A cold front moved into Iowa during the evening hours.  Deep moisture was drawn north ahead of the front with precipitable water values approaching 1.5 inches, very near the all time record for the time of the year.  The atmosphere was quite warm with the freezing level in the 12,000 to 14,000 range.  For late September, CAPE values were fairly high, around 2000 J/kg, but the atmosphere was weakly sheared with 20 to 30 kts of effective shear.  CAPE in the -10 to -30 C. layer of the atmosphere was between 200 to 400 J/kg, while downdraft CAPE was between 600 and 1100 J/kg.  A line of thunderstorms formed ahead of the cold front during the late afternoon.  Actually, the line had formed the night before and had weakened during the day and intensified during maximum heating.  The line moved east and produced hail for the most part with reports of three quarter to 1 inch diameter hail received in several locations across western Iowa.  One storm produced winds around 60 MPH in Dallas County.  Tree limbs were downed and a portion of a 2 foot diameter tree was blown down by the wind.

Hail in GUTHRIE, IOWA
From 23-SEP-08 17:26:00 to 23-SEP-08 17:26:00 (CST-6)
Location: GUTHRIE CENTER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 3.00K
Reported by: Emergency Manager

Dime to penny size hail 1 mile east of Guthrie Center on Highway 44.

Thunderstorm Wind in DALLAS, IOWA
From 23-SEP-08 18:38:00 to 23-SEP-08 18:38:00 (CST-6)
Location: PERRY
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A few 2 to 3 inch diameter tree limbs down about 10 feet long.  A portion of an Elm tree trunk about 2 feet in diameter and 20 to 30 feet was also blown down.

Hail in GUTHRIE, IOWA
From 23-SEP-08 17:36:00 to 23-SEP-08 17:36:00 (CST-6)
Location: FANSLERS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 3.00K
Reported by: Trained Spotter

Trained spotter reports penny to nickel size hail.

Hail in GUTHRIE, IOWA
From 23-SEP-08 18:08:00 to 23-SEP-08 18:08:00 (CST-6)
Location: PANORA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 3.00K
Reported by: Emergency Manager

Hail in GUTHRIE, IOWA
From 23-SEP-08 17:50:00 to 23-SEP-08 17:50:00 (CST-6)
Location: PANORA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 3.00K
Reported by: Emergency Manager

Hail in CASS, IOWA
From 23-SEP-08 20:59:00 to 23-SEP-08 20:59:00 (CST-6)
Location: GRISWOLD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 3.00K
Reported by: Law Enforcement

Mostly dime size hail with some up to penny size.

Hail in CASS, IOWA
From 23-SEP-08 15:30:00 to 23-SEP-08 15:30:00 (CST-6)
Location: LEWIS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Law Enforcement

Hail in CASS, IOWA
From 23-SEP-08 15:36:00 to 23-SEP-08 15:36:00 (CST-6)
Location: LEWIS
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 5.00K
Reported by: Law Enforcement

Hail in CASS, IOWA
From 23-SEP-08 15:37:00 to 23-SEP-08 15:37:00 (CST-6)
Location: LEWIS
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 5.00K
Reported by: Fire Department/Rescue

Hail in CASS, IOWA
From 23-SEP-08 15:40:00 to 23-SEP-08 15:40:00 (CST-6)
Location: ATLANTIC
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 5.00K
Reported by: Law Enforcement

Nickel to quarter size hail was reported.