An unstable airmass was in place over Iowa during the day on the 7th.  A strong area of convection passed through the state during the morning hours.   Though there was only brief clearing, the airmass was able to recharge as winds strengthened aloft and temperatures began to cool.  An upper level disturbance moved rapidly northeast across the state, setting off another round of severe weather in the form of high winds.  A line of thunderstorms developed from north central into southwest Iowa.  Initially they were ahead of an approaching cold front, but soon outran the support of the front.  The upper level system took over changing the line into series of bow echos.  Winds of 60 MPH were first reported in Dallas County of central Iowa.  The storms raced northeast at 60 MPH or more and moved into Story County.  High winds of 60 to 80 MPH were common with these storms as they moved through.  Large trees were downed by the high winds.  One person was injured as the storms moved through Nevada in Story County.  There were several reports of outbuilding damage and damage to grain bins.  Damage was widespread in Story County.  As a result Governor Vilsack declared Story County a disaster area.  In Hardin County west of Hubbard, two barns were destroyed, killing some of the livestock contained within.  The storms continued to move northeast and caused damage to a house northwest of Frederika in Bremer County.

Thunderstorm Wind in BREMER, IOWA
From 07-SEP-01 15:38:00 to 07-SEP-01 15:38:00 (CST)
Location: FREDERIKA
Magnitude: 52 E
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in BREMER, IOWA
From 07-SEP-01 15:50:00 to 07-SEP-01 15:50:00 (CST)
Location: FREDERIKA
Magnitude: 70 E
Property damage: 25K
Crop damage: 5K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in HARDIN, IOWA
From 07-SEP-01 14:40:00 to 07-SEP-01 14:40:00 (CST)
Location: HUBBARD
Magnitude: 65 E
Property damage: 35K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:10:00 to 07-SEP-01 14:10:00 (CST)
Location: AMES
Magnitude: 52 E
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in GRUNDY, IOWA
From 07-SEP-01 15:15:00 to 07-SEP-01 15:15:00 (CST)
Location: REINBECK
Magnitude: 57 E
Property damage: 15K
Crop damage: 3K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:10:00 to 07-SEP-01 14:10:00 (CST)
Location: AMES
Magnitude: 65 E
Property damage: 30K
Crop damage: 2K
Reported by: GENERAL PUBLIC

Thunderstorm Wind in DALLAS, IOWA
From 07-SEP-01 13:58:00 to 07-SEP-01 13:58:00 (CST)
Location: WAUKEE
Magnitude: 52 E
Property damage: 3K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in BLACK HAWK, IOWA
From 07-SEP-01 15:25:00 to 07-SEP-01 15:25:00 (CST)
Location: CEDAR FALLS
Magnitude: 52 E
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:21:00 to 07-SEP-01 14:21:00 (CST)
Location: NEVADA
Magnitude: 57 E
Property damage: 10K
Crop damage: 3K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:30:00 to 07-SEP-01 14:30:00 (CST)
Location: ZEARING
Magnitude: 64 E
Property damage: 5K
Crop damage: 1K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:10:00 to 07-SEP-01 14:10:00 (CST)
Location: KELLEY
Magnitude: 70 E
Property damage: 40K
Crop damage: 10K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in HARDIN, IOWA
From 07-SEP-01 14:35:00 to 07-SEP-01 14:35:00 (CST)
Location: HUBBARD
Magnitude: 70 E
Property damage: 75K
Crop damage: 10K
Reported by: BROADCAST MEDIA

Thunderstorm Wind in GRUNDY, IOWA
From 07-SEP-01 15:10:00 to 07-SEP-01 15:10:00 (CST)
Location: GRUNDY CENTER
Magnitude: 52 E
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in MARSHALL, IOWA
From 07-SEP-01 14:15:00 to 07-SEP-01 14:15:00 (CST)
Location: MARSHALLTOWN
Magnitude: 52 E
Property damage: 5K
Reported by: AMATEUR RADIO

Thunderstorm Wind in STORY, IOWA
From 07-SEP-01 14:15:00 to 07-SEP-01 14:15:00 (CST)
Location: NEVADA
Magnitude: 65 E
Property damage: 15K
Crop damage: 3K
Reported by: AMATEUR RADIO

Thunderstorm Wind in HARDIN, IOWA
From 07-SEP-01 14:43:00 to 07-SEP-01 14:43:00 (CST)
Location: ELDORA
Magnitude: 52 E
Property damage: 5K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in POLK, IOWA
From 07-SEP-01 14:11:00 to 07-SEP-01 14:11:00 (CST)
Location: WEST DES MOINES
Magnitude: 57 E
Property damage: 10K
Crop damage: 1K
Reported by: NWS EMPLOYEE(OFF DUTY)