A cold front slowly moved southeast into eastern Iowa during the daytime hours of August 4.  South to southwest winds brought increased heat and humidity with high temperatures that ranged from 82 at Freeport, IL to 99 at Muscatine, IA.  Heat index readings were as high as 120 degrees.
Late that afternoon and evening, an upper level disturbance moved along the cold front triggering showers and thunderstorms over northeast Iowa and northwest Illinois.  Some of the storms produced brief heavy rains, large hail, and damaging winds, with one storm in particular developing a tornado between Charlotte, IA and Goose Lake, IA.

Thunderstorm Wind in JONES, IOWA
From 04-AUG-08 15:55:00 to 04-AUG-08 15:55:00 (CST-6)
Location: MONTICELLO
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts estimated to be 60 mph were observed in Monticello, IA at 455 pm August 4.

Hail in JONES, IOWA
From 04-AUG-08 16:15:00 to 04-AUG-08 16:15:00 (CST-6)
Location: TEMPLE HILL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Nickel-sized hail fell 1 mile west southwest of Cascade, IA at 515 pm August 4.

Thunderstorm Wind in DUBUQUE, IOWA
From 04-AUG-08 16:20:00 to 04-AUG-08 16:20:00 (CST-6)
Location: SAGEVILLE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts estimated to be 60 mph blew down several small trees and branches across the north side of Dubuque, IA at 520 pm August 4.

Hail in DELAWARE, IOWA
From 04-AUG-08 15:55:00 to 04-AUG-08 15:55:00 (CST-6)
Location: HOPKINTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Dime to quarter-sized hail fell in Hopkinton, IA at 455 pm August 4.

Hail in DUBUQUE, IOWA
From 04-AUG-08 16:50:00 to 04-AUG-08 16:50:00 (CST-6)
Location: CASCADE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Nickel-sized hail fell in Cascade, IA around 550 pm August 4.

Thunderstorm Wind in CLINTON, IOWA
From 04-AUG-08 17:08:00 to 04-AUG-08 17:08:00 (CST-6)
Location: CLINTON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts estimated to be 60 mph were observed on the north side of Clinton, IA along Highway 67 at 608 pm August 4.

Thunderstorm Wind in JACKSON, IOWA
From 04-AUG-08 16:52:00 to 04-AUG-08 16:52:00 (CST-6)
Location: BRIDGEPORT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts estimated to be 60 mph were observed 4 miles east southeast of Maquoketa, IA at 552 pm August 4.

Thunderstorm Wind in JACKSON, IOWA
From 04-AUG-08 16:55:00 to 04-AUG-08 16:55:00 (CST-6)
Location: MILES
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts estimated to be 70 mph were observed in Miles, IA at 555 pm August 4.

Thunderstorm Wind in CLINTON, IOWA
From 04-AUG-08 17:00:00 to 04-AUG-08 17:00:00 (CST-6)
Location: GOOSE LAKE
Magnitude: 66.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 76 mph wind gust blew down some trees in Goose Lake, IA around 600 pm August 4.  This report was relayed by a broadcast media partner.

Thunderstorm Wind in JACKSON, IOWA
From 04-AUG-08 16:33:00 to 04-AUG-08 16:33:00 (CST-6)
Location: COTTONVILLE
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Wind gusts estimated to be 75 mph blew down several large trees along a path from the Cottonville, IA area eastward towards the southern parts of the Bellevue, IA area around 533 pm August 4.

Thunderstorm Wind in JACKSON, IOWA
From 04-AUG-08 16:42:00 to 04-AUG-08 16:42:00 (CST-6)
Location: BELLEVUE
Magnitude: 65.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Wind gusts estimated to be 75 mph blew down at least 20 large trees in the Kurth Addition about a half of a mile south of Bellevue, IA at 542 pm August 4.  Power lines were also down.

Tornado in CLINTON, IOWA
From 04-AUG-08 16:47:00 to 04-AUG-08 17:05:00 (CST-6)
Location: CHARLOTTE
Tornado F-scale: EF0
Property damage: 250.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An EF0 tornado damaged three farmsteads along a path from 3.2 miles north northeast of Charlotte, IA to 4 miles south southwest of Goose Lake, IA between 547 pm and 605 pm August 4.  Several outbuildings were damaged with the total loss of the roofing on many of them.  Many trees and branches were damaged, with several large trees blown down or snapped off.