Thunderstorms that developed over central Nebraska earlier during the day of August 12th turned severe as they pushed southeast into southwest Iowa during the late afternoon and early evening hours of August 12th.  Despite a large scale upper ridge in place across the region, the storms became severe as they tapped a large pocket of instability that was located over eastern Nebraska.  The thunderstorms produced a large cold pool and produced scattered areas of strong and damaging winds as several bow echoes moved across the area.
In addition, torrential rain occurred within the strongest part of the complex with near zero visibilities causing conditions to become like nightfall prompting street lights to come on.

Heavy Rain in PAGE, IOWA
From 12-AUG-07 18:10:00 to 12-AUG-07 18:10:00 (CST-6)
Location: CLARINDA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

One inch of rain fell in 15 minutes causing street flooding in Clarinda.

Thunderstorm Wind in MILLS, IOWA
From 12-AUG-07 16:48:00 to 12-AUG-07 16:48:00 (CST-6)
Location: PACIFIC JCT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm Wind in SHELBY, IOWA
From 12-AUG-07 16:55:00 to 12-AUG-07 16:55:00 (CST-6)
Location: HARLAN MUNI ARPT
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

A thunderstorm wind gust of 58 mph was measured by the Harlan AWOS.  The strong winds downed trees in Harlan damaging some vehicles and knocking down power lines.  The winds also caused some farm outbuilding damage in the area.

Thunderstorm Wind in MILLS, IOWA
From 12-AUG-07 16:53:00 to 12-AUG-07 16:53:00 (CST-6)
Location: GLENWOOD
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm wind gusts estimated at over 60 mph blew a pickup truck off of Interstate 29.

Thunderstorm Wind in PAGE, IOWA
From 12-AUG-07 18:24:00 to 12-AUG-07 18:24:00 (CST-6)
Location: CLARINDA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds estimated at 60 mph knocked down some trees blocking roads in town.

Thunderstorm Wind in PAGE, IOWA
From 12-AUG-07 17:38:00 to 12-AUG-07 17:38:00 (CST-6)
Location: ESSEX
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds estimated at 60 mph blew down trees blocking a road in the area.

Thunderstorm Wind in PAGE, IOWA
From 12-AUG-07 18:29:00 to 12-AUG-07 18:29:00 (CST-6)
Location: COLLEGE SPGS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a large tree across a road in town.

Thunderstorm Wind in HARRISON, IOWA
From 12-AUG-07 16:24:00 to 12-AUG-07 16:25:00 (CST-6)
Location: MISSOURI VLY
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds estimated at 60 mph caused 4 or 5 trees to fall onto power lines in Missouri Valley.

Thunderstorm Wind in MILLS, IOWA
From 12-AUG-07 17:02:00 to 12-AUG-07 17:20:00 (CST-6)
Location: GLENWOOD
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds estimated at over 60 mph blew a semi truck off of Interstate 29 and knocked down tree limbs up to 6 inches in diameter which downed some power lines in town.  The strong winds lasted for at least 15 minutes.

Thunderstorm Wind in MONTGOMERY, IOWA
From 12-AUG-07 17:30:00 to 12-AUG-07 17:30:00 (CST-6)
Location: RED OAK
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds estimated at 60 mph blew a power pole over on a car.  The car was occupied at the time and the power was live, but the occupants escaped unharmed.  The winds also brought down tree limbs and power lines in the area.

Thunderstorm Wind in POTTAWATTAMIE, IOWA
From 12-AUG-07 16:35:00 to 12-AUG-07 16:35:00 (CST-6)
Location: AVOCA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A thunderstorm wind gust estimated at 60 mph was reported near Avoca.