During the evening hours an unseasonably strong cold front advanced into Iowa from the northwest.  The airmass was capped, however the very strong dynamics were able to overcome the cap and a narrow line of strong to severe thunderstorms developed ahead of the front.  For the most part, the storms produced strong winds as high as 75 MPH.  The line had several bowing segments along it, each causing high wind.  For the most part the damage was limited to trees and power lines.  A window was blown out of a house in Roland in Story County.  Also, the high winds tore off some of the siding from a school building in Creston in Union County.  Some hail was reported during the early stages of the squall lines development.  Golf ball size hail fell southwest of Emmetsburg in Palo Alto County.  A few reports of hail three quarters of an inch to an inch in diameter were received.  As the storms moved through Emmet County, lightning struck a corn crib on a farm in rural Ringsted.  The crib was set on fire and destroyed before fire fighters were able to contain the blaze.

Thunderstorm Wind in UNION, IOWA
From 17-AUG-02 04:13:00 to 17-AUG-02 04:13:00 (CST)
Location: AFTON
Magnitude: 52 M
Property damage: 3K
Reported by: AWOS,ASOS,MESONET,ETC

Hail in WRIGHT, IOWA
From 17-AUG-02 02:37:00 to 17-AUG-02 02:37:00 (CST)
Location: CLARION
Magnitude: 0.75 
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in MARSHALL, IOWA
From 17-AUG-02 03:55:00 to 17-AUG-02 03:55:00 (CST)
Location: MARSHALLTOWN
Magnitude: 54 E
Property damage: 10K
Crop damage: 5K
Reported by: NEWSPAPER

Thunderstorm Wind in BOONE, IOWA
From 17-AUG-02 02:52:00 to 17-AUG-02 02:52:00 (CST)
Location: BOXHOLM
Magnitude: 65 E
Property damage: 25K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in BOONE, IOWA
From 17-AUG-02 02:48:00 to 17-AUG-02 02:48:00 (CST)
Location: PILOT MOUND
Magnitude: 57 E
Property damage: 5K
Crop damage: 5K
Reported by: UNKNOWN

Hail in PALO ALTO, IOWA
From 16-AUG-02 23:27:00 to 16-AUG-02 23:27:00 (CST)
Location: EMMETSBURG
Magnitude: 1.75 
Property damage: 20K
Crop damage: 15K
Reported by: AMATEUR RADIO

Thunderstorm Wind in WEBSTER, IOWA
From 17-AUG-02 02:30:00 to 17-AUG-02 02:30:00 (CST)
Location: FT DODGE
Magnitude: 57 E
Property damage: 20K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Lightning in EMMET, IOWA
From 16-AUG-02 23:30:00 to 16-AUG-02 23:30:00 (CST)
Location: RINGSTED
Property damage: 25K
Reported by: NEWSPAPER

Thunderstorm Wind in STORY, IOWA
From 17-AUG-02 03:28:00 to 17-AUG-02 03:28:00 (CST)
Location: ROLAND
Magnitude: 57 E
Property damage: 10K
Crop damage: 5K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in UNION, IOWA
From 17-AUG-02 03:03:00 to 17-AUG-02 03:03:00 (CST)
Location: CRESTON
Magnitude: 53 M
Property damage: 5K
Crop damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

Thunderstorm Wind in CRAWFORD, IOWA
From 17-AUG-02 01:30:00 to 17-AUG-02 01:30:00 (CST)
Location: VAIL
Magnitude: 61 E
Property damage: 20K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Hail in PALO ALTO, IOWA
From 16-AUG-02 23:10:00 to 16-AUG-02 23:10:00 (CST)
Location: AYRSHIRE
Magnitude: 1.00 
Property damage: 5K
Crop damage: 10K
Reported by: BROADCAST MEDIA

Thunderstorm Wind in DECATUR, IOWA
From 17-AUG-02 03:45:00 to 17-AUG-02 03:45:00 (CST)
Location: LAMONI ARPT
Magnitude: 52 M
Property damage: 3K
Reported by: AWOS,ASOS,MESONET,ETC