The state was stuck under northwest flow aloft, resulting in shortwaves aloft initiating storms.  Additionally, at the surface a warm frontal boundary resided across the southwest third to half of the state during the day of the 21st and through the overnight.  Some storms initially developed during the afternoon and evening hours in the immediate vicinity of the front in southern and central Iowa and produced periods of heavy rainfall.  Storms primarily resulted in heavy rainfall and a couple of severe wind reports.  The primary action initiated late in the evening across the northwest third of the state, in the vicinity of the warm front as it moved northward.  Given northwest steering flow and a nearly station surface front, storms trained through the evening and resulted in rainfall totals as high as 3.71 inches.

Heavy Rain in GRUNDY, IOWA
From 21-JUN-16 08:00:00 to 22-JUN-16 08:00:00 (CST-6)
Location: DIKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station recorded heavy rainfall of 3.04 inches over the last 24 hours.

Flash Flood in BLACK HAWK, IOWA
From 22-JUN-16 07:31:00 to 22-JUN-16 07:31:00 (CST-6)
Location: WATERLOO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported portions of University Ave from Cedar Falls to Waterloo impassable.

Heavy Rain in GUTHRIE, IOWA
From 21-JUN-16 08:15:00 to 22-JUN-16 08:15:00 (CST-6)
Location: MONTEITH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Panora recorded heavy rainfall of 2.20 inches over the last 24 hours.

Heavy Rain in TAMA, IOWA
From 21-JUN-16 21:25:00 to 22-JUN-16 08:30:00 (CST-6)
Location: TRAER MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 3.50 inches.  Beginning time radar estimated.

Heavy Rain in WORTH, IOWA
From 21-JUN-16 08:45:00 to 22-JUN-16 08:45:00 (CST-6)
Location: FERTILE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Fertile recorded heavy rainfall of 2.44 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 08:42:00 to 22-JUN-16 08:42:00 (CST-6)
Location: CEDAR FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Cedar Falls recorded heavy rainfall of 2.56 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 23:00:00 to 22-JUN-16 09:00:00 (CST-6)
Location: WATERLOO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 3.71 inches.  Report via social media.  Beginning time radar estimated.

Hail in WAYNE, IOWA
From 21-JUN-16 19:00:00 to 21-JUN-16 19:00:00 (CST-6)
Location: HUMESTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Report via social media.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 08:48:00 to 22-JUN-16 08:48:00 (CST-6)
Location: CEDAR FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Cedar Falls recorded heavy rainfall of 2.84 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 08:46:00 to 22-JUN-16 08:46:00 (CST-6)
Location: CEDAR FALLS JCT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Waterloo recorded heavy rainfall of 2.48 inches over the last 24 hours.

Heavy Rain in WORTH, IOWA
From 21-JUN-16 08:49:00 to 22-JUN-16 08:49:00 (CST-6)
Location: FERTILE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in Fertile reported heavy rainfall of 2.65 inches over the last 24 hours.

Flash Flood in BUTLER, IOWA
From 22-JUN-16 01:30:00 to 22-JUN-16 01:30:00 (CST-6)
Location: GREENE
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported several gravel roads throughout Butler County had water flowing over them, plus a blacktop, C13 outside of Greene, had deep water flowing over it.  Time estimated by the Emergency Manager, between 2-3 am.

Thunderstorm Wind in WEBSTER, IOWA
From 22-JUN-16 02:08:00 to 22-JUN-16 02:08:00 (CST-6)
Location: FT DODGE
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported a large tree branch downed onto a law enforcement vehicle.

Lightning in BUTLER, IOWA
From 22-JUN-16 02:15:00 to 22-JUN-16 02:15:00 (CST-6)
Location: GREENE
Property damage: 150.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported a house fire due to a lightning strike.

Heavy Rain in APPANOOSE, IOWA
From 21-JUN-16 19:30:00 to 21-JUN-16 21:40:00 (CST-6)
Location: CENTERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 1.10 inches.  Heavies rain fell between 2129 and 2140 CDT.

Hail in APPANOOSE, IOWA
From 21-JUN-16 21:19:00 to 21-JUN-16 21:19:00 (CST-6)
Location: CENTERVILLE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny to nickel hail was reported.

Thunderstorm Wind in KOSSUTH, IOWA
From 22-JUN-16 01:12:00 to 22-JUN-16 01:12:00 (CST-6)
Location: ALGONA MUNI ARPT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Algona airport AWOS measured wind gust of 59 mph.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 04:00:00 to 22-JUN-16 04:00:00 (CST-6)
Location: CASTLE HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer 2 SE Waterloo Regional Airport reported heavy rainfall of 2.73 inches over the last 24 hours.

Heavy Rain in CERRO GORDO, IOWA
From 21-JUN-16 05:53:00 to 22-JUN-16 05:53:00 (CST-6)
Location: (MCW)MASON CITY MUNI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mason City ASOS station recorded heavy rainfall of 2.10 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 06:00:00 to 22-JUN-16 06:00:00 (CST-6)
Location: CEDAR FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer reported heavy rainfall of 2.36 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 05:54:00 to 22-JUN-16 05:54:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo airport ASOS station recorded heavy rainfall of 2.42 inches over the last 24 hours.

Heavy Rain in TAMA, IOWA
From 21-JUN-16 06:00:00 to 22-JUN-16 06:00:00 (CST-6)
Location: TRAER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported heavy rainfall of 2.25 inches over the last 24 hours.

Heavy Rain in CERRO GORDO, IOWA
From 21-JUN-16 06:45:00 to 22-JUN-16 06:45:00 (CST-6)
Location: MASON CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.48 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 23:00:00 to 22-JUN-16 04:00:00 (CST-6)
Location: HUDSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported storm total heavy rainfall of 3.20 inches from midnight to 5 am.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-16 23:00:00 to 22-JUN-16 07:00:00 (CST-6)
Location: NORTH CEDAR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 3.25 inches between midnight and 8am.  Reported via social media.

Hail in WINNEBAGO, IOWA
From 21-JUN-16 22:30:00 to 21-JUN-16 22:50:00 (CST-6)
Location: FOREST CITY
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail was reported lasting a long time, and then heavy rain after.