An ideal setup was seen across northern and central Iowa for repeated rounds of heavy rainfall and severe weather.  A weak warm frontal boundary stalled out across the area as it transitioned to a stationary boundary and allowed multiple rounds of storms to initiate on the 21st and well into the 22nd.  Primarily heavy rainfall and flooding was seen, however a couple of hail and a handful of damaging wind reports were received as well.  The hardest hit areas were from roughly Forest City on southeast towards Mason city and Waverly. Rainfall amounts of 4 to 6 plus inches were seen, with greatest amounts just outside of the Des Moines county warning area in and around Charles City.

Flood in BREMER, IOWA
From 22-SEP-16 05:30:00 to 23-SEP-16 10:00:00 (CST-6)
Location: PLAINFIELD
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported street flooding along 130th in Plainfield, along with several other roads in the Plainfield area.

Heavy Rain in CERRO GORDO, IOWA
From 21-SEP-16 05:53:00 to 22-SEP-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 recorded heavy rainfall of 2.53 inches over the last 24 hours.

Heavy Rain in HANCOCK, IOWA
From 21-SEP-16 05:55:00 to 22-SEP-16 05:55:00 (CST-6)
Location: MILLER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Forest City AWOS recorded heavy rainfall of 2.19 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.3 inches over the last 24 hours.

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

Coop observer KIOW Radio recorded heavy rainfall of 3.05 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.1 inches over the last 24 hours.

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

Mason City ASOS recorded heavy rainfall of 2.53 inches over the last 24 hours.

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

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

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

Coop observer recorded heavy rainfall of 4.13 inches over the last 24 hours.

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

Public reported heavy rainfall of 2.88 inches over the last 24 hours.

Heavy Rain in CERRO GORDO, IOWA
From 21-SEP-16 06:00:00 to 22-SEP-16 06:00:00 (CST-6)
Location: CLEAR LAKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 4.00 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.26 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.35 inches over the last 24 hours.

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

Coop observer KIMT TV recorded heavy rainfall of 2.38 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 4.13 inches over the last 24 hours.

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

CoCoRaHS observer in Swaledale recorded heavy rainfall of 2.4 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.1 inches over the last 24 hours.

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

CoCoRaHS observer recorded heavy rainfall of 2.61 inches over the last 24 hours.

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

Coop observer recorded heavy rainfall of 2.30 inches over the last 24 hours.

Heavy Rain in BUTLER, IOWA
From 21-SEP-16 07:00:00 to 22-SEP-16 07:00:00 (CST-6)
Location: CLARKSVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.30 inches over the last 24 hours.

Heavy Rain in CERRO GORDO, IOWA
From 21-SEP-16 09:00:00 to 22-SEP-16 09:00:00 (CST-6)
Location: CLEAR LAKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station recorded heavy rainfall of 2.27 inches over the last 24 hours.

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

Mesonet station recorded heavy rainfall of 2.10 inches over the last 24 hours.

Heavy Rain in GRUNDY, IOWA
From 21-SEP-16 09:00:00 to 22-SEP-16 09:00:00 (CST-6)
Location: DIKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station recorded heavy rainfall of 2.37 inches over the last 24 hours.

Heavy Rain in WRIGHT, IOWA
From 21-SEP-16 09:00:00 to 22-SEP-16 09:00:00 (CST-6)
Location: SOLBERG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station recorded heavy rainfall of 2.15 inches over the last 24 hours.

Heavy Rain in CERRO GORDO, IOWA
From 21-SEP-16 09:30:00 to 22-SEP-16 09:30:00 (CST-6)
Location: MASON CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station recorded heavy rainfall of 4.21 inches over the last 24 hours.

Heavy Rain in WORTH, IOWA
From 21-SEP-16 15:30:00 to 22-SEP-16 09:30:00 (CST-6)
Location: DEER CREEK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 6.25 inches from yesterday evening through this morning.

Flash Flood in CERRO GORDO, IOWA
From 21-SEP-16 17:30:00 to 21-SEP-16 23:25:00 (CST-6)
Location: FREEMAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported creek in pasture out of banks and rising.  Location estimated.

Heavy Rain in WINNEBAGO, IOWA
From 21-SEP-16 13:30:00 to 22-SEP-16 08:30:00 (CST-6)
Location: LELAND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported storm total heavy rainfall of 3.03 inches.

Heavy Rain in BUTLER, IOWA
From 21-SEP-16 15:00:00 to 22-SEP-16 17:00:00 (CST-6)
Location: GREENE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Greene fire department reported a storm total rainfall since beginning Wednesday of 10.40 inches.  Total rainfall since last report, 7.5 inches through 10:47pm previous night, was 2.9 inches. Relayed by Butler County Emergency Manager.

Heavy Rain in BUTLER, IOWA
From 21-SEP-16 05:00:00 to 22-SEP-16 17:00:00 (CST-6)
Location: PARKERSBURG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 3.15 inches, over a duration of 36 hours.

Hail in CERRO GORDO, IOWA
From 21-SEP-16 14:32:00 to 21-SEP-16 14:32:00 (CST-6)
Location: CARTERSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Flood in BUTLER, IOWA
From 22-SEP-16 07:26:00 to 23-SEP-16 10:00:00 (CST-6)
Location: GREENE
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported most roads closed in and around Greene.  The only way to access the town is via Highway 14.  Delayed report.

Flood in BREMER, IOWA
From 22-SEP-16 13:24:00 to 23-SEP-16 10:00:00 (CST-6)
Location: FREDERIKA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported US Highway 63 closed to southbound traffic due to flooding.  Detour in place.

Flood in BUTLER, IOWA
From 22-SEP-16 13:25:00 to 23-SEP-16 10:00:00 (CST-6)
Location: CLARKSVILLE
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported Highway 188 closed in both directions due to flooding.  Detour in place.

Thunderstorm Wind in CERRO GORDO, IOWA
From 21-SEP-16 14:55:00 to 21-SEP-16 14:55:00 (CST-6)
Location: HANFORD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 3 inch tree branches down along with quarter sized hail.

Hail in CERRO GORDO, IOWA
From 21-SEP-16 16:50:00 to 21-SEP-16 17:00:00 (CST-6)
Location: ROCK FALLS
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported hail lasted for around 10 minutes, starting out as pea sized and gradually got bigger to around half dollar size.

Thunderstorm Wind in CERRO GORDO, IOWA
From 21-SEP-16 16:50:00 to 21-SEP-16 16:50:00 (CST-6)
Location: MASON CITY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported tree limbs approximately 3 inches in diameter down.

Flood in BUTLER, IOWA
From 22-SEP-16 21:10:00 to 23-SEP-16 10:00:00 (CST-6)
Location: CLARKSVILLE
Flood cause: Dam / Levee Break
Property damage: 300.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported levee on the west side of Clarksville along the Shell Rock river failed and the southwest side of town is flooding.  Residents being evacuated.

Thunderstorm Wind in CERRO GORDO, IOWA
From 21-SEP-16 17:17:00 to 21-SEP-16 17:17:00 (CST-6)
Location: PORTLAND
Magnitude: 56.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported a large tree downed, estimated 1 foot or more in diameter.

Thunderstorm Wind in BUTLER, IOWA
From 21-SEP-16 17:38:00 to 21-SEP-16 17:38:00 (CST-6)
Location: GREENE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Observed tree damage in storm chaser live video stream.  Multiple large tree limbs down.

Thunderstorm Wind in BUTLER, IOWA
From 21-SEP-16 17:40:00 to 21-SEP-16 17:40:00 (CST-6)
Location: GREENE
Magnitude: 56.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported trees down on roofs and power lines.  Extent of damage unknown at the time.  Time estimated from radar.

Hail in CERRO GORDO, IOWA
From 21-SEP-16 17:50:00 to 21-SEP-16 17:50:00 (CST-6)
Location: MASON CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported penny sized hail.

Thunderstorm Wind in BUTLER, IOWA
From 21-SEP-16 17:45:00 to 21-SEP-16 17:45:00 (CST-6)
Location: GREENE
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported widespread tree damage throughout town, including several trees on houses.

Flash Flood in CERRO GORDO, IOWA
From 21-SEP-16 18:00:00 to 21-SEP-16 21:40:00 (CST-6)
Location: ROCKWELL
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Department of Highways

DOT reported county roads flooded near Rockwell.  Delayed report.

Hail in BUTLER, IOWA
From 21-SEP-16 18:11:00 to 21-SEP-16 18:11:00 (CST-6)
Location: GREENE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported quarter sized hail.

Hail in BUTLER, IOWA
From 21-SEP-16 18:49:00 to 21-SEP-16 18:49:00 (CST-6)
Location: GREENE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported quarter sized hail.

Flood in BUTLER, IOWA
From 22-SEP-16 12:25:00 to 23-SEP-16 10:00:00 (CST-6)
Location: CLARKSVILLE
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

Public reported water over the road on Highway 188 just south of Clarksville.

Flash Flood in CERRO GORDO, IOWA
From 21-SEP-16 19:15:00 to 21-SEP-16 23:25:00 (CST-6)
Location: MASON CITY
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Cerro Gordo County dispatch noted that East Park had been fully closed due to flooding.

Flash Flood in BUTLER, IOWA
From 21-SEP-16 21:40:00 to 22-SEP-16 06:59:00 (CST-6)
Location: GREENE
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 500.00K
Reported by: Emergency Manager

Emergency Manager reported many roads closed throughout the northern fourth of Butler county.  The Shell Rock river reported beginning to leave its banks and moving toward businesses in downtown Greene.  Sandbagging ongoing in Green and Clarksville.

Heavy Rain in BUTLER, IOWA
From 21-SEP-16 15:00:00 to 21-SEP-16 20:30:00 (CST-6)
Location: GREENE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Green fire department reported heavy rainfall of 7.50 inches storm total.

Flash Flood in BUTLER, IOWA
From 22-SEP-16 00:47:00 to 22-SEP-16 06:59:00 (CST-6)
Location: GREENE
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported multiple homes in Greene now being impacted by floodwaters from the rapidly rising Shell Rock river.  Also estimated that the river is near the level it reached in 2008.

Flash Flood in BUTLER, IOWA
From 22-SEP-16 04:00:00 to 22-SEP-16 06:59:00 (CST-6)
Location: GREENE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported evacuations occurring in Greene due to flash flooding.

Thunderstorm Wind in GRUNDY, IOWA
From 22-SEP-16 04:15:00 to 22-SEP-16 04:15:00 (CST-6)
Location: WELLSBURG
Magnitude: 52.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported damage to several large trees.  Time estimated.

Heavy Rain in HANCOCK, IOWA
From 21-SEP-16 05:00:00 to 22-SEP-16 05:00:00 (CST-6)
Location: BRITT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer in Britt recorded heavy rainfall of 2.45 inches over the last 24 hours.

Heavy Rain in WINNEBAGO, IOWA
From 21-SEP-16 05:00:00 to 22-SEP-16 05:00:00 (CST-6)
Location: LAKE MILLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer in Lake Mills recorded heavy rainfall of 2.07 inches over the last 24 hours.

Flash Flood in CERRO GORDO, IOWA
From 22-SEP-16 05:20:00 to 22-SEP-16 09:00:00 (CST-6)
Location: ROCKWELL
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 200.00K
Reported by: Law Enforcement

Law enforcement reported barricades put up due to street flooding along Highway 65 near Rockwell.