An unorganized area of low pressure was situated across areas of Nebraska and Iowa, with boundaries draped north and west of the state, early on the 15th. Throughout the day northwest winds transitioned the relatively stationary boundaries into cold fronts which entered northwest Iowa by early afternoon. Temperatures ahead of the front were modest in the 70s with dew points around 60. Resulting MUCAPE values ran from around 1000 J/kg in areas across northern Iowa to 2000+ J/kg across parts of southwest Iowa. Effective bulk wind shear were also borderline supportive for rotating storms in the 30 to 40kt range. The primary results of severe weather for this event were hail and heavy rainfall.

Hail in WARREN, IOWA
From 15-APR-17 18:10:00 to 15-APR-17 18:10:00 (CST-6)
Location: COOL
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported up to golf ball sized hail.  The is a delayed report.

Hail in WARREN, IOWA
From 15-APR-17 18:10:00 to 15-APR-17 18:10:00 (CST-6)
Location: COOL
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar sized hail.

Hail in TAMA, IOWA
From 15-APR-17 18:10:00 to 15-APR-17 18:10:00 (CST-6)
Location: BUCKINGHAM
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Media reported hail up to golf ball in size.  Time estimated from radar.

Hail in BLACK HAWK, IOWA
From 15-APR-17 18:15:00 to 15-APR-17 18:15:00 (CST-6)
Location: EAGLE CENTER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Media relayed reports of quarter sized hail from social media. Time estimated.

Hail in CLARKE, IOWA
From 15-APR-17 18:18:00 to 15-APR-17 18:18:00 (CST-6)
Location: WOODBURN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail covering her yard just south of Woodburn.

Hail in BLACK HAWK, IOWA
From 15-APR-17 18:25:00 to 15-APR-17 18:25:00 (CST-6)
Location: WASHBURN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in WARREN, IOWA
From 15-APR-17 18:26:00 to 15-APR-17 18:26:00 (CST-6)
Location: MILO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported quarter sized hail in the town of Milo.

Hail in WARREN, IOWA
From 15-APR-17 18:30:00 to 15-APR-17 18:30:00 (CST-6)
Location: MILO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported quarter sized hail via social media.

Hail in BLACK HAWK, IOWA
From 15-APR-17 18:31:00 to 15-APR-17 18:31:00 (CST-6)
Location: GILBERTVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Hail in POWESHIEK, IOWA
From 15-APR-17 18:36:00 to 15-APR-17 18:36:00 (CST-6)
Location: GRINNELL ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported up to quarter sized hail.

Hail in ADAIR, IOWA
From 15-APR-17 18:40:00 to 15-APR-17 18:40:00 (CST-6)
Location: ROSSERDALE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to quarter size hail along I-80 at mile marker 86 near Menlo.

Hail in MARION, IOWA
From 15-APR-17 18:54:00 to 15-APR-17 18:54:00 (CST-6)
Location: BEWBERN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to quarter sized hail on the north side of Melcher-Dallas.

Hail in GUTHRIE, IOWA
From 15-APR-17 18:55:00 to 15-APR-17 18:55:00 (CST-6)
Location: STUART
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported penny sized hail.

Hail in POWESHIEK, IOWA
From 15-APR-17 19:00:00 to 15-APR-17 19:00:00 (CST-6)
Location: MALCOLM
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to quarter sized hail.  Time estimated from radar.

Hail in MAHASKA, IOWA
From 15-APR-17 19:08:00 to 15-APR-17 19:08:00 (CST-6)
Location: NEW SHARON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail at his son's property. Time radar estimated.

Hail in JASPER, IOWA
From 15-APR-17 21:00:00 to 15-APR-17 21:00:00 (CST-6)
Location: PRAIRIE CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported pea to quarter sized hail ongoing at the time of report.

Hail in MARION, IOWA
From 15-APR-17 21:48:00 to 15-APR-17 21:48:00 (CST-6)
Location: PELLA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported up to ping pong ball sized hail.

Hail in MARION, IOWA
From 15-APR-17 23:05:00 to 15-APR-17 23:05:00 (CST-6)
Location: PELLA MUNI ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.  Time estimated from radar.

Hail in MARION, IOWA
From 15-APR-17 23:08:00 to 15-APR-17 23:08:00 (CST-6)
Location: PELLA MUNI ARPT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported up to half dollar sized hail.

Heavy Rain in WAPELLO, IOWA
From 15-APR-17 05:45:00 to 16-APR-17 05:45:00 (CST-6)
Location: DAHLONEGA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.47 inches of rain in the past 24 hours.  Delayed report.

Heavy Rain in POLK, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: ORALABOR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.14 inches over the past 24 hours and 1.97 inches over the past 48 hours.

Heavy Rain in HARDIN, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: ELDORA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.00 inches of rain in the past 24 hours and 1.34 inches in the past 48 hours.

Heavy Rain in DALLAS, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: DALLAS CENTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.05 inches of rain in the past 24 hours and 1.78 inches over the past 48 hours.

Heavy Rain in WARREN, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: SPRING HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.6 inches of rain in the past 24 hours and 1.82 inches in the past 48 hours.

Heavy Rain in DALLAS, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: HADDEN HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.07 inches of rain in the last 24 hours and 1.82 inches in the last 49 hours.

Heavy Rain in WARREN, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: SPRING HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.60 inches of rainfall in the past 24 hours.

Heavy Rain in POLK, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: POLK CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Official NWS observation of 1.24 inches of rain over the past 24 hours and 2.08 inches over the past 48 hours.

Heavy Rain in TAMA, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: TRAER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop report of 1.35 inches over the past 24 hours and 1.70 inches over the past 48 hours.

Heavy Rain in CALHOUN, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: ROCKWELL CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer report of 1.22 inches of rain over the past 24 hours and 1.91 inches over the past 48 hours.

Heavy Rain in TAMA, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: DYSART
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.28 inches of rain over the past 24 hours.

Heavy Rain in WARREN, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: INDIANOLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer report of 2.33 inches of rain over the past 24 hours and 2.41 inches over the past 48 hours.

Heavy Rain in MARSHALL, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: MARSHALLTOWN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported 1.17 inches of rain over the past 24 hours and 1.57 inches over the past 48.

Hail in WARREN, IOWA
From 15-APR-17 18:20:00 to 15-APR-17 18:20:00 (CST-6)
Location: MILO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported quarter sized hail at 180th and Tripoli.

Heavy Rain in TAMA, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: CLUTIER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported 1.58 inches of rain over the past 24 hours and 1.86 inches over the past 48 hours.

Heavy Rain in LUCAS, IOWA
From 15-APR-17 06:00:00 to 16-APR-17 06:00:00 (CST-6)
Location: CHARITON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported rainfall of 1.60 inches over the past 24 hours.

Heavy Rain in WARREN, IOWA
From 15-APR-17 07:00:00 to 16-APR-17 07:00:00 (CST-6)
Location: HARTFORD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer reported 1.46 inches of rainfall over the past 24 hours.

Heavy Rain in POLK, IOWA
From 15-APR-17 09:30:00 to 16-APR-17 09:30:00 (CST-6)
Location: (DSM)DES MOINES INTL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS report of 1.01 inches of rainfall over the past 24 hours and 1.67 inches over the past 48 hours.

Hail in POCAHONTAS, IOWA
From 15-APR-17 16:26:00 to 15-APR-17 16:26:00 (CST-6)
Location: FONDA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported hail just smaller than golf balls.

Hail in CLARKE, IOWA
From 15-APR-17 17:37:00 to 15-APR-17 17:37:00 (CST-6)
Location: OSCEOLA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail lasted for about 2 to 3 minutes with a mixture of sizes from pea to nickels.

Heavy Rain in MARION, IOWA
From 15-APR-17 17:00:00 to 16-APR-17 07:30:00 (CST-6)
Location: KNOXVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 1.40 inches of rain since 6 pm the day before.  This is a delayed report.

Hail in TAMA, IOWA
From 15-APR-17 18:12:00 to 15-APR-17 18:12:00 (CST-6)
Location: BUCKINGHAM
Magnitude: 1.50 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported their truck sustained hail damage from hail just under golf ball size just south of the Black Hawk and Tama county lines on S Ave.  Time estimated from radar.

Hail in WARREN, IOWA
From 15-APR-17 18:13:00 to 15-APR-17 18:13:00 (CST-6)
Location: COOL
Magnitude: 2.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Social Media

Media relayed via social media public reports of hail just under baseball in size.  Time estimated from radar.

Hail in LUCAS, IOWA
From 15-APR-17 18:54:00 to 15-APR-17 18:54:00 (CST-6)
Location: OAKLEY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported half dollar sized hail. Image relayed by WHOTV via social media.

Hail in TAMA, IOWA
From 15-APR-17 18:16:00 to 15-APR-17 18:22:00 (CST-6)
Location: TRAER MUNI ARPT
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported a wide swath of ping pong ball sized hail from Traer to Hickory Hollow Park.  Time estimated from radar.

Hail in BLACK HAWK, IOWA
From 15-APR-17 18:18:00 to 15-APR-17 18:18:00 (CST-6)
Location: LA PORTE CITY ARPT
Magnitude: 2.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Media relayed reports of broken windshields from nearly baseball sized hail.  Time estimated from radar.

Hail in DALLAS, IOWA
From 15-APR-17 20:27:00 to 15-APR-17 20:27:00 (CST-6)
Location: HADDEN HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported dime to quarter sized hail at Mills Civic Parkway and Stagecoach Drive.

Hail in CALHOUN, IOWA
From 15-APR-17 15:46:00 to 15-APR-17 15:46:00 (CST-6)
Location: YETTER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to quarter size hail covering the ground along with winds to around 50 mph.

Hail in CALHOUN, IOWA
From 15-APR-17 16:00:00 to 15-APR-17 16:00:00 (CST-6)
Location: SHERWOOD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Hail in STORY, IOWA
From 15-APR-17 16:24:00 to 15-APR-17 16:24:00 (CST-6)
Location: STORY CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported penny sized hail.

Thunderstorm Wind in HARDIN, IOWA
From 15-APR-17 17:02:00 to 15-APR-17 17:02:00 (CST-6)
Location: NEW PROVIDENCE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported 60 mph wind gusts.

Hail in HARDIN, IOWA
From 15-APR-17 17:12:00 to 15-APR-17 17:12:00 (CST-6)
Location: ELDORA MUNI ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in GRUNDY, IOWA
From 15-APR-17 17:25:00 to 15-APR-17 17:25:00 (CST-6)
Location: IVESTER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported lots of dime to quarter sized hail along Highway 175 just east of the Hardin-Grundy county line.

Hail in MARION, IOWA
From 15-APR-17 17:37:00 to 15-APR-17 17:37:00 (CST-6)
Location: FLAGLER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported penny sized hail.

Hail in CLARKE, IOWA
From 15-APR-17 17:42:00 to 15-APR-17 17:42:00 (CST-6)
Location: OSCEOLA MUNI ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to quarter sized hail.

Hail in TAMA, IOWA
From 15-APR-17 17:51:00 to 15-APR-17 17:51:00 (CST-6)
Location: LINCOLN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported quarter sized hail via social media.  Time estimated from radar.

Hail in WARREN, IOWA
From 15-APR-17 17:56:00 to 15-APR-17 17:56:00 (CST-6)
Location: NEW VIRGINIA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported penny sized hail.

Hail in TAMA, IOWA
From 15-APR-17 17:58:00 to 15-APR-17 17:58:00 (CST-6)
Location: LINCOLN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported quarter sized hail along with estimated winds of 40 to 50 mph.