A meandering boundary found itself draped across Iowa on the 18th and into the 19th of June, acting as a continued focusing mechanism for showers and thunderstorms.  A weakly sheared environment took away form the potential for sustained severe weather, however with as much as 3000 to 4000 J/kg MUCAPE during the afternoon and early evening, opportunities for at least brief severe storms were possible. More concerning though was the heavy rainfall potential with the near stationary boundary, surface dew points in the low to mid 70s, precipitable water values around 2.0 inches, and at least a weak low level jet continuing to initiate storms and advect in more moisture.
The day and overnight generally played out as much with brief strong to severe storms during or just after peak heating, followed by numerous rounds of showers and storms initiated along or near the boundary.  Besides the small handful of severe reports, heavy rainfall in the 2 to 4 inch range dominated, including a flooding report around Sac City.

Heavy Rain in GUTHRIE, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: JAMAICA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.58 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: FT DODGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.42 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: WATERLOO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.15 inches over the last 24 hours.

Heavy Rain in CARROLL, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: COON RAPIDS
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 BOONE, IOWA
From 18-JUN-18 15:45:00 to 19-JUN-18 06:30:00 (CST-6)
Location: MADRID
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public relayed a picture of their rain gage with about 3.1 inches of heavy rainfall since last night. Location was about 4 mi north of the High Trestle Trail Bridge.

Hail in WEBSTER, IOWA
From 18-JUN-18 14:05:00 to 18-JUN-18 14:05:00 (CST-6)
Location: CLARE
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported half dollar sized hail.

Thunderstorm Wind in WEBSTER, IOWA
From 18-JUN-18 14:05:00 to 18-JUN-18 14:05:00 (CST-6)
Location: CLARE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported medium to large branches down in their yard.

Heavy Rain in POCAHONTAS, IOWA
From 18-JUN-18 12:45:00 to 19-JUN-18 06:30:00 (CST-6)
Location: FONDA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public relayed report of heavy rainfall of 2.8 inches in Fonda over about the last 17 hours.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 15:30:00 to 18-JUN-18 20:30:00 (CST-6)
Location: MADRID
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 3.09 through 9:30 pm.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 15:30:00 to 19-JUN-18 02:50:00 (CST-6)
Location: MADRID
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported storm total heavy rainfall of 3.75 inches so far since Monday evening.

Heavy Rain in CARROLL, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: HALBUR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 3.28 inches over the last 24 hours.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 07:00:00 to 19-JUN-18 07:00:00 (CST-6)
Location: PLEASANT HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.84 inches over the last 24 hours.

Heavy Rain in POCAHONTAS, IOWA
From 18-JUN-18 07:00:00 to 19-JUN-18 07:00:00 (CST-6)
Location: VARINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.20 inches over the last 24 hours.

Heavy Rain in CARROLL, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: CARROLL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 3.75 inches over the last 24 hours.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 15:45:00 to 19-JUN-18 08:40:00 (CST-6)
Location: MADRID
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported storm total heavy rainfall of 4.24 inches.

Heavy Rain in CRAWFORD, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: DENISON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 3.3 inches over the last 24 hours.

Heavy Rain in FRANKLIN, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: HAMPTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.07 inches over the last 24 hours.

Flash Flood in SAC, IOWA
From 18-JUN-18 18:01:00 to 18-JUN-18 18:01:00 (CST-6)
Location: SAC CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported standing water at the intersection Audubon and 10th Street.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 04:38:00 to 19-JUN-18 04:38:00 (CST-6)
Location: MOINGONA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer reported heavy rainfall of 2.42 inches over the last 24 hours.

Heavy Rain in BLACK HAWK, IOWA
From 18-JUN-18 05:54:00 to 19-JUN-18 05:54:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo Municipal Airport ASOS recorded heavy rainfall of 2.17 inches over the last 24 hours.

Heavy Rain in CARROLL, IOWA
From 18-JUN-18 05:55:00 to 19-JUN-18 05:55:00 (CST-6)
Location: CARROLL NEU ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Carroll Airport AWOS recorded heavy rainfall of 2.54 inches over the last 24 hours.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 04:15:00 to 19-JUN-18 04:15:00 (CST-6)
Location: OGDEN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer reported heavy rainfall of 3.07 inches over the last 24 hours.

Heavy Rain in BOONE, IOWA
From 18-JUN-18 06:00:00 to 19-JUN-18 06:00:00 (CST-6)
Location: OGDEN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 3.00 inches over the last 24 hours.

Heavy Rain in DALLAS, IOWA
From 18-JUN-18 05:55:00 to 19-JUN-18 05:55:00 (CST-6)
Location: PERRY MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Perry Airport AWOS recorded heavy rainfall of 2.18 inches over the last 24 hours.

Heavy Rain in CRAWFORD, IOWA
From 18-JUN-18 05:55:00 to 19-JUN-18 05:55:00 (CST-6)
Location: DENISON MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Denison Airport AWOS recorded heavy rainfall of 3.14 inches over the last 24 hours.

Thunderstorm Wind in HAMILTON, IOWA
From 18-JUN-18 15:00:00 to 18-JUN-18 15:00:00 (CST-6)
Location: WEBSTER CITY
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Social Media

Public relayed a picture of a large tree down in town.