Multiple waves of thunderstorms rolled through the state on the 5th and into the beginning of the 6th, providing the state with widespread rainfall and strong to severe thunderstorms. The primary result of the storms was heavy rainfall in the 2 to 4 plus inch range, though damaging winds and severe hail were also observed.
The setup included a a boundary off to the west and northwest that allowed for convection to initiate in South Dakota and eventually move towards the state. Additionally, as the day wore on, the boundary in question moved into Iowa and allowed for additional rounds of convection to form.  During the early morning hours of the 5th, a very unstable air mass over the South Dakota, Nebraska, Iowa, Minnesota was present, including MUCAPE values around 3000+ J/kg. Additionally, marginally supportive effective bulk shear was present (30 to 40 kts) and downdraft CAPE values in excess of 1000 J/kg.  During the daytime hours, the environment predominantly became less supportive for severe storms with reductions in effective bulk shear and downdraft CAPE, though a highly unstable environment remained. Resulting reports included the majority of severe reports being wind related during the early morning to morning hours, followed by rounds of strong, but sub-severe, storms throughout the day.

Thunderstorm Wind in HAMILTON, IOWA
From 05-AUG-18 08:20:00 to 05-AUG-18 08:20:00 (CST-6)
Location: WEBSTER CITY
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported trees down, power lines down and power outages. Some streets were partially blocked by trees with some damage to structures. Time estimated by radar.

Thunderstorm Wind in HAMILTON, IOWA
From 05-AUG-18 08:37:00 to 05-AUG-18 08:37:00 (CST-6)
Location: WEBSTER CITY
Magnitude: 56.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Social Media

Large branches of 10 to 12 inch diameter snapped off trees. Some power lines down in town.

Heavy Rain in BUTLER, IOWA
From 05-AUG-18 07:00:00 to 06-AUG-18 07:00:00 (CST-6)
Location: KESLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 3.16 inches over the last 24 hours.

Thunderstorm Wind in FRANKLIN, IOWA
From 05-AUG-18 08:33:00 to 05-AUG-18 08:33:00 (CST-6)
Location: BEEDS LAKE ARPT
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported tree branches down at Beed's Lake State Park Campground.

Thunderstorm Wind in BUTLER, IOWA
From 05-AUG-18 09:11:00 to 05-AUG-18 09:11:00 (CST-6)
Location: APLINGTON
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported a large 8 to 10 inch diameter tree branch snapped.

Thunderstorm Wind in PALO ALTO, IOWA
From 05-AUG-18 03:16:00 to 05-AUG-18 03:16:00 (CST-6)
Location: CURLEW
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree branches down, including one on a house. Time estimated by radar.

Thunderstorm Wind in PALO ALTO, IOWA
From 05-AUG-18 03:21:00 to 05-AUG-18 03:21:00 (CST-6)
Location: MALLARD
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported tree branches down, including one on a church. Time estimated by radar.

Thunderstorm Wind in POCAHONTAS, IOWA
From 05-AUG-18 03:27:00 to 05-AUG-18 03:27:00 (CST-6)
Location: BLANDEN
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported large tree limbs down and shingles off roofs. Time estimated by radar.

Thunderstorm Wind in FRANKLIN, IOWA
From 05-AUG-18 04:45:00 to 05-AUG-18 04:45:00 (CST-6)
Location: ACKLEY
Magnitude: 59.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported tree damage in town, and their home weather station measured a 68 mph gust. Time estimated by radar.

Thunderstorm Wind in BLACK HAWK, IOWA
From 05-AUG-18 05:30:00 to 05-AUG-18 05:30:00 (CST-6)
Location: DUNKERTON
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Social Media

Public shared a picture of a 10 inch tree limb down on the ground, which also took down a power line.

Thunderstorm Wind in CARROLL, IOWA
From 05-AUG-18 23:05:00 to 05-AUG-18 23:05:00 (CST-6)
Location: CARROLL
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported 3 to 4 inch diameter branches down in Carroll from the evening storms. Time estimated from radar.

Thunderstorm Wind in WEBSTER, IOWA
From 05-AUG-18 03:50:00 to 05-AUG-18 03:50:00 (CST-6)
Location: FT DODGE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 60 plus MPH winds near John F Kennedy park. Time estimated.

Lightning in WEBSTER, IOWA
From 05-AUG-18 14:30:00 to 05-AUG-18 14:30:00 (CST-6)
Location: FT DODGE
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Newspaper

Fort Dodge Messenger reported that lightning struck a house and resulted in a small fire behind the fuse box.

Hail in GRUNDY, IOWA
From 05-AUG-18 19:01:00 to 05-AUG-18 19:01:00 (CST-6)
Location: GRUNDY CENTER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported mostly pea to nickel sized hail, but a few stones as large as quarters were mixed in.

Thunderstorm Wind in HAMILTON, IOWA
From 05-AUG-18 21:22:00 to 05-AUG-18 21:22:00 (CST-6)
Location: WEBSTER CITY ARPT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Webster City Municipal Airport AWOS recorded a peak wind gust of 59 mph.

Heavy Rain in HARDIN, IOWA
From 04-AUG-18 23:01:00 to 05-AUG-18 23:01:00 (CST-6)
Location: ACKLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported a 24 hour heavy rainfall total of 3.55 inches.

Heavy Rain in BLACK HAWK, IOWA
From 05-AUG-18 05:15:00 to 06-AUG-18 01:45:00 (CST-6)
Location: DEWAR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 3.50 inches. Also reported that the creek that runs through Dewar and routes into Elk Run was about half full.

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

CoCoRaHS observer recorded heavy rainfall of 5.11 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 05-AUG-18 05:00:00 to 06-AUG-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 5.40 inches over the last 24 hours.

Heavy Rain in HUMBOLDT, IOWA
From 05-AUG-18 05:14:00 to 06-AUG-18 05:14:00 (CST-6)
Location: DAKOTA CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.28 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 05-AUG-18 03:45:00 to 06-AUG-18 05:29:00 (CST-6)
Location: BADGER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 4.70 inches from the multiple rounds of storms.

Heavy Rain in GRUNDY, IOWA
From 05-AUG-18 05:30:00 to 06-AUG-18 05:30:00 (CST-6)
Location: GRUNDY CENTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

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

Heavy Rain in WRIGHT, IOWA
From 05-AUG-18 03:45:00 to 06-AUG-18 05:34:00 (CST-6)
Location: EAGLE GROVE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 4.50 inches from the multiple rounds of rainfall.

Heavy Rain in BLACK HAWK, IOWA
From 05-AUG-18 05:15:00 to 06-AUG-18 05:38:00 (CST-6)
Location: DEWAR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 4.50 inches from the multiple rounds of storms.

Heavy Rain in BUTLER, IOWA
From 05-AUG-18 05:00:00 to 06-AUG-18 05:45:00 (CST-6)
Location: PARKERSBURG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 3.77 inches from the multiple rounds of storms.

Heavy Rain in HUMBOLDT, IOWA
From 05-AUG-18 18:45:00 to 06-AUG-18 05:55:00 (CST-6)
Location: PIONEER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported heavy rainfall of 4.50 inches from the overnight storms.

Heavy Rain in CALHOUN, IOWA
From 05-AUG-18 11:00:00 to 06-AUG-18 05:57:00 (CST-6)
Location: MANSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Local ABC Station (5) reported heavy rainfall of 4.78 inches in Manson since noon on Sunday. Heavy rainfall of 5.46 inches was seen since Saturday night as well.

Heavy Rain in BLACK HAWK, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: (ALO)WATERLOO MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Waterloo Regional Airport ASOS recorded heavy rainfall of 3.69 inches over the last 24 hours.

Heavy Rain in BREMER, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 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 3.92 inches over the last 24 hours.

Heavy Rain in FRANKLIN, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-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 2.17 inches over the last 24 hours.

Heavy Rain in GRUNDY, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: CONRAD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.14 inches over the last 24 hours.

Heavy Rain in HARDIN, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: ELDORA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 2.16 inches over the last 24 hours.

Heavy Rain in HARDIN, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-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 3.47 inches over the last 24 hours.

Heavy Rain in POCAHONTAS, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: VARINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS observer recorded heavy rainfall of 3.71 inches over the last 24 hours.

Heavy Rain in TAMA, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: TRAER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.13 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Fort Dodge AWOS recorded heavy rainfall of 5.22 inches over the last 24 hours.

Heavy Rain in WEBSTER, IOWA
From 05-AUG-18 06:00:00 to 06-AUG-18 06:00:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 5.95 inches over the last 24 hours.

Heavy Rain in CALHOUN, IOWA
From 05-AUG-18 07:30:00 to 06-AUG-18 06:10:00 (CST-6)
Location: MANSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 5.50 inches.

Heavy Rain in CALHOUN, IOWA
From 05-AUG-18 07:30:00 to 06-AUG-18 06:30:00 (CST-6)
Location: MANSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of at least 5 inches. The rainfall overflowed the top of the rain gauge.

Heavy Rain in CALHOUN, IOWA
From 05-AUG-18 07:15:00 to 06-AUG-18 06:38:00 (CST-6)
Location: POMEROY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 5.5 inches.

Heavy Rain in BUTLER, IOWA
From 05-AUG-18 09:00:00 to 06-AUG-18 06:50:00 (CST-6)
Location: KESLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 3.10 inches.

Heavy Rain in BLACK HAWK, IOWA
From 05-AUG-18 09:45:00 to 06-AUG-18 07:00:00 (CST-6)
Location: HUDSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 4.00 inches.

Heavy Rain in BLACK HAWK, IOWA
From 05-AUG-18 09:15:00 to 06-AUG-18 07:00:00 (CST-6)
Location: CEDAR FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 4.48 inches.

Heavy Rain in HUMBOLDT, IOWA
From 05-AUG-18 07:00:00 to 06-AUG-18 07:00:00 (CST-6)
Location: DAKOTA CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer recorded heavy rainfall of 2.17 inches over the last 24 hours.

Heavy Rain in WRIGHT, IOWA
From 05-AUG-18 08:15:00 to 06-AUG-18 04:00:00 (CST-6)
Location: CLARION
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 3.3 inches.

Heavy Rain in GRUNDY, IOWA
From 05-AUG-18 09:15:00 to 06-AUG-18 07:51:00 (CST-6)
Location: WELLSBURG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

KWWL TV shared public heavy rainfall report of 2.90 inches.

Heavy Rain in BUTLER, IOWA
From 05-AUG-18 09:15:00 to 06-AUG-18 09:00:00 (CST-6)
Location: NEW HARTFORD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 4.00 inches.

Thunderstorm Wind in HANCOCK, IOWA
From 05-AUG-18 04:25:00 to 05-AUG-18 04:25:00 (CST-6)
Location: GARNER
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: COOP Observer

Large branches of 3 to 4 inches diameter downed in town.

Lightning in HARDIN, IOWA
From 05-AUG-18 08:40:00 to 05-AUG-18 08:40:00 (CST-6)
Location: IOWA FALLS
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A lightning strike blew a transformer causing a loss of power, internet and cell service.

Thunderstorm Wind in HARDIN, IOWA
From 05-AUG-18 09:02:00 to 05-AUG-18 09:02:00 (CST-6)
Location: IOWA FALLS
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tree damage was reported in town with some limbs down.