A complicated weather situation unfolded during the day on the 14th into the evening.  A mesoscale convective system moved through the state during the previous night and left a considerable amount of debris cloudiness during the afternoon of the 14th.  In addition, a cap developed over the state during the afternoon.  A cold front approached Iowa from the northwest and had entered the northwest part of the state by evening.  The atmosphere became unstable during the late afternoon hours with most unstable CAPE near 4000 J/kg and lifted indices in the -9 to -12 C range.  There was considerable downdraft CAPE available, in excess of 1000 J/kg.  The CAPE in the -10 to -30 C layer of the atmosphere was in the 1000 to 1400 J/kg range by evening.  Shear values were in the 30 kt range initially.  Thunderstorms were slow to develop, but did eventually develop just ahead of the cold front in northwest Iowa.  A broken squall line developed by the early evening hours, and translated southeast into the state.  The primary mode of severe weather with this event was in the form of hail in spite of the freezing level approaching 15,000 feet.  Spotty wind reports of around 60 MPH wind were received in north central and parts of central Iowa.  The storms produced hail in many locations.  For the most part, the hail was on the order of an inch or so in diameter.  The storms moved through Polk County shortly before midnight and produced very large hail.  Hail up to 3 inches in diameter was reported to the north and east of Johnston.  Considerable damage was done to cars with damaged wind shields and denting.  Damage also occurred to roofs.

Hail in POLK, IOWA
From 14-JUL-09 23:08:00 to 14-JUL-09 23:08:00 (CST-6)
Location: JOHNSTON
Magnitude: 3.00 
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in POLK, IOWA
From 14-JUL-09 22:56:00 to 14-JUL-09 23:03:00 (CST-6)
Location: GRIMES
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 15.00K
Reported by: CoCoRaHS

Hail in EMMET, IOWA
From 14-JUL-09 18:59:00 to 14-JUL-09 18:59:00 (CST-6)
Location: RALEIGH
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in CLARKE, IOWA
From 14-JUL-09 22:38:00 to 14-JUL-09 22:38:00 (CST-6)
Location: MURRAY
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in WINNEBAGO, IOWA
From 14-JUL-09 20:15:00 to 14-JUL-09 20:15:00 (CST-6)
Location: NEILS
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Hail in EMMET, IOWA
From 14-JUL-09 19:00:00 to 14-JUL-09 19:10:00 (CST-6)
Location: ESTHERVILLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 50.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 14-JUL-09 22:56:00 to 14-JUL-09 23:05:00 (CST-6)
Location: JOHNSTON
Magnitude: 1.25 
Property damage: 10.00K
Crop damage: 5.00K
Reported by: Official NWS Observations

Hail in POLK, IOWA
From 14-JUL-09 23:15:00 to 14-JUL-09 23:15:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 1.00 
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

Public reported hail up to quarter size on the east side of Des Moines near Capitol Heights.

Heavy Rain in EMMET, IOWA
From 14-JUL-09 19:00:00 to 14-JUL-09 19:00:00 (CST-6)
Location: ESTHERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported very heavy rain with minor flooding in and around Estherville.  Several inches of water on some roads along with penny size hail.

Hail in POLK, IOWA
From 14-JUL-09 23:03:00 to 14-JUL-09 23:03:00 (CST-6)
Location: POLK CITY
Magnitude: 1.25 
Property damage: 3.00K
Crop damage: 3.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 14-JUL-09 22:59:00 to 14-JUL-09 22:59:00 (CST-6)
Location: HERROLD
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 14-JUL-09 23:01:00 to 14-JUL-09 23:01:00 (CST-6)
Location: RIDER
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 14-JUL-09 23:04:00 to 14-JUL-09 23:04:00 (CST-6)
Location: JOHNSTON
Magnitude: 2.00 
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Windows were broken out due to large hail at an apartment complex.

Hail in POLK, IOWA
From 14-JUL-09 22:59:00 to 14-JUL-09 22:59:00 (CST-6)
Location: HERROLD
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail was reported at the intersection of NW Oaktree Drive and Timberbrooke lane.

Hail in POLK, IOWA
From 14-JUL-09 23:00:00 to 14-JUL-09 23:00:00 (CST-6)
Location: JOHNSTON
Magnitude: 3.00 
Property damage: 100.00K
Crop damage: 20.00K
Reported by: Amateur Radio

The hail measured 2.25 inches by 3 inches.

Hail in POLK, IOWA
From 14-JUL-09 23:11:00 to 14-JUL-09 23:11:00 (CST-6)
Location: SAYLORVILLE
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 15.00K
Reported by: Trained Spotter

Hail reported at the intersecton of Oralabor and State Street.

Hail in POLK, IOWA
From 14-JUL-09 23:10:00 to 14-JUL-09 23:10:00 (CST-6)
Location: CARNEY
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Public

Public reports hail measuring 1.5 to 1.75 inches about one half mile south of DMACC in Ankeny.

Thunderstorm Wind in MARION, IOWA
From 14-JUL-09 23:25:00 to 14-JUL-09 23:25:00 (CST-6)
Location: BUSSEY
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Power lines were down east of Bussey near the Mahaska County Border.

Thunderstorm Wind in MAHASKA, IOWA
From 15-JUL-09 00:48:00 to 15-JUL-09 00:48:00 (CST-6)
Location: LAKONTA
Magnitude: 61.00 EG
Property damage: 50.00K
Crop damage: 5.00K
Reported by: Trained Spotter

The wind blew over an 8 X 8 unanchored metal shed.  Estimated 12 inch diameter tree branches were down and power poles were bent over.

Hail in POLK, IOWA
From 14-JUL-09 23:18:00 to 14-JUL-09 23:18:00 (CST-6)
Location: CAPITOL HGTS
Magnitude: 1.00 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail reported at east 25th St and Mansfield on the east side of Des Moines.

Thunderstorm Wind in CERRO GORDO, IOWA
From 14-JUL-09 20:50:00 to 14-JUL-09 20:50:00 (CST-6)
Location: CLEAR LAKE
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported 7 inch diameter branches down at 7th St and Main Ave in Clear Lake.

Thunderstorm Wind in MARION, IOWA
From 14-JUL-09 23:10:00 to 14-JUL-09 23:10:00 (CST-6)
Location: KNOXVILLE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Power lines were down just west of Knoxville.

Thunderstorm Wind in CERRO GORDO, IOWA
From 14-JUL-09 20:48:00 to 14-JUL-09 20:48:00 (CST-6)
Location: CLEAR LAKE
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Ten inch diameter branches were downed.

Thunderstorm Wind in DALLAS, IOWA
From 14-JUL-09 22:43:00 to 14-JUL-09 22:43:00 (CST-6)
Location: MINBURN
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Power poles were down, along with a one foot diameter tree.

Hail in POLK, IOWA
From 14-JUL-09 23:17:00 to 14-JUL-09 23:17:00 (CST-6)
Location: DES MOINES
Magnitude: 1.75 
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail reported at the intersection of 2nd Ave and Euclid in the Highland Park area.