A very moist airmass was in place over Iowa with precipitable water values over 2 inches.  The atmosphere was relatively unstable with CAPE around 2000 J/kg and shear around 30 kts.  A synoptic warm frontal boundary was located over northern Iowa, however a weak outflow boundary that remained from prior convection remained just south of the state.  As the low level jet increased in the evening, thunderstorms formed over southwest Iowa.  The thunderstorms became a slow moving MCS as it drifted northeast.  They produced heavy rainfall with two to four inches common from southwest into central Iowa.  The heaviest rainfall report was in Cass County at Massena with 4.9 inches.  Some local flooding occurred, however there were no reports of either significant flooding or of severe weather with the storms.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: HERROLD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 2.35 inches.

Heavy Rain in DALLAS, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: GRANGER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 2.35 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: ORALABOR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 2.35 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: BONDURANT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall in the past 24 hours was 2.68 inches.

Heavy Rain in DALLAS, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: ADEL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall in the past 24 hours was 3.96 inches.

Heavy Rain in CASS, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: MASSENA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall in the past 24 hours was 4.90 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: WINDSOR HGTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall in the past 24 hours was 3.49 inches near Waveland Golf Course.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: ASHAWA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 2.35 inches near I-35 and Mills Civic Parkway.

Heavy Rain in ADAMS, IOWA
From 28-AUG-14 20:30:00 to 28-AUG-14 20:30:00 (CST-6)
Location: CORNING MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall since 1800 CST was 2.5 inches.

Heavy Rain in DALLAS, IOWA
From 28-AUG-14 21:45:00 to 28-AUG-14 21:45:00 (CST-6)
Location: GRANGER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Rainfall in the past 24 hours was 1.87 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: URBANDALE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 3.00 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: CLOVER HILLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Rainfall in the past 12 hours was 2.27 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: POLK CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 3.57 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: ANKENY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 3 inches.

Heavy Rain in MADISON, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: EARLHAM
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 3.06 inches.

Heavy Rain in MADISON, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: WINTERSET
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 3.00 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: WINDSOR HGTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 3.53 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: WINDSOR HGTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 3.49 inches.

Heavy Rain in WARREN, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: SPRING HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Rainfall in the past 24 hours was 3.19 inches.

Heavy Rain in STORY, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: AMES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 3.25 inches.

Heavy Rain in JASPER, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: NEWTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Rainfall in the past 24 hours was 2.20 inches.

Heavy Rain in ADAIR, IOWA
From 29-AUG-14 06:00:00 to 29-AUG-14 06:00:00 (CST-6)
Location: GREENFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Rainfall in the past 24 hours was 2.10 inches.

Heavy Rain in POLK, IOWA
From 29-AUG-14 02:00:00 to 29-AUG-14 02:00:00 (CST-6)
Location: WINDSOR HGTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Rainfall in the past 24 hours was 3.96 inches. Total from 2030 CST until 0200 CST was 2.75 inches.