Wet conditions continued across the state with yet another round of moderate to heavy rainfall on top of already mostly saturated conditions.  A shortwave moving through the upper level flow out of the southwest, a surface front situated to the west and northwest of the state, and strong 850 mb flow were the main contributors to showers and storms.
Conditions were certainly conducive for heavy rainfall, including MUCAPE of at least 1000 J/kg and ranging up to 2000+ J/kg, precipitable water values near and in excess of 2.0 inches, and strong moisture advection into and through the state throughout the event. Additionally, conditions were relatively favorable for a funnel cloud or brief spin up or two with lifted condensation levels predominantly under 750 m, 0-3 km CAPE values around 175-200 J/kg, and 0-1 km storm relative helicity values around 100-150 m2/s2.
In the end, a couple of funnel cloud and brief tornado reports were seen across the most favorable areas in northwest Iowa, followed up by nearly exclusively heavy rainfall and flash flooding reports from southwest Iowa into central Iowa and even parts of northern Iowa.  Greatest reports included multiple 3+ inch reports across northern and northwest Iowa and 2 day totals in excess of 6 inches into parts of central Iowa.

Heavy Rain in EMMET, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: RINGSTED
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 FRANKLIN, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-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 3.70 inches over the last 24 hours.

Flash Flood in MAHASKA, IOWA
From 05-SEP-18 11:00:00 to 05-SEP-18 14:30:00 (CST-6)
Location: NEW SHARON
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water over the road.

Flash Flood in MAHASKA, IOWA
From 05-SEP-18 11:00:00 to 05-SEP-18 14:30:00 (CST-6)
Location: NEW SHARON
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water over the road.

Flood in MAHASKA, IOWA
From 05-SEP-18 14:53:00 to 07-SEP-18 13:00:00 (CST-6)
Location: PEORIA
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 100.00K
Reported by: Emergency Manager

Emergency management reported widespread road closures due to flooding or being washed out across much of the county.

Heavy Rain in KOSSUTH, IOWA
From 04-SEP-18 05:00:00 to 05-SEP-18 05:00:00 (CST-6)
Location: SWEA CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

CoCoRaHS observer recorded heavy rainfall of 3.2 inches over the last 24 hours.

Heavy Rain in PALO ALTO, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: RODMAN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.85 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: ROBERTS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.41 inches over the last 24 hours.

Flash Flood in POWESHIEK, IOWA
From 05-SEP-18 10:49:00 to 05-SEP-18 14:30:00 (CST-6)
Location: TILTON
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 50.00K
Reported by: Emergency Manager

Emergency manager reported several county roads under water, with one state highway closed due to flooding. Several basements were also reported flooding. This is a delayed report.

Flood in FRANKLIN, IOWA
From 05-SEP-18 13:26:00 to 05-SEP-18 14:30:00 (CST-6)
Location: LATIMER
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported flooding in and around town.

Heavy Rain in PALO ALTO, IOWA
From 04-SEP-18 05:00:00 to 05-SEP-18 05:00:00 (CST-6)
Location: WEST BEND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 3.36 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 04-SEP-18 05:00:00 to 05-SEP-18 05:00:00 (CST-6)
Location: FT DODGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

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

Heavy Rain in HAMILTON, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: WEBSTER CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.50 inches over the last 24 hours.

Heavy Rain in HAMILTON, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: WEBSTER CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.04 inches over the last 24 hours.

Heavy Rain in WINNEBAGO, IOWA
From 04-SEP-18 05:00:00 to 05-SEP-18 05:00:00 (CST-6)
Location: LAKE MILLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.71 inches over the last 24 hours.

Heavy Rain in WINNEBAGO, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: FOREST CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.34 inches over the last 24 hours.

Heavy Rain in MARION, IOWA
From 04-SEP-18 23:00:00 to 05-SEP-18 14:30:00 (CST-6)
Location: KNOXVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported heavy rainfall of 1.63 inches since midnight and 3.89 inches since Friday.

Heavy Rain in MARION, IOWA
From 04-SEP-18 23:00:00 to 05-SEP-18 14:30:00 (CST-6)
Location: PELLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported heavy rainfall of 3.11 inches since midnight and 6.06 inches since Friday.

Heavy Rain in KOSSUTH, IOWA
From 04-SEP-18 05:55:00 to 05-SEP-18 05:55:00 (CST-6)
Location: ALGONA MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Algona Municipal Airport recorded heavy rainfall of 2.06 inches over the last 24 hours.

Heavy Rain in WINNEBAGO, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 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 2.44 inches over the last 24 hours.

Flash Flood in POWESHIEK, IOWA
From 05-SEP-18 11:00:00 to 05-SEP-18 14:30:00 (CST-6)
Location: FOREST HOME
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water over the road.

Flash Flood in UNION, IOWA
From 05-SEP-18 12:45:00 to 05-SEP-18 14:00:00 (CST-6)
Location: THAYER
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported road closure due to flooding on 275th Street near Yucca Ave. Time and location estimated from radar. This is a delayed report.

Flood in FRANKLIN, IOWA
From 05-SEP-18 08:50:00 to 06-SEP-18 07:30:00 (CST-6)
Location: ALEXANDER
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 250.00K
Reported by: Emergency Manager

Emergency manager reported several road closures due to water over the roadways.

Heavy Rain in HARDIN, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: IOWA FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.00 inches over the last 24 hours.

Heavy Rain in HUMBOLDT, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: DAKOTA CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.08 inches over the last 24 hours.

Tornado in KOSSUTH, IOWA
From 04-SEP-18 14:35:00 to 04-SEP-18 14:37:00 (CST-6)
Location: HOBARTON
Tornado F-scale: EF1
Property damage: 8.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Brief tornado occurred to the west of Algona producing roof damage to a hog confinement building.  The remainder of the path was in rural agricultural land.

Funnel Cloud in KOSSUTH, IOWA
From 04-SEP-18 14:40:00 to 04-SEP-18 14:40:00 (CST-6)
Location: WHITTEMORE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Family members of a trained spotter sent in a video of a funnel cloud.

Heavy Rain in WRIGHT, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: EAGLE GROVE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.01 over the last 24 hours.

Heavy Rain in BUTLER, IOWA
From 04-SEP-18 14:45:00 to 05-SEP-18 09:14:00 (CST-6)
Location: GREENE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported over 4 inches of rain near Coldwater Creek overnight. Water reported to be moving into fields. Location estimated.

Flash Flood in KOSSUTH, IOWA
From 04-SEP-18 16:22:00 to 04-SEP-18 21:50:00 (CST-6)
Location: ALGONA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 50.00K
Reported by: Department of Highways

Iowa DOT reported road closure between County Highway B55 and US 18 due to water over the road.

Flash Flood in MAHASKA, IOWA
From 05-SEP-18 11:00:00 to 05-SEP-18 11:00:00 (CST-6)
Location: OSKALOOSA
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement reported water over the road.

Heavy Rain in BUTLER, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: KESLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.04 inches over the last 24 hours.

Heavy Rain in BUTLER, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: ALLISON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.00 inches over the last 24 hours.

Flash Flood in FRANKLIN, IOWA
From 05-SEP-18 07:00:00 to 05-SEP-18 08:50:00 (CST-6)
Location: ALEXANDER
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 100.00K
Reported by: Emergency Manager

Emergency manager reported several road closures due to water over the roadways.

Flash Flood in RINGGOLD, IOWA
From 05-SEP-18 15:40:00 to 05-SEP-18 15:40:00 (CST-6)
Location: MT AYR MUNI ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 20.00K
Reported by: Emergency Manager

Emergency manager reported road closure at 250th and 270th in Ringgold County due to water over the road.

Flood in FRANKLIN, IOWA
From 05-SEP-18 14:38:00 to 05-SEP-18 14:45:00 (CST-6)
Location: POPEJOY
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported flooding in areas around town.

Flood in POWESHIEK, IOWA
From 05-SEP-18 14:53:00 to 06-SEP-18 13:00:00 (CST-6)
Location: HARTWICK
Flood cause: Heavy Rain
Property damage: 150.00K
Crop damage: 150.00K
Reported by: Emergency Manager

Emergency management reported widespread road closures due to flooding or being washed out across much of the county.

Flood in WRIGHT, IOWA
From 05-SEP-18 08:50:00 to 06-SEP-18 07:30:00 (CST-6)
Location: CLARION ARPT
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 250.00K
Reported by: Emergency Manager

Emergency manager reported several road closures due to water over the roadways.

Heavy Rain in KOSSUTH, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: ALGONA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 4.01 inches over the last 24 hours.

Heavy Rain in KOSSUTH, IOWA
From 04-SEP-18 06:00:00 to 05-SEP-18 06:00:00 (CST-6)
Location: HOBARTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 4.02 inches over the last 24 hours.

Flood in BUTLER, IOWA
From 05-SEP-18 08:50:00 to 06-SEP-18 19:00:00 (CST-6)
Location: AREDALE
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 250.00K
Reported by: Emergency Manager

Emergency manager reported several road closures due to water over the roadways across the county with the worst area near Dumont.

Heavy Rain in KOSSUTH, IOWA
From 04-SEP-18 11:30:00 to 04-SEP-18 17:42:00 (CST-6)
Location: IRVINGTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 5.8 inches with the afternoon activity.

Heavy Rain in PALO ALTO, IOWA
From 04-SEP-18 14:52:00 to 04-SEP-18 17:52:00 (CST-6)
Location: WEST BEND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Local media reported 3 hour heavy rainfall total of 3.6 inches.