A lingering frontal boundary that initiated storms the previous couple of days remained across northwest and northern Iowa on the 16th.  During the afternoon, in an environment of 1000-2000 J/kg MLCAPE and 40-50 kts effective bulk shear, storms once again initiated and propagated eastward.  Initially, storms went up in northwest Iowa and produced near-severe hail and periods of heavy rain.  During the evening, storms that initiated back in eastern Nebraska propagated across central and southern Iowa producing primarily heavy rainfall and periods of severe wind gusts and related wind damage along with one tornado. The heaviest rainfall was over southern Iowa where as much as 2+ inches of rain fell.

Hail in CALHOUN, IOWA
From 16-JUN-17 18:22:00 to 16-JUN-17 18:22:00 (CST-6)
Location: POMEROY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported hail increasing in size to quarters.

Hail in CALHOUN, IOWA
From 16-JUN-17 18:17:00 to 16-JUN-17 18:17:00 (CST-6)
Location: POMEROY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel to penny sized hail.

Hail in WEBSTER, IOWA
From 16-JUN-17 19:10:00 to 16-JUN-17 19:10:00 (CST-6)
Location: OTHO
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.  This is a delayed report.

Thunderstorm Wind in CASS, IOWA
From 16-JUN-17 19:55:00 to 16-JUN-17 19:55:00 (CST-6)
Location: LEWIS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported broken tree branches and power outages.

Thunderstorm Wind in CASS, IOWA
From 16-JUN-17 20:01:00 to 16-JUN-17 20:01:00 (CST-6)
Location: GRISWOLD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported gusts up to and around 60 mph.

Thunderstorm Wind in ADAMS, IOWA
From 16-JUN-17 20:36:00 to 16-JUN-17 20:36:00 (CST-6)
Location: CORNING
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager relayed reports of non-specific building damage near the Adams and Taylor county line.  Also reported numerous trees down around the county.  Damage was most extensive in the southern portion of the county.

Hail in STORY, IOWA
From 16-JUN-17 20:50:00 to 16-JUN-17 20:50:00 (CST-6)
Location: ZEARING
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported quarter sized hail.  This is a delayed report and time estimated from radar.

Thunderstorm Wind in CASS, IOWA
From 16-JUN-17 19:50:00 to 16-JUN-17 19:50:00 (CST-6)
Location: GRISWOLD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported broken tree branches across down along with power outages.

Thunderstorm Wind in STORY, IOWA
From 16-JUN-17 20:17:00 to 16-JUN-17 20:17:00 (CST-6)
Location: ROLAND
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Storm chaser reported lots of large tree limbs down, some large trees downed in town, a tree on a house, and power lines downed.  This is a delayed report and via social media.

Thunderstorm Wind in TAYLOR, IOWA
From 16-JUN-17 20:42:00 to 16-JUN-17 20:42:00 (CST-6)
Location: NEW MARKET
Magnitude: 61.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Three unsecured camper trailers were blown from their camp site into the lake.  One minor injury reported.

Heavy Rain in ADAMS, IOWA
From 16-JUN-17 18:30:00 to 16-JUN-17 21:15:00 (CST-6)
Location: CORNING
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.38 inches.

Thunderstorm Wind in STORY, IOWA
From 16-JUN-17 20:50:00 to 16-JUN-17 20:50:00 (CST-6)
Location: ZEARING
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported estimated wind gusts to 60 mph or more.  This is a delayed report and time estimated from radar.

Thunderstorm Wind in MARSHALL, IOWA
From 16-JUN-17 21:15:00 to 16-JUN-17 21:15:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported 60 mph wind gusts at the Iowa Veterans Home.

Heavy Rain in POWESHIEK, IOWA
From 16-JUN-17 20:00:00 to 16-JUN-17 23:45:00 (CST-6)
Location: GRINNELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.10 inches.

Heavy Rain in DECATUR, IOWA
From 16-JUN-17 19:00:00 to 17-JUN-17 00:00:00 (CST-6)
Location: LAMONI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 1.90 inches.

Heavy Rain in TAYLOR, IOWA
From 16-JUN-17 18:30:00 to 16-JUN-17 22:00:00 (CST-6)
Location: BEDFORD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.15 inches.

Thunderstorm Wind in ADAMS, IOWA
From 16-JUN-17 20:36:00 to 16-JUN-17 20:36:00 (CST-6)
Location: CORNING
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree limbs and power lines down.

Tornado in TAYLOR, IOWA
From 16-JUN-17 20:35:00 to 16-JUN-17 20:37:00 (CST-6)
Location: NEW MARKET
Tornado F-scale: EF1
Property damage: 30.00K
Crop damage: 3.00K
Reported by: NWS Storm Survey

Short tornado embedded within a large area of strong winds.  Tornado tracked southeast through a cornfield before encountering a farmstead.  It snapped and blew over trees in a grove just northwest of the farm which is where the EF1 damage occurred.  It proceeded to destroy a hoop building on the farm and blew two empty grain bins off their foundations.  Other tree damage occurred as well.  The tornado then produced some tree damage in a grove of trees along Highway 2 before dissipating.

Hail in WINNEBAGO, IOWA
From 16-JUN-17 15:36:00 to 16-JUN-17 15:36:00 (CST-6)
Location: THOMPSON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.