A strong frontal boundary was stretched across Iowa.  At the same time a 35 kt low level jet pushed warm and humid air into the frontal boundary.  There was a reasonable amount of elevated instability with 1000 to 1500 J/kg available.  The atmosphere was strongly sheared with 50 to 80 kts of effective shear available.  Though the CAPE in the -10 to -30 C layer of the atmosphere was not all that high, it was in the 200 to 400 J/kg range.  Precipitable water values were greater than 2 sigma above normal, in the 1 to 1.25 inch range.  A broad southwest flow was present over the region with a closed upper low over the southwest U.S. A short wave lifted northeast and interacted with the frontal boundary during the morning.  An MCS formed, producing heavy rainfall and hail of nickle to quarter size in parts of central into northeast Iowa.  The largest hail fell near Stratford in Hamilton County.  It was half dollar in size.  Several areas received 1 to 2 inches of rain in the 24 hour period ending the morning of the 9th.  The heaviest was in Webster County near Stratford with 3.73 inches.

Hail in WEBSTER, IOWA
From 09-APR-13 07:15:00 to 09-APR-13 07:16:00 (CST-6)
Location: DUNCOMBE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HAMILTON, IOWA
From 09-APR-13 06:58:00 to 09-APR-13 06:58:00 (CST-6)
Location: STRATFORD
Magnitude: 1.25 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Public

Hail was up to half dollar size.

Hail in GRUNDY, IOWA
From 09-APR-13 08:14:00 to 09-APR-13 08:14:00 (CST-6)
Location: DIKE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in GRUNDY, IOWA
From 09-APR-13 08:19:00 to 09-APR-13 08:19:00 (CST-6)
Location: FREDSVILLE
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Hail in BREMER, IOWA
From 09-APR-13 08:40:00 to 09-APR-13 08:40:00 (CST-6)
Location: DENVER
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Relayed by kcrg television.

Heavy Rain in GREENE, IOWA
From 09-APR-13 05:50:00 to 09-APR-13 05:50:00 (CST-6)
Location: JEFFERSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.53 inches.

Heavy Rain in HAMILTON, IOWA
From 09-APR-13 06:00:00 to 09-APR-13 06:00:00 (CST-6)
Location: JEWELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.02 inches.

Heavy Rain in RINGGOLD, IOWA
From 09-APR-13 05:50:00 to 09-APR-13 05:50:00 (CST-6)
Location: BEACONSFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 2.68 inches.

Heavy Rain in HUMBOLDT, IOWA
From 09-APR-13 06:00:00 to 09-APR-13 06:00:00 (CST-6)
Location: BODE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.88 inches.

Heavy Rain in WARREN, IOWA
From 09-APR-13 06:15:00 to 09-APR-13 06:15:00 (CST-6)
Location: INDIANOLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.33 inches.

Heavy Rain in GRUNDY, IOWA
From 09-APR-13 06:35:00 to 09-APR-13 06:35:00 (CST-6)
Location: GRUNDY CENTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.54 inches.

Heavy Rain in GRUNDY, IOWA
From 09-APR-13 06:50:00 to 09-APR-13 06:50:00 (CST-6)
Location: CONRAD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.97 inches.

Heavy Rain in GUTHRIE, IOWA
From 09-APR-13 07:10:00 to 09-APR-13 07:10:00 (CST-6)
Location: GUTHRIE CENTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.35 inches.

Heavy Rain in POLK, IOWA
From 09-APR-13 07:00:00 to 09-APR-13 07:00:00 (CST-6)
Location: ALTOONA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Rainfall 1.83 inches.

Heavy Rain in POWESHIEK, IOWA
From 09-APR-13 07:30:00 to 09-APR-13 07:30:00 (CST-6)
Location: BROOKLYN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.26 inches.

Heavy Rain in HAMILTON, IOWA
From 09-APR-13 07:50:00 to 09-APR-13 07:50:00 (CST-6)
Location: WEBSTER CITY ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall 2.00 inches.

Heavy Rain in WEBSTER, IOWA
From 09-APR-13 10:09:00 to 09-APR-13 10:09:00 (CST-6)
Location: DAYTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall 3.73 inches in the past 24 hours.

Hail in RINGGOLD, IOWA
From 08-APR-13 22:20:00 to 08-APR-13 22:20:00 (CST-6)
Location: BEACONSFIELD
Magnitude: 1.00 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Public

Hail still in ditches the next morning. Siding of houses damaged and plastic on shed damaged with window screens also torn.

Heavy Rain in PALO ALTO, IOWA
From 09-APR-13 10:55:00 to 09-APR-13 10:55:00 (CST-6)
Location: EMMETSBURG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.10 inches.

Heavy Rain in CRAWFORD, IOWA
From 09-APR-13 10:00:00 to 09-APR-13 10:00:00 (CST-6)
Location: DENISON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall 1.18 inches.