After a cold front stalled out across northwest Iowa the previous night, much of Iowa was firmly within the warm sector of an approaching surface low. As a result, winds were strong out of the south, helping keep dew points in the mid to upper 60s. While temperatures were only in the 70s, with the relatively high dew points SBCAPE values were able to eclipse 2000 J/kg in an uncapped environment.  Storms began to initiate in the early afternoon, primarily producing funnel clouds and hail.  As a weak boundary ahead of the parent cold front moved through, storms organized linearly and became primary wind gust and damaging wind producers as they traveled north/northeast.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:15:00 to 17-MAY-17 15:15:00 (CST-6)
Location: CLIVE
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

KCCI School Net recorded a 59 mph wind gust.

Hail in MONROE, IOWA
From 17-MAY-17 15:15:00 to 17-MAY-17 15:15:00 (CST-6)
Location: HOCKING
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported quarter sized hail.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:16:00 to 17-MAY-17 15:16:00 (CST-6)
Location: FT DES MOINES
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

KCCI School Net site recorded a 59 mph wind gust.

Thunderstorm Wind in WARREN, IOWA
From 17-MAY-17 15:18:00 to 17-MAY-17 15:18:00 (CST-6)
Location: NORWALK
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported wind gusts of 60 to 70 mph.

Thunderstorm Wind in WARREN, IOWA
From 17-MAY-17 15:20:00 to 17-MAY-17 15:20:00 (CST-6)
Location: ACKWORTH
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported tree damage, wind speeds unknown at the time.  Time estimated by radar.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:21:00 to 17-MAY-17 15:21:00 (CST-6)
Location: HERROLD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee reported tree branches down on Beaver Dr and power outages in Johnston.

Thunderstorm Wind in KOSSUTH, IOWA
From 17-MAY-17 15:21:00 to 17-MAY-17 15:21:00 (CST-6)
Location: BURT
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported 70 to 80 estimated wind gusts.  Time estimated by radar.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:25:00 to 17-MAY-17 15:25:00 (CST-6)
Location: URBANDALE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported large tree split near its base and landed across the roadway.  Time estimated by radar and this is a delayed report.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:28:00 to 17-MAY-17 15:28:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter estimated wind gusts to around 60 mph, with minor tree damage in the area.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:30:00 to 17-MAY-17 15:30:00 (CST-6)
Location: ALTOONA
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Altoona RWIS measured wind gusts to 58 mph.

Thunderstorm Wind in JASPER, IOWA
From 17-MAY-17 15:39:00 to 17-MAY-17 15:39:00 (CST-6)
Location: MONROE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported wind gusts to 70 mph.

Thunderstorm Wind in JASPER, IOWA
From 17-MAY-17 15:40:00 to 17-MAY-17 15:40:00 (CST-6)
Location: COLFAX
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported strong winds to 60 mph with heavy rainfall approaching.

Hail in MONROE, IOWA
From 17-MAY-17 15:20:00 to 17-MAY-17 15:20:00 (CST-6)
Location: HOCKING
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported nickel size hail in southern Monroe County.

Funnel Cloud in MONROE, IOWA
From 17-MAY-17 15:20:00 to 17-MAY-17 15:20:00 (CST-6)
Location: HOCKING
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in POWESHIEK, IOWA
From 17-MAY-17 16:25:00 to 17-MAY-17 16:25:00 (CST-6)
Location: GRINNELL ARPT
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Marshalltown airport AWOS recorded 68 mph wind gust.

Thunderstorm Wind in GRUNDY, IOWA
From 17-MAY-17 16:30:00 to 17-MAY-17 16:30:00 (CST-6)
Location: HOLLAND
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported outbuilding blown apart.  Report via social media and is a delayed report.

Thunderstorm Wind in WEBSTER, IOWA
From 17-MAY-17 16:13:00 to 17-MAY-17 16:13:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Some medium to large limbs were downed by the winds.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:13:00 to 17-MAY-17 16:13:00 (CST-6)
Location: ALBION
Magnitude: 60.00 MG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Emergency Manager reported grain bins destroyed and roof damage to a house.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:03:00 to 17-MAY-17 16:13:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 60.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported roof damage to a farmstead and a barn blown down near the Marshalltown airport.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:11:00 to 17-MAY-17 15:11:00 (CST-6)
Location: HADDEN HILL
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Five to six inch tree branches down near the road.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:24:00 to 17-MAY-17 15:24:00 (CST-6)
Location: SAYLORVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A 65 mph gust was measured on a home weather station, and 3 inch tree branches were reported down.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 16:51:00 to 17-MAY-17 16:51:00 (CST-6)
Location: CEDAR FALLS JCT
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A 65 mph wind gust was recorded at a home weather station.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:12:00 to 17-MAY-17 16:12:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 56.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A 3 foot diameter tree was uprooted.

Thunderstorm Wind in ADAIR, IOWA
From 17-MAY-17 14:35:00 to 17-MAY-17 14:35:00 (CST-6)
Location: ORIENT
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong winds to 60 mph estimated with tree limbs down in town.

Thunderstorm Wind in WAPELLO, IOWA
From 17-MAY-17 16:35:00 to 17-MAY-17 16:35:00 (CST-6)
Location: AGENCY
Magnitude: 51.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported an estimated gust of around 60 mph.

Thunderstorm Wind in STORY, IOWA
From 17-MAY-17 15:44:00 to 17-MAY-17 15:44:00 (CST-6)
Location: AMES
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported strong winds to around 60 mph or more.

Thunderstorm Wind in MARION, IOWA
From 17-MAY-17 15:38:00 to 17-MAY-17 15:38:00 (CST-6)
Location: PLEASANTVILLE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large willow tree downed in the yard.

Funnel Cloud in CALHOUN, IOWA
From 17-MAY-17 12:10:00 to 17-MAY-17 12:10:00 (CST-6)
Location: KNOKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported a funnel cloud via social media.

Funnel Cloud in SAC, IOWA
From 17-MAY-17 12:40:00 to 17-MAY-17 12:40:00 (CST-6)
Location: NEMAHA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported funnel cloud via social media.

Funnel Cloud in TAMA, IOWA
From 17-MAY-17 13:40:00 to 17-MAY-17 13:40:00 (CST-6)
Location: TRAER MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported funnel cloud via social media.

Hail in DALLAS, IOWA
From 17-MAY-17 13:48:00 to 17-MAY-17 13:48:00 (CST-6)
Location: ORTONVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 16:47:00 to 17-MAY-17 16:47:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public estimated wind gusts to at least 70 mph.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:47:00 to 17-MAY-17 16:47:00 (CST-6)
Location: ALLISON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager estimated wind gusts to 70 mph.

Hail in WAPELLO, IOWA
From 17-MAY-17 16:49:00 to 17-MAY-17 16:49:00 (CST-6)
Location: ELDON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Local fire department estimated hail nickel to quarter in size.

Hail in DALLAS, IOWA
From 17-MAY-17 13:55:00 to 17-MAY-17 13:55:00 (CST-6)
Location: DALLAS CENTER ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported quarter sized hail.

Hail in POLK, IOWA
From 17-MAY-17 14:08:00 to 17-MAY-17 14:08:00 (CST-6)
Location: DODGE FLD ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in DALLAS, IOWA
From 17-MAY-17 13:50:00 to 17-MAY-17 13:50:00 (CST-6)
Location: ADEL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in POLK, IOWA
From 17-MAY-17 14:10:00 to 17-MAY-17 14:10:00 (CST-6)
Location: GRIMES
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Thunderstorm Wind in WEBSTER, IOWA
From 17-MAY-17 16:00:00 to 17-MAY-17 16:00:00 (CST-6)
Location: FT DODGE
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

RWIS station near Fort Dodge on US 20 recorded a 59 mph wind gust.

Thunderstorm Wind in MAHASKA, IOWA
From 17-MAY-17 15:45:00 to 17-MAY-17 15:45:00 (CST-6)
Location: OSKALOOSA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported large tree downed in town.  Report via social media and is a delayed report.

Lightning in STORY, IOWA
From 17-MAY-17 16:00:00 to 17-MAY-17 16:00:00 (CST-6)
Location: ROLAND
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported a lightning strike that hit a tree, resulting in the tree falling onto and damaging the house.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:08:00 to 17-MAY-17 16:08:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported several large trees down.

Thunderstorm Wind in BREMER, IOWA
From 17-MAY-17 17:00:00 to 17-MAY-17 17:00:00 (CST-6)
Location: PLAINFIELD
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

RWIS near Plainfield recorded a 65 mph wind gust.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:53:00 to 17-MAY-17 16:53:00 (CST-6)
Location: PARKERSBURG
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio reported wind gusts to 70 mph.

Thunderstorm Wind in UNION, IOWA
From 17-MAY-17 14:20:00 to 17-MAY-17 14:20:00 (CST-6)
Location: CRESTON ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Creston AWOS station recorded a 60 mph wind gust.

Hail in POLK, IOWA
From 17-MAY-17 14:22:00 to 17-MAY-17 14:22:00 (CST-6)
Location: POLK CITY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in BLACK HAWK, IOWA
From 17-MAY-17 14:15:00 to 17-MAY-17 14:15:00 (CST-6)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Thunderstorm Wind in BREMER, IOWA
From 17-MAY-17 14:28:00 to 17-MAY-17 14:28:00 (CST-6)
Location: TRIPOLI
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported 4 inch diameter tree limbs down.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:11:00 to 17-MAY-17 16:11:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported wind gusts to 60 mph.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:19:00 to 17-MAY-17 16:19:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

RWIS on Highway 30 measured wind gusts to 59 mph.

Hail in MADISON, IOWA
From 17-MAY-17 13:35:00 to 17-MAY-17 13:35:00 (CST-6)
Location: WINTERSET
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in MADISON, IOWA
From 17-MAY-17 14:55:00 to 17-MAY-17 14:55:00 (CST-6)
Location: WINTERSET
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Small to medium limbs down in town.

Thunderstorm Wind in BREMER, IOWA
From 17-MAY-17 14:30:00 to 17-MAY-17 14:30:00 (CST-6)
Location: SCHWERIN FLD ARPT
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported estimated 65 mph wind gusts.

Thunderstorm Wind in UNION, IOWA
From 17-MAY-17 14:39:00 to 17-MAY-17 14:39:00 (CST-6)
Location: CRESTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree and tree limb damage in Creston.

Thunderstorm Wind in UNION, IOWA
From 17-MAY-17 14:30:00 to 17-MAY-17 14:30:00 (CST-6)
Location: CRESTON
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Iowa DOT RWIS site recorded a 64 mph wind gust.

Hail in STORY, IOWA
From 17-MAY-17 14:50:00 to 17-MAY-17 14:50:00 (CST-6)
Location: AMES
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Storm chaser reported penny sized hail.

Thunderstorm Wind in WARREN, IOWA
From 17-MAY-17 15:07:00 to 17-MAY-17 15:07:00 (CST-6)
Location: CUMMING
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Public reported shingles blown off homes.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:14:00 to 17-MAY-17 15:14:00 (CST-6)
Location: (DSM)DES MOINES INTL
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Des Moines International Airport ASOS recorded a 60 mph wind gust.

Thunderstorm Wind in CRAWFORD, IOWA
From 17-MAY-17 15:00:00 to 17-MAY-17 15:00:00 (CST-6)
Location: MANILLA
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported damage to an outbuilding.

Thunderstorm Wind in LUCAS, IOWA
From 17-MAY-17 15:15:00 to 17-MAY-17 15:15:00 (CST-6)
Location: CHARITON MUNI ARPT
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Chariton AWOS recorded a 61 mph wind gust.

Thunderstorm Wind in WARREN, IOWA
From 17-MAY-17 15:18:00 to 17-MAY-17 15:18:00 (CST-6)
Location: CUMMING
Magnitude: 56.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported semi blown over on I-35 at mile marker 65.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:19:00 to 17-MAY-17 15:19:00 (CST-6)
Location: GRIMES
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee reported wind gusts to 70 mph. Trees and large branches were down around town.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:25:00 to 17-MAY-17 15:25:00 (CST-6)
Location: DES MOINES
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported evacuation of tall buildings in Capital Square underway. Very strong winds downtown, estimated around 70 mph.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:18:00 to 17-MAY-17 15:18:00 (CST-6)
Location: ASHAWA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported tree damage including 6 to 12 inch diameter limbs torn off main trunk.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:19:00 to 17-MAY-17 15:19:00 (CST-6)
Location: DALLAS CENTER
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported power lines down between Dallas Center and Grimes.  Dallas Center without power at the time of the report.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:25:00 to 17-MAY-17 15:40:00 (CST-6)
Location: URBANDALE
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager stated dozens of reports of power lines down, trees down, power outages from transformer damage, and motor vehicle crashes all suspected to be storm related.  Metro wide reports too numerous to report.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 16:53:00 to 17-MAY-17 16:53:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 56.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

Public reported a tree fell on their house.  Time estimated by radar.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:14:00 to 17-MAY-17 16:14:00 (CST-6)
Location: ALBION
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported doors blown off machine shed and large branches down.

Thunderstorm Wind in GRUNDY, IOWA
From 17-MAY-17 16:28:00 to 17-MAY-17 16:28:00 (CST-6)
Location: GRUNDY CENTER
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported 1 to 2 foot diameter trees down near the courthouse. Report via social media and is a delayed report.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 16:38:00 to 17-MAY-17 16:38:00 (CST-6)
Location: EAGLE CENTER
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported tree across IA-175 blocking road east of Reinbeck between T69 and D46.  Time estimated by radar and is a delayed report.

Thunderstorm Wind in HANCOCK, IOWA
From 17-MAY-17 17:00:00 to 17-MAY-17 17:00:00 (CST-6)
Location: GARNER
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported a large tree fell on a house and damage was done to a fence in town.  Tree was 1 to 2 feet in diameter.  Reported via social media and is a delayed report.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 17:18:00 to 17-MAY-17 17:18:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager estimated 6 inch diameter tree limb down pinning people in a car.  Numerous locations in North Waterloo with smaller limbs down on streets and cars.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:45:00 to 17-MAY-17 16:45:00 (CST-6)
Location: APLINGTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 4 inch diameter tree limbs down along with numerous other smaller branches in Aplington.

Thunderstorm Wind in MADISON, IOWA
From 17-MAY-17 15:02:00 to 17-MAY-17 15:02:00 (CST-6)
Location: BEVINGTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported winds estimated 50 to 60 mph.

Thunderstorm Wind in MARION, IOWA
From 17-MAY-17 15:36:00 to 17-MAY-17 15:36:00 (CST-6)
Location: PLEASANTVILLE
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported 60 mph wind gusts at Highway 5 and Highway 92.

Hail in POLK, IOWA
From 17-MAY-17 14:18:00 to 17-MAY-17 14:18:00 (CST-6)
Location: HERROLD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

NWS office in Johnston experienced quarter sized hail and wind gusts estimated around 40 to 50 mph.

Hail in MONROE, IOWA
From 17-MAY-17 15:29:00 to 17-MAY-17 15:29:00 (CST-6)
Location: ALBIA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Fire Chief reported quarter sized hail in Albia.

Thunderstorm Wind in BOONE, IOWA
From 17-MAY-17 15:25:00 to 17-MAY-17 15:50:00 (CST-6)
Location: NAPIER
Magnitude: 60.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported multiple farmsteads with roofs blown off, damage to several outbuildings, a garage blown off the foundation, and power lines down. The roof and upper levels of an old corn crib were blown off, windows broken from debris blowing into the window, a garage door was ripped off the track, 6 inch diameter tree limbs were down, large trees were down blocking a road. Another large tree limb landed on a van and porch roof destroying the van and roof.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:13:00 to 17-MAY-17 16:13:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

RWIS on US 30 recorded at 59 mph wind gust.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:12:00 to 17-MAY-17 16:20:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree on a large propane tank near Liscomb on Oaks Ave, many trees and power lines down in Marshalltown, traffic lights down in Marshalltown, and a barn down.

Thunderstorm Wind in MARION, IOWA
From 17-MAY-17 15:51:00 to 17-MAY-17 15:51:00 (CST-6)
Location: PELLA
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

RWIS station on IA 163 recorded 65 mph wind gust.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:12:00 to 17-MAY-17 15:12:00 (CST-6)
Location: SHULER MINE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee reported wind gusts of 60 mph.  Sturdy lawn chairs blownn across the lawn as well.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:43:00 to 17-MAY-17 16:43:00 (CST-6)
Location: APLINGTON
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio reported several power poles/power lines down between Parkersburg and Aplington on Highway 57.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:45:00 to 17-MAY-17 16:53:00 (CST-6)
Location: PARKERSBURG
Magnitude: 65.00 EG
Property damage: 60.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported very high winds estimated at over 70 mph.  Power reported out in Parkersburg, semi overturned on Highway 57 resulting in one fatality, and numerous tree limbs down on roads.  A 3 foot diameter tree also downed in Parkersburg.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:40:00 to 17-MAY-17 17:00:00 (CST-6)
Location: APLINGTON
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A machine shed was blown down on top of a person, who was extricated and taken to the hospital. A building in Greene collapsed and caused a gas leak. Widespread tree damage and numerous trees down, power lines down and building damage throughout the western half of the county.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:22:00 to 17-MAY-17 15:22:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported tree damage on Easton Blvd near 22nd St. Time estimated by radar.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-MAY-17 16:53:00 to 17-MAY-17 16:53:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo Airport ASOS recorded 70 mph wind gust.

Thunderstorm Wind in MARSHALL, IOWA
From 17-MAY-17 16:12:00 to 17-MAY-17 16:12:00 (CST-6)
Location: MARSHALLTOWN ARPT
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Marshalltown airport ASOS recorded a 69 mph wind gust.

Thunderstorm Wind in ADAIR, IOWA
From 17-MAY-17 14:40:00 to 17-MAY-17 14:40:00 (CST-6)
Location: ADAIR
Magnitude: 56.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A semi roll-over occurred on I-80 east of Adair due to strong winds.

Hail in DALLAS, IOWA
From 17-MAY-17 14:03:00 to 17-MAY-17 14:03:00 (CST-6)
Location: HADDEN HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail one half mile west of Jordan Creek Mall.

Thunderstorm Wind in ADAIR, IOWA
From 17-MAY-17 14:55:00 to 17-MAY-17 14:55:00 (CST-6)
Location: HOWE
Magnitude: 60.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported numerous instances across Guthrie County to the Adair County line of wind damage.  This included 2 modular offices blown off I-80 2 miles east of Stuart.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:00:00 to 17-MAY-17 15:00:00 (CST-6)
Location: LINDEN
Magnitude: 56.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported semi blown over into the ditch at the intersection of P46 and Highway 44.

Thunderstorm Wind in GUTHRIE, IOWA
From 17-MAY-17 14:50:00 to 17-MAY-17 15:20:00 (CST-6)
Location: STUART
Magnitude: 64.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported numerous instances across Guthrie County to the Adair County line of wind damage.  This included 40x60 machine shed roof taken off 4 miles SW of Panora, power lines down in Jamaica from blown over tree, power lines down in Stuart due to tree damage.

Thunderstorm Wind in CLARKE, IOWA
From 17-MAY-17 14:43:00 to 17-MAY-17 14:43:00 (CST-6)
Location: MURRAY
Magnitude: 61.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager stated home owner just west of Murray reported shingles blown off, flag pole snapped, and small tree branches down.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:10:00 to 17-MAY-17 15:25:00 (CST-6)
Location: DAWSON
Magnitude: 60.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported power poles blown down on Highway 44, semi truck blownn over at intersection of P46 and Highway 141.  All between Perry and Dawson.

Thunderstorm Wind in DALLAS, IOWA
From 17-MAY-17 15:12:00 to 17-MAY-17 15:12:00 (CST-6)
Location: HADDEN HILL
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee reported upwards of 65 mph wind gusts at home location.

Thunderstorm Wind in WARREN, IOWA
From 17-MAY-17 15:15:00 to 17-MAY-17 15:15:00 (CST-6)
Location: INDIANOLA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported numerous tree branches of 3 inch diameter and greater down.  Still have rain and some gusts to 50 to 60 mph. Time estimated by radar.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:15:00 to 17-MAY-17 15:15:00 (CST-6)
Location: CLOVER HILLS
Magnitude: 54.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee recorded 62 mph wind gust on home weather station.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:14:00 to 17-MAY-17 15:14:00 (CST-6)
Location: ASHAWA
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported multiple trees and power lines down in West Des Moines along Ashworth Rd.

Thunderstorm Wind in MADISON, IOWA
From 17-MAY-17 15:10:00 to 17-MAY-17 15:10:00 (CST-6)
Location: EARLHAM
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported tree trunks snapped.

Thunderstorm Wind in POLK, IOWA
From 17-MAY-17 15:18:00 to 17-MAY-17 15:18:00 (CST-6)
Location: LOVINGTON
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 12 to 13 inch diameter tree snapped with branches in the street.  Time estimated by radar.

Thunderstorm Wind in BUTLER, IOWA
From 17-MAY-17 16:43:00 to 17-MAY-17 16:43:00 (CST-6)
Location: KESLEY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported wind gusts to 60 mph.