A mid level shortwave trough provided the focus for storm development late in the evening of August 30th. Initial disorganized convection across northern Iowa became more organized moving across central and into southern Iowa where better instability and steep lapse rates allowed deeper convection. Storms grew upscale into a bowing line that produced damaging gusts from 55 to 65 mph.

Thunderstorm Wind in CRAWFORD, IOWA
From 30-AUG-21 21:25:00 to 30-AUG-21 21:25:00 (CST-6)
Location: DELOIT
Magnitude: 54.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Second hand, delayed report of wind damage from just north of Vail to east of Deloit. Hog barn roof blown off, several trees uprooted, and some hail damage. Time estimated by radar.

Hail in CRAWFORD, IOWA
From 30-AUG-21 21:30:00 to 30-AUG-21 21:30:00 (CST-6)
Location: VAIL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter sized hail with 50 to 60 mph winds.

Thunderstorm Wind in AUDUBON, IOWA
From 30-AUG-21 22:04:00 to 30-AUG-21 22:04:00 (CST-6)
Location: FISCUS
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 59 mph wind just measured by personal weather station.

Thunderstorm Wind in DALLAS, IOWA
From 30-AUG-21 22:22:00 to 30-AUG-21 22:22:00 (CST-6)
Location: MORAN
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported 51 knot gust on personal instrument.

Lightning in STORY, IOWA
From 30-AUG-21 22:40:00 to 30-AUG-21 22:40:00 (CST-6)
Location: ONTARIO
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Story County emergency manager reported lightning striking a house causing a small fire with fire department investigating to confirm.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 22:42:00 to 30-AUG-21 22:42:00 (CST-6)
Location: POLK CITY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS Employee reports wind gusts near 60 mph in Polk City with branches down.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 22:51:00 to 30-AUG-21 22:51:00 (CST-6)
Location: DES MOINES
Magnitude: 54.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Large tree down across the road. Time estimated from KOAX radar.

Thunderstorm Wind in DALLAS, IOWA
From 30-AUG-21 22:53:00 to 30-AUG-21 22:53:00 (CST-6)
Location: HADDEN HILL
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winds estimated at 60 to 65 mph.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 22:56:00 to 30-AUG-21 22:56:00 (CST-6)
Location: DES MOINES
Magnitude: 54.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A 12 inch diameter tree limb fell on a power line, causing a house fire. Multiple 5 to 6 inch diameter branches down in the area as well. Time estimated by radar.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 22:57:00 to 30-AUG-21 22:57:00 (CST-6)
Location: FT DES MOINES
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tree down and wires down. Time estimated from KOAX radar.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 22:58:00 to 30-AUG-21 22:58:00 (CST-6)
Location: (DSM)DES MOINES INTL
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in ADAIR, IOWA
From 30-AUG-21 23:02:00 to 30-AUG-21 23:02:00 (CST-6)
Location: HOWE
Magnitude: 54.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A 12 TO 14 inch diameter tree limb down. Time estimated by radar.

Thunderstorm Wind in POLK, IOWA
From 30-AUG-21 23:17:00 to 30-AUG-21 23:17:00 (CST-6)
Location: WINDSOR HGTS
Magnitude: 51.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wires down near 55th and University Avenue.

Thunderstorm Wind in ADAIR, IOWA
From 30-AUG-21 23:35:00 to 30-AUG-21 23:35:00 (CST-6)
Location: GREENFIELD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Minor tree damage. Time estimated by radar.

Thunderstorm Wind in CASS, IOWA
From 30-AUG-21 23:51:00 to 30-AUG-21 23:51:00 (CST-6)
Location: LEWIS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Power lines down in Lewis. Time estimated by radar.

Heavy Rain in APPANOOSE, IOWA
From 30-AUG-21 05:34:00 to 31-AUG-21 05:34:00 (CST-6)
Location: CENTERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24 hour rain total of 2.91 inches.

Heavy Rain in TAYLOR, IOWA
From 30-AUG-21 05:45:00 to 31-AUG-21 05:45:00 (CST-6)
Location: GUSS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24 hour rain total of 2.79 inches.

Heavy Rain in CASS, IOWA
From 30-AUG-21 05:49:00 to 31-AUG-21 05:49:00 (CST-6)
Location: ANITA MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24 hour rain total of 2.04 inches.

Heavy Rain in APPANOOSE, IOWA
From 30-AUG-21 06:00:00 to 31-AUG-21 06:00:00 (CST-6)
Location: CENTERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24 hour rain total of 3.05 inches.

Heavy Rain in CASS, IOWA
From 30-AUG-21 06:00:00 to 31-AUG-21 06:00:00 (CST-6)
Location: ATLANTIC ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

A 24 hour rain total of 2.07 inches.

Heavy Rain in CASS, IOWA
From 30-AUG-21 06:05:00 to 31-AUG-21 06:05:00 (CST-6)
Location: ATLANTIC
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24 hour rain total of 2.10 inches.

Heavy Rain in ADAMS, IOWA
From 30-AUG-21 06:17:00 to 31-AUG-21 06:17:00 (CST-6)
Location: CORNING MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24 hour rain total of 2.22 inches.

Heavy Rain in CLARKE, IOWA
From 30-AUG-21 06:18:00 to 31-AUG-21 06:18:00 (CST-6)
Location: MURRAY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24 hour rain total of 2.10 inches.

Heavy Rain in APPANOOSE, IOWA
From 30-AUG-21 07:00:00 to 31-AUG-21 07:00:00 (CST-6)
Location: FORBUSH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A 24 hour rain total of 2.80 inches.

Heavy Rain in CASS, IOWA
From 30-AUG-21 08:00:00 to 31-AUG-21 08:00:00 (CST-6)
Location: GRISWOLD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A 24 hour rain total of 4.10 inches.

Heavy Rain in CASS, IOWA
From 30-AUG-21 19:00:00 to 31-AUG-21 19:00:00 (CST-6)
Location: GRISWOLD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A 24 hour rain total of 4.00 inches.