A frontal boundary remained across the area on the 19th as a shortwave moved into the area and interacted with the front.  A low pressure wave formed on the front and lifted northeast across the state during the late afternoon.  As the front sagged south, a line of thunderstorms formed and moved east-southeast through Iowa.  The airmass became very unstable by late afternoon with CAPE in the 3000-4000 J/kg range and lifted indices in the -6 to -10 C range.  Surface dewpoints rose into the low to mid 70s ahead of the front with temperatures in the 80s.  The freezing level was quite high at around 15,000 feet and the CAPE in the -10 to -30 C. layer of the atmosphere was around 500 J/kg.  Unlike in previous days, there was moderate shear in the atmosphere with 35 to 45 kts.  Precipitable water was around 1.7 inches.  The LCL was relatively low, at around 750 meters.  The thunderstorms became severe quite rapidly and produced wind gusts to around 60 MPH.  Hail was limited in size by the warm and moist atmosphere.  Most of the hail was around three quarters of an inch or less, with the larger hail around an inch in diameter.  There there three tornadoes during the event.  The first touched down in Kossuth County, south of Algona, and did only minor damage with trees uprooted.  The second was in Carroll County from the Templeton area toward Coon Rapids.  This tornado caused more damage along its track.  On one farmstead, it hit the house and barn.  The barn was completely flattened, and damage was done to the house.  Power lines were also downed.  The main line of storms moved out of the state by around midnight.  During the night, as the low level jet strengthened, the front began lifting north again.  A scattered line of thunderstorms formed from west central into central Iowa.  One of the storms produced penny size hail in the Huxley area of Story County.

Thunderstorm Wind in HAMILTON, IOWA
From 19-JUL-08 17:55:00 to 19-JUL-08 17:55:00 (CST-6)
Location: WEBSTER CITY
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Ten to 15 inch tree branches down.

Thunderstorm Wind in WRIGHT, IOWA
From 19-JUL-08 17:49:00 to 19-JUL-08 17:49:00 (CST-6)
Location: BELMOND
Magnitude: 57.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous 12 inch diameter branches down.  Trees snapped in half.

Hail in POLK, IOWA
From 19-JUL-08 20:18:00 to 19-JUL-08 20:18:00 (CST-6)
Location: DES MOINES
Magnitude: 0.88 
Property damage: 1.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 19-JUL-08 20:28:00 to 19-JUL-08 20:28:00 (CST-6)
Location: WINDSOR HGTS
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in BLACK HAWK, IOWA
From 19-JUL-08 19:13:00 to 19-JUL-08 19:13:00 (CST-6)
Location: WATERLOO
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Report from the Waterloo RWIS site.

Thunderstorm Wind in CARROLL, IOWA
From 19-JUL-08 19:04:00 to 19-JUL-08 19:04:00 (CST-6)
Location: COON RAPIDS
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in KOSSUTH, IOWA
From 19-JUL-08 17:11:00 to 19-JUL-08 17:11:00 (CST-6)
Location: LU VERNE
Magnitude: 50.00 MG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured wind by the KCCI schoolnet site.

Thunderstorm Wind in KOSSUTH, IOWA
From 19-JUL-08 16:47:00 to 19-JUL-08 16:47:00 (CST-6)
Location: WHITTEMORE
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured at the Algona RWIS site on U.S. Highway 18.

Thunderstorm Wind in HANCOCK, IOWA
From 19-JUL-08 17:30:00 to 19-JUL-08 17:30:00 (CST-6)
Location: KANAWHA
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm Wind in HUMBOLDT, IOWA
From 19-JUL-08 17:15:00 to 19-JUL-08 17:15:00 (CST-6)
Location: LIVERMORE
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous large tree branches down along southern side of Lu Verne.

Hail in POLK, IOWA
From 19-JUL-08 20:45:00 to 19-JUL-08 20:45:00 (CST-6)
Location: DES MOINES
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Public

Hail in POLK, IOWA
From 19-JUL-08 20:26:00 to 19-JUL-08 20:26:00 (CST-6)
Location: URBANDALE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Report from the intersection of Merle Hay Road and Douglas.

Hail in CARROLL, IOWA
From 19-JUL-08 19:04:00 to 19-JUL-08 19:04:00 (CST-6)
Location: COON RAPIDS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Tornado in KOSSUTH, IOWA
From 19-JUL-08 17:00:00 to 19-JUL-08 17:01:00 (CST-6)
Location: IRVINGTON
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 1.00K
Reported by: Law Enforcement

A brief tornado touchdown was reported with numerous trees uprooted.

Tornado in MARSHALL, IOWA
From 19-JUL-08 19:10:00 to 19-JUL-08 19:11:00 (CST-6)
Location: MARSHALLTOWN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A brief touchdown was reported with no damage.

Tornado in CARROLL, IOWA
From 19-JUL-08 18:39:00 to 19-JUL-08 18:58:00 (CST-6)
Location: TEMPLETON
Tornado F-scale: EF1
Property damage: 150.00K
Crop damage: 500.00K
Reported by: Trained Spotter

Tornado touched down near the intersection of Highway 141 and Hawthorne.  A farmstead was hit along the path, flattening the barn and damaging the homestead.  Power lines were also downed by the tornado.

Thunderstorm Wind in POLK, IOWA
From 19-JUL-08 21:01:00 to 19-JUL-08 21:01:00 (CST-6)
Location: DES MOINES
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Wind gust measured at the Des Moines International Airport.

Thunderstorm Wind in BLACK HAWK, IOWA
From 19-JUL-08 19:22:00 to 19-JUL-08 19:22:00 (CST-6)
Location: EVANSDALE
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Hail in STORY, IOWA
From 20-JUL-08 01:58:00 to 20-JUL-08 01:58:00 (CST-6)
Location: HUXLEY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 10.00K
Reported by: Law Enforcement