A surface low to the northwest of Iowa allowed for convection to develop in the warm sector and along the surface boundary as it pushed across northern Iowa through the afternoon and evening of the 21st. These storms caused damaging winds and large hail across northern and central Iowa. Localized areas received heavy rain that resulted in flooding overnight. Another shortwave embedded within the parent longwave trough allowed for additional rain across the state on the 22nd that lasted through the afternoon. This second round of rain exacerbated the ongoing flooded areas, resulting in flooding that lingered into the morning of the 24th.

Lightning in WORTH, IOWA
From 21-JUN-20 18:00:00 to 21-JUN-20 18:00:00 (CST-6)
Location: NORTHWOOD
Property damage: 2.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer reported that lightning hit a walnut tree 100 ft. from the house and fried the well pump.

Hail in CERRO GORDO, IOWA
From 21-JUN-20 17:54:00 to 21-JUN-20 17:54:00 (CST-6)
Location: CLEAR LAKE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report via mping of quarter sized hail.

Hail in CERRO GORDO, IOWA
From 21-JUN-20 17:55:00 to 21-JUN-20 17:55:00 (CST-6)
Location: CLEAR LAKE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report via mping of penny sized hail.

Hail in CERRO GORDO, IOWA
From 21-JUN-20 17:55:00 to 21-JUN-20 17:55:00 (CST-6)
Location: CLEAR LAKE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of nickle sized hail.

Hail in CERRO GORDO, IOWA
From 21-JUN-20 18:12:00 to 21-JUN-20 18:12:00 (CST-6)
Location: WINNEBAGO HGTS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter report of penny sized hail.

Hail in CERRO GORDO, IOWA
From 21-JUN-20 18:19:00 to 21-JUN-20 18:19:00 (CST-6)
Location: BURCHINAL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of quarter sized hail. Location estimated via radar.

Hail in BUTLER, IOWA
From 21-JUN-20 18:30:00 to 21-JUN-20 18:40:00 (CST-6)
Location: CLARKSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Fire Department reported quarter sized hail mixed with smaller hail lasting approximately ten minutes.

Hail in POLK, IOWA
From 21-JUN-20 23:44:00 to 21-JUN-20 23:44:00 (CST-6)
Location: LOVINGTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 50 mph winds and small twigs broken with nickle hail in the Beaverdale neighborhood of Des Moines.

Thunderstorm Wind in FRANKLIN, IOWA
From 21-JUN-20 18:40:00 to 21-JUN-20 18:40:00 (CST-6)
Location: HAMPTON MUNI ARPT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree limbs down west of Hampton. Time and location estimated via radar.

Thunderstorm Wind in HARDIN, IOWA
From 21-JUN-20 19:10:00 to 21-JUN-20 19:10:00 (CST-6)
Location: IOWA FALLS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported multiple tree limbs and power lines down in Iowa Falls.

Thunderstorm Wind in HARDIN, IOWA
From 21-JUN-20 19:10:00 to 21-JUN-20 19:10:00 (CST-6)
Location: IOWA FALLS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported multiple tree limbs and power lines down in Iowa Falls.

Thunderstorm Wind in BREMER, IOWA
From 21-JUN-20 19:36:00 to 21-JUN-20 19:36:00 (CST-6)
Location: PLAINFIELD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report via mping of broken tree limbs.

Thunderstorm Wind in BREMER, IOWA
From 21-JUN-20 19:36:00 to 21-JUN-20 19:36:00 (CST-6)
Location: PLAINFIELD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report via mping of broken tree limbs.

Thunderstorm Wind in POLK, IOWA
From 22-JUN-20 00:00:00 to 22-JUN-20 00:00:00 (CST-6)
Location: DES MOINES
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa department of transportation reported power lines and trees down along E 14th and Highway 69. Large tree blocking southbound lanes. Time estimated via radar.

Thunderstorm Wind in POLK, IOWA
From 22-JUN-20 00:05:00 to 22-JUN-20 00:05:00 (CST-6)
Location: DES MOINES
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of tree down on road. Time estimated via radar.

Thunderstorm Wind in POLK, IOWA
From 22-JUN-20 00:05:00 to 22-JUN-20 00:05:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of tree damage along east Douglas. Time estimated via radar.

Thunderstorm Wind in JASPER, IOWA
From 22-JUN-20 00:52:00 to 22-JUN-20 00:52:00 (CST-6)
Location: NEWTON MUNI ARPT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Jasper county dispatch relayed reports of tree damage between Newton and Reasnor. Other tree damage in eastern Jasper county. Time estimated via radar.

Thunderstorm Wind in JASPER, IOWA
From 22-JUN-20 00:58:00 to 22-JUN-20 00:58:00 (CST-6)
Location: KILLDUFF
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report that the wood frame of a steel building was blown down. They also received 2.5 inches of rain.

Thunderstorm Wind in EMMET, IOWA
From 21-JUN-20 16:20:00 to 21-JUN-20 16:20:00 (CST-6)
Location: GRUVER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager report of downed power poles and trees across town. Estimated gusts at 60 mph.

Thunderstorm Wind in CERRO GORDO, IOWA
From 21-JUN-20 17:56:00 to 21-JUN-20 17:56:00 (CST-6)
Location: (MCW)MASON CITY MUNI
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mason City ASOS recorded gust of 54 knots.

Thunderstorm Wind in CERRO GORDO, IOWA
From 21-JUN-20 18:20:00 to 21-JUN-20 18:20:00 (CST-6)
Location: BURCHINAL
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

RWIS site RMCI4 south of Mason City reported a gust of 50 knots.

Thunderstorm Wind in FRANKLIN, IOWA
From 21-JUN-20 18:45:00 to 21-JUN-20 18:45:00 (CST-6)
Location: HAMPTON
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Hampton AWOS reported a gust of 63 knots.

Thunderstorm Wind in FRANKLIN, IOWA
From 21-JUN-20 18:45:00 to 21-JUN-20 18:45:00 (CST-6)
Location: HAMPTON
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Hampton AWOS reported a gust of 63 knots.

Thunderstorm Wind in BREMER, IOWA
From 21-JUN-20 19:38:00 to 21-JUN-20 19:38:00 (CST-6)
Location: PLAINFIELD
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of 60 mph wind gust.

Thunderstorm Wind in POLK, IOWA
From 22-JUN-20 00:30:00 to 22-JUN-20 00:30:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Personal weather station AS602 recorded a gust of 52 knots.

Thunderstorm Wind in DECATUR, IOWA
From 22-JUN-20 01:02:00 to 22-JUN-20 01:02:00 (CST-6)
Location: (30I)LAMONI MUNI ARP
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Lamoni Airport ASOS reported a gust of 53 knots.

Flash Flood in BUTLER, IOWA
From 21-JUN-20 20:30:00 to 22-JUN-20 20:30:00 (CST-6)
Location: AUSTINVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported several secondary roads underwater across the county including at 260th and Douglas.

Heavy Rain in BUTLER, IOWA
From 21-JUN-20 18:24:00 to 21-JUN-20 21:24:00 (CST-6)
Location: KESLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 6 inches of rain in 3 hours.

Flood in GRUNDY, IOWA
From 22-JUN-20 01:19:00 to 24-JUN-20 09:15:00 (CST-6)
Location: REINBECK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa Department of Transportation reported 6 to 8 inches of standing water along highway 175, east of T55. This was relayed by the Grundy county sheriff.

Heavy Rain in TAMA, IOWA
From 21-JUN-20 03:30:00 to 22-JUN-20 03:30:00 (CST-6)
Location: CLUTIER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station reported a 24 hour rain total of 2.31 inches.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-20 03:54:00 to 22-JUN-20 03:54:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo ASOS reported a 24 rain total of 2.35 inches.

Flood in TAMA, IOWA
From 23-JUN-20 00:00:00 to 24-JUN-20 09:15:00 (CST-6)
Location: DYSART
Flood cause: Heavy Rain
Property damage: 400.00K
Crop damage: 0.00K
Reported by: Local Official

The public works director for La Porte City, IA reported over 75 homes impacted from the flooding with some homes reporting flooding impacts that extended to include both basements and part of the main level of the home. Flooding continued to block roads in town in areas that hadn't seen flood impacts since widespread flooding from the floods of 2008.

Heavy Rain in GRUNDY, IOWA
From 21-JUN-20 04:01:00 to 22-JUN-20 04:01:00 (CST-6)
Location: REINBECK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Personal weather station reported a 24 hour rain total of of 2.20 inches.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-20 04:02:00 to 22-JUN-20 04:02:00 (CST-6)
Location: LA PORTE CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Personal weather station reported a 24 hour rain total of 3.92 inches.

Flood in GRUNDY, IOWA
From 22-JUN-20 05:33:00 to 24-JUN-20 09:15:00 (CST-6)
Location: CONRAD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported 1.3 inches of rain with localized street flooding in the town of Conrad.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-20 07:16:00 to 22-JUN-20 07:16:00 (CST-6)
Location: CASTLE HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of 3.80 inches of rain in 24 hours.

Heavy Rain in JASPER, IOWA
From 21-JUN-20 08:19:00 to 22-JUN-20 08:19:00 (CST-6)
Location: NEWTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of 2.55 inches of rain in the last 24 hours.

Heavy Rain in TAMA, IOWA
From 21-JUN-20 10:45:00 to 22-JUN-20 10:45:00 (CST-6)
Location: CLUTIER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Personal weather station reported 24 hour storm total rainfall as of 1145 am. Still raining at time of observation.

Flash Flood in POLK, IOWA
From 22-JUN-20 11:15:00 to 22-JUN-20 11:15:00 (CST-6)
Location: WEST DES MOINES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report via social media of a vehicle stranded at 56th and Waterbury.

Heavy Rain in GRUNDY, IOWA
From 21-JUN-20 12:00:00 to 22-JUN-20 12:00:00 (CST-6)
Location: DIKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop reported 24 hour rain total of 2.52 inches. Still raining at observation.

Heavy Rain in TAMA, IOWA
From 21-JUN-20 12:02:00 to 22-JUN-20 12:02:00 (CST-6)
Location: TRAER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter has measured around 4 inches of rain in the last 24 hours with 7.75 inches measured since Friday. Reported flooding in the wolf creek area.

Heavy Rain in BLACK HAWK, IOWA
From 21-JUN-20 12:12:00 to 22-JUN-20 12:12:00 (CST-6)
Location: LA PORTE CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station reported a 24 hour rain total of 5.94 inches thus far. Still raining at time of report.

Heavy Rain in GRUNDY, IOWA
From 21-JUN-20 12:18:00 to 22-JUN-20 12:18:00 (CST-6)
Location: REINBECK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station reported a 24 hour rain total of 3.28 inches thus far. Still raining at report time.

Heavy Rain in TAMA, IOWA
From 21-JUN-20 12:30:00 to 22-JUN-20 12:30:00 (CST-6)
Location: DYSART
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station reported a 24 hour rain total of 3.43 inches. Still raining at time of report.

Heavy Rain in POLK, IOWA
From 21-JUN-20 12:40:00 to 22-JUN-20 12:40:00 (CST-6)
Location: WEST DES MOINES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mesonet reported a 24 hour rain total of 3.81 inches. Still raining at time of report.

Heavy Rain in POLK, IOWA
From 21-JUN-20 12:42:00 to 22-JUN-20 12:42:00 (CST-6)
Location: CAPITOL HGTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mesonet reported 24 rai total of 3.53 inces. Still raining at time of report.

Heavy Rain in POLK, IOWA
From 21-JUN-20 12:44:00 to 22-JUN-20 12:44:00 (CST-6)
Location: DES MOINES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mesonet reported a 24 hour rain total of 3.34 inches. Still raining at time of report.

Heavy Rain in JASPER, IOWA
From 21-JUN-20 12:46:00 to 22-JUN-20 12:46:00 (CST-6)
Location: COLFAX
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mesonet reported a 24 hour rain total of 3.68 inches. Still raining at time of report.

Heavy Rain in TAMA, IOWA
From 21-JUN-20 23:00:00 to 22-JUN-20 12:51:00 (CST-6)
Location: GARWIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of 6.31 inches of rain since midnight.

Heavy Rain in GRUNDY, IOWA
From 21-JUN-20 23:00:00 to 22-JUN-20 12:53:00 (CST-6)
Location: BEAMAN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report of 5.03 inches of rain since midnight.

Flood in TAMA, IOWA
From 22-JUN-20 23:20:00 to 24-JUN-20 09:15:00 (CST-6)
Location: TRAER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The department of transportation relayed a report from the Tama county sheriff's office that there was flooding on US 63 south from just north of Traer by the golf course near Wolf Creek. Water was over the southbound lane roughly to the centerline.

Flood in TAMA, IOWA
From 23-JUN-20 00:38:00 to 24-JUN-20 09:15:00 (CST-6)
Location: TRAER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa Department of Transportation and the Tama county sheriff confirm both lanes of US 63 are covered in water as confirmed by multiple 911 calls.

Flood in TAMA, IOWA
From 23-JUN-20 01:24:00 to 24-JUN-20 09:15:00 (CST-6)
Location: IRVING
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa Department of Transportation reports water over highway 21 north of Belle Plaine. Hard closures are in place at E66 and Highway 30.