A cold front settled south into the Des Moines CWA during the predawn hours of the 29th.  Severe parameters were relatively weak with limited moisture available.  Precipitable water was around a half inch with surface dewpoints around 50.  The elevated CAPE was only around 400 J/kg with 30 to 40 kts of shear.  The freezing level was relatively low, around 10,300 feet.  Though there was around 1100 J/kg of downdraft CAPE available, a strong inversion was in place due to the hour of the day.  Thunderstorms formed shortly before sunrise along the cold front.  The storms continued to develop during the morning hours as the front retreated back to the north.  They produced significant amounts of hail, mostly over the far northeast and parts of the north central sections of the Des Moines CWA.  Hail up to 2 inches in diameter fell near Waterloo in Black Hawk County.  Most of the hail was quarter to half dollar size.  There were several reports of hail covering the ground, in some places two to three inches deep.

Hail in WEBSTER, IOWA
From 29-APR-13 04:20:00 to 29-APR-13 04:20:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported hail a little larger than quarters.

Hail in GRUNDY, IOWA
From 29-APR-13 07:32:00 to 29-APR-13 07:32:00 (CST-6)
Location: FERN
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Quarter size hail covering the ground.

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:20:00 to 29-APR-13 08:20:00 (CST-6)
Location: CASTLE HILL
Magnitude: 1.00 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail covering the ground at the intersection of Greenhill Road and Rainbow Drive.
Relayed by KCVM.

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:30:00 to 29-APR-13 08:30:00 (CST-6)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hall covering the ground two the three inches deep at the intersection of Conger St and Highway 63.

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:30:00 to 29-APR-13 08:30:00 (CST-6)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HARDIN, IOWA
From 29-APR-13 06:38:00 to 29-APR-13 06:38:00 (CST-6)
Location: ABBOTT
Magnitude: 1.00 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

An Iowa State Trooper reported quarter size hail on the highway two inches deep.

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:19:00 to 29-APR-13 08:19:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 1.00 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Hail in GRUNDY, IOWA
From 29-APR-13 06:48:00 to 29-APR-13 06:48:00 (CST-6)
Location: WELLSBURG
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Dime to nickel size hail covering a two mile stretch of T-19 north of Wellsburg.  Hail was 2 inches deep.

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:30:00 to 29-APR-13 08:30:00 (CST-6)
Location: WATERLOO
Magnitude: 1.25 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Public

Quarter to half dollar size hail.

Hail in GRUNDY, IOWA
From 29-APR-13 07:30:00 to 29-APR-13 07:30:00 (CST-6)
Location: FERN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:23:00 to 29-APR-13 08:23:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 1.25 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:25:00 to 29-APR-13 08:25:00 (CST-6)
Location: WATERLOO
Magnitude: 2.00 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:25:00 to 29-APR-13 08:25:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 1.25 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:21:00 to 29-APR-13 08:21:00 (CST-6)
Location: CEDAR FALLS
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:35:00 to 29-APR-13 08:35:00 (CST-6)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in BLACK HAWK, IOWA
From 29-APR-13 08:30:00 to 29-APR-13 08:30:00 (CST-6)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

One inch wide by one half inch thick hail measured by KWWL.