildings and trees before entering the Boone River valley and dissipating south several miles south of Webster City.

Tornado in HUMBOLDT, IOWA
From 15-DEC-21 17:58:00 to 15-DEC-21 18:01:00 (CST-6)
Location: RUTLAND
Tornado F-scale: EF1
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Trained Spotter

This tornado started a few miles northwest of Rutland and moved northeast through rural portions of Humboldt County.  The tornado snapped several large utility poles along Iowa Avenue south of Bode before lifting.

Tornado in WEBSTER, IOWA
From 15-DEC-21 18:00:00 to 15-DEC-21 18:04:00 (CST-6)
Location: EVANSTON
Tornado F-scale: EF2
Property damage: 75.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado started on the east side of the Des Moines River valley southwest of Duncombe and moved quickly northeast.  The tornado snapped several power poles near the intersection of Taylor Avenue and 220th Street west of Duncombe. Another outbuilding was destroyed northwest of Duncombe near the intersection of 210th Street and the Canadian National Railway.  The tornado lifted not long afterwards.

Tornado in HAMILTON, IOWA
From 15-DEC-21 18:01:00 to 15-DEC-21 18:08:00 (CST-6)
Location: STANHOPE
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was discovered using high resolution satellite imagery.   There was some minor damage to trees and outbuildings along the path of this tornado through Hamilton County.

Tornado in WEBSTER, IOWA
From 15-DEC-21 18:01:00 to 15-DEC-21 18:03:00 (CST-6)
Location: BRUSHY
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado was discovered using high resolution satellite imagery.  The tornado started just east of the Brushy Creek State Preserve with a short path in rural Webster County before crossing into Hamilton County.  No damage was reported in Webster County, hence the EFU rating for this segment.

Tornado in HAMILTON, IOWA
From 15-DEC-21 18:03:00 to 15-DEC-21 18:07:00 (CST-6)
Location: HOMER
Tornado F-scale: EF0
Property damage: 70.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado moved into Hamilton County from Webster County.   This tornado moved northeast through rural portions of Hamilton county southwest and west of Webster City.  The tornado passed over the US Highway 20 interchange with Stagecoach Road and then did damage to an industrial plant along 220th Street to the west of Webster City.  The tornado dissipated a short time later.

Tornado in WRIGHT, IOWA
From 15-DEC-21 18:19:00 to 15-DEC-21 18:23:00 (CST-6)
Location: GALT
Tornado F-scale: EF2
Property damage: 150.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado develop several miles southwest of Galt producing damage to a couple different confinement operations.  Buildings were completely destroyed at one operation along 250th Street producing EF2 damage.  The tornado continued northeast with additional damage to outbuildings before dissipating to the west southwest of Rowan.

Tornado in FRANKLIN, IOWA
From 15-DEC-21 18:30:00 to 15-DEC-21 18:34:00 (CST-6)
Location: ALEXANDER
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado continued into Franklin County from Wright County.  The tornado continued on a northeast track through the far northwest corner of Franklin County with no reports of damage, hence the EFU rating.  This tornado moved into Cerro Gordo County about a mile east of Meservey.

Tornado in CERRO GORDO, IOWA
From 15-DEC-21 18:34:00 to 15-DEC-21 18:38:00 (CST-6)
Location: MESERVEY
Tornado F-scale: EF2
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado moved into Cerro Gordo County from Franklin County.  The tornado produced damage to several farmsteads, mainly to the outbuildings with a couple of outbuildings destroyed northeast of Meservey.  The tornado eventually dissipated several miles west of Swaledale.

Tornado in HARDIN, IOWA
From 15-DEC-21 18:26:00 to 15-DEC-21 18:28:00 (CST-6)
Location: IOWA FALLS
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado moved through both Hardin and Franklin Counties.  The tornado touched down in Hardin County north of Alden and moved quickly northeast.  The tornado exited Hardin County into Franklin County near the intersection of Hardin Road and HH Avenue.  The Hardin County segment was found and determined by using high resolution satellite imagery.

Tornado in FRANKLIN, IOWA
From 15-DEC-21 18:28:00 to 15-DEC-21 18:35:00 (CST-6)
Location: BURDETTE
Tornado F-scale: EF1
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado moved into Franklin County from Hardin County.  Much of the path through Franklin County was found using high resolution satellite imagery.  However, the emergency manager did supply some damage points on the northeast end of the track to the northeast of Bradford, Iowa.  The damage was to trees with tree trunks being snapped along several different roads.  The tornado lifted a few miles west southwest of Geneva.

Tornado in HARDIN, IOWA
From 15-DEC-21 18:27:00 to 15-DEC-21 18:32:00 (CST-6)
Location: IOWA FALLS MUNI ARPT
Tornado F-scale: EF1
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

This tornado travelled through both Hardin and Franklin Counties.  The tornado touched down about two miles south of Iowa Falls and passed on the southeast edges of the town.  This produced some EF1 damage to buildings in the area.  The tornado continued to the northeast and crossed into Franklin County near the intersection of Hardin Road and county highway S45.