A warm front remained in place to the south of Iowa during the overnight hours of the 13th into the morning of the 14th.  The airmass was very unstable to the south of the front with CAPE around 3500 J/kg and lifted indices of -7 to -9 C.  The atmosphere was moderately sheared with 35 to 50 kts of shear available.  CAPE in the -10 to -30 C layer of the atmosphere was between 500 and 800 J/kg.  Downdraft CAPE was just under 1000 J/jg.  Thunderstorms formed over southern Iowa as the low level jet of 35 to 50 kts developed.  Hail began to occur with the storms shortly before midnight over southern Iowa.  Heavy rain was also an issue on already saturated ground with precipitable water values over 1.6 inches.  The storms eventually intensified with severe weather developing.  Golf ball size hail was reported in Madison County at Earlham.  This was one of the larger reports.  Another storm produced hail around 2 inches in diameter in the Huxley area of Story County.  Several reports of hail around an inch to one and one half inches in diameter were received.  Heavy rainfall occurred over central into southeast Iowa.  Rainfall of 3 to 6 inches resulted in flash flooding in Mahaska County, closing Iowa Highway 92 near Oskaloosa.  Once the flash flooding subsided, considerable water remained standing through the area with general flooding continuing.

Hail in STORY, IOWA
From 14-JUN-11 05:08:00 to 14-JUN-11 05:08:00 (CST-6)
Location: IOWA CENTER
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 15.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 14-JUN-11 01:31:00 to 14-JUN-11 01:31:00 (CST-6)
Location: CLOVER HILLS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Flood in MAHASKA, IOWA
From 14-JUN-11 10:00:00 to 15-JUN-11 20:23:00 (CST-6)
Location: OSKALOOSA MUNI ARPT
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 100.00K
Reported by: Law Enforcement

Flash Flood in MAHASKA, IOWA
From 14-JUN-11 06:15:00 to 14-JUN-11 10:00:00 (CST-6)
Location: OSKALOOSA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 10.00K
Reported by: Department of Highways

Highway 92 closed from T25 to U.S. Highway 163 by flash flooding.

Hail in STORY, IOWA
From 14-JUN-11 01:17:00 to 14-JUN-11 01:17:00 (CST-6)
Location: MIDVALE
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Hail in STORY, IOWA
From 14-JUN-11 01:20:00 to 14-JUN-11 01:20:00 (CST-6)
Location: HUXLEY
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in STORY, IOWA
From 14-JUN-11 01:45:00 to 14-JUN-11 01:45:00 (CST-6)
Location: NEVADA
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Hail in DALLAS, IOWA
From 14-JUN-11 01:30:00 to 14-JUN-11 01:30:00 (CST-6)
Location: HADDEN HILL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Broadcast Media

Hail in UNION, IOWA
From 13-JUN-11 22:05:00 to 13-JUN-11 22:05:00 (CST-6)
Location: CRESTON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Hail in MADISON, IOWA
From 13-JUN-11 23:25:00 to 13-JUN-11 23:25:00 (CST-6)
Location: EARLHAM
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Hail in DALLAS, IOWA
From 13-JUN-11 23:55:00 to 13-JUN-11 23:55:00 (CST-6)
Location: ORTONVILLE
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: NWS Employee

Hail in MARION, IOWA
From 13-JUN-11 23:55:00 to 13-JUN-11 23:55:00 (CST-6)
Location: BUSSEY
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in STORY, IOWA
From 14-JUN-11 01:25:00 to 14-JUN-11 01:25:00 (CST-6)
Location: HUXLEY
Magnitude: 2.00 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in MARION, IOWA
From 14-JUN-11 04:00:00 to 14-JUN-11 04:00:00 (CST-6)
Location: PELLA MUNI ARPT
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in CERRO GORDO, IOWA
From 14-JUN-11 04:10:00 to 14-JUN-11 04:10:00 (CST-6)
Location: CENTRAL HGTS
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter