Very moist and unstable air moved over Iowa during the early morning of the 25th.  A warm front was located to the south of the state as a series of strong upper level disturbances lifted northeast across the central U.S.  The jet stream was unseasonably strong with a jet of 100 kts lifting northeast out of the southwest U.S.   The airmass was quite unstable with lifted indices around -8 C., and CAPE values of around 2500 J/kg.  This set the stage for a severe weather event that was more driven by strong dynamics then by further destabilization of the atmosphere.  Thunderstorms moved into southwest Iowa from eastern Nebraska during the morning hours.  The storms took on more of a bow echo type configuration as the raced east and northeast across southwest and central Iowa at 45 to 55 kts.  There were several reports of high winds and tree damage as the storms passed.  A few of the stronger storms produced hail with golf ball size hail reported south of Mount Ayr in Ringgold County.

Thunderstorm Wind in TAYLOR, IOWA
From 25-AUG-04 10:42:00 to 25-AUG-04 10:42:00 (CST)
Location: BEDFORD ARPT
Magnitude: 52 EG
Property damage: 2K
Crop damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in TAYLOR, IOWA
From 25-AUG-04 10:54:00 to 25-AUG-04 10:54:00 (CST)
Location: BEDFORD
Magnitude: 52 EG
Property damage: 2K
Crop damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in MARION, IOWA
From 25-AUG-04 12:20:00 to 25-AUG-04 12:20:00 (CST)
Location: KNOXVILLE
Magnitude: 52 EG
Property damage: 2K
Crop damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in DECATUR, IOWA
From 25-AUG-04 11:50:00 to 25-AUG-04 11:50:00 (CST)
Location: GRAND RIVER
Magnitude: 50 EG
Property damage: 3K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in APPANOOSE, IOWA
From 25-AUG-04 13:08:00 to 25-AUG-04 13:08:00 (CST)
Location: MORAVIA
Magnitude: 52 EG
Property damage: 15K
Crop damage: 1K
Reported by: NEWSPAPER

Hail in RINGGOLD, IOWA
From 25-AUG-04 11:23:00 to 25-AUG-04 11:23:00 (CST)
Location: MT AYR
Magnitude: 1.75 
Property damage: 5K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in RINGGOLD, IOWA
From 25-AUG-04 11:23:00 to 25-AUG-04 11:23:00 (CST)
Location: MT AYR
Magnitude: 52 EG
Property damage: 2K
Crop damage: 2K
Reported by: LAW ENFORCEMENT

Hail in ADAMS, IOWA
From 25-AUG-04 11:30:00 to 25-AUG-04 11:30:00 (CST)
Location: PRESCOTT
Magnitude: 0.75 
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in CLARKE, IOWA
From 25-AUG-04 11:55:00 to 25-AUG-04 11:55:00 (CST)
Location: OSCEOLA
Magnitude: 52 EG
Property damage: 5K
Crop damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in MONROE, IOWA
From 25-AUG-04 13:08:00 to 25-AUG-04 13:08:00 (CST)
Location: ALBIA
Magnitude: 50 EG
Property damage: 2K
Reported by: NEWSPAPER

Thunderstorm Wind in TAYLOR, IOWA
From 25-AUG-04 10:50:00 to 25-AUG-04 10:50:00 (CST)
Location: GRAVITY
Magnitude: 52 EG
Property damage: 5K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in TAYLOR, IOWA
From 25-AUG-04 11:05:00 to 25-AUG-04 11:05:00 (CST)
Location: LENOX
Magnitude: 50 EG
Property damage: 2K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in MAHASKA, IOWA
From 25-AUG-04 12:55:00 to 25-AUG-04 12:55:00 (CST)
Location: OSKALOOSA
Magnitude: 50 EG
Property damage: 1K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in WAPELLO, IOWA
From 25-AUG-04 13:26:00 to 25-AUG-04 13:26:00 (CST)
Location: BLAKESBURG
Magnitude: 52 EG
Property damage: 2K
Crop damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in WAPELLO, IOWA
From 25-AUG-04 12:44:00 to 25-AUG-04 12:44:00 (CST)
Location: OTTUMWA
Magnitude: 52 EG
Property damage: 5K
Reported by: TRAINED SPOTTER