A very moist and unstable airmass remained in place over Iowa with CAPE values in the 3000 to 4500 J/kg range and lifted index values around -8 C.  A boundary extended nearly east to west across the southern half of Iowa during the day from the previous night's convection.  High temperatures reached the low 90s south of the boundary with mid to upper 80s to its north.  Dew points were in the low to mid 70s.  Deep moisture was in place with precipitable water values in the 2 to 2.25 inch range.  An MCV was lifting northeast across northeast Nebraska during the day.  Thunderstorms formed over southeast Nebraska into southern Iowa during the late afternoon and evening hours.  Downdraft CAPE was in the 1000 to 1500 J/kg range with CAPE in the -10 to -30 C. layer of the atmosphere in the 500 to 700 J/kg range.  The freezing level remained quite high, in the 14,500 to 15,900 foot range.  This limited the hail production.  Effective shear across the area was between 30 and 40 kts with the LCL 1000 to 1250 meters.  There was one report of nickel size hail during the event.  This occurred in Wayne County, south of Humeston.  The rest of the severe weather was in the form of high winds.  Several of the storms produced winds of 60 to 70 MPH.  A grain bin was destroyed south of Humeston by high winds.  Two semitrailer trucks were jackknifed as the result of high winds on Interstate 35 in Warren County near Bevington.  In Taylor County, thunderstorms that developed later in the evening flattened a barn west of Bedford.  The storms produced copious amounts of rainfall with 2 to as much as 4 inches of rain falling in Warren County, resulting in flash flooding.  Water was running 6 inches deep across Interstate 35 between mile post 48 and mile post 50.

Thunderstorm Wind in WARREN, IOWA
From 07-AUG-07 18:57:00 to 07-AUG-07 18:57:00 (CST-6)
Location: NORWALK
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in WARREN, IOWA
From 07-AUG-07 18:45:00 to 07-AUG-07 20:30:00 (CST-6)
Location: NEW VIRGINIA
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 25.00K
Reported by: Law Enforcement

Thunderstorm Wind in TAYLOR, IOWA
From 07-AUG-07 17:25:00 to 07-AUG-07 17:25:00 (CST-6)
Location: LENOX
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in WAYNE, IOWA
From 07-AUG-07 16:44:00 to 07-AUG-07 16:44:00 (CST-6)
Location: HUMESTON
Magnitude: 61.00 EG
Property damage: 30.00K
Crop damage: 5.00K
Reported by: Emergency Manager

Thunderstorm Wind in UNION, IOWA
From 07-AUG-07 17:48:00 to 07-AUG-07 17:48:00 (CST-6)
Location: CRESTON
Magnitude: 53.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in WAYNE, IOWA
From 07-AUG-07 16:50:00 to 07-AUG-07 16:50:00 (CST-6)
Location: BENTONVILLE
Magnitude: 0.88 
Property damage: 3.00K
Crop damage: 25.00K
Reported by: Emergency Manager

Thunderstorm Wind in WARREN, IOWA
From 07-AUG-07 18:45:00 to 07-AUG-07 18:45:00 (CST-6)
Location: BEVINGTON
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Thunderstorm Wind in WARREN, IOWA
From 07-AUG-07 18:39:00 to 07-AUG-07 18:39:00 (CST-6)
Location: INDIANOLA
Magnitude: 50.00 EG
Property damage: 4.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in UNION, IOWA
From 07-AUG-07 17:48:00 to 07-AUG-07 17:48:00 (CST-6)
Location: CRESTON ARPT
Magnitude: 53.00 MG
Property damage: 2.00K
Crop damage: 10.00K
Reported by: AWOS

Thunderstorm Wind in MARION, IOWA
From 07-AUG-07 19:05:00 to 07-AUG-07 19:05:00 (CST-6)
Location: DUNREATH
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Thunderstorm Wind in TAYLOR, IOWA
From 07-AUG-07 21:30:00 to 07-AUG-07 21:30:00 (CST-6)
Location: BEDFORD
Magnitude: 70.00 EG
Property damage: 50.00K
Crop damage: 25.00K
Reported by: Law Enforcement