Supercell thunderstorms developed in the evening hours and formed an organized cluster around Waterloo, Iowa.  As the storms moved southeast through Eastern Iowa they interacted with boundaries and produced 6 tornadoes with widespread wind damage in the Cedar Rapids metropolitan area.  KCRG TV and KGAN TV in Cedar Rapids measured 63 knots (73 mph) and 53 knots (61 mph) respectively at their studios during the storm.  At the height of the storm in Cedar Rapids, Alliant Energy reported that about half of its 70,000 customers in the Cedar Rapids area were without power.  Sporatic wind damage then occurred from Cedar Rapids to the Mississippi River.  Heavy rain accompanying the storms produced mainly nuisance street flooding in many cities but did result in 2 mudslides, one in Moline, Illinois and another across Illinois 84 just northwest of Mississippi Palisades State Park in Carroll County Illinois.  The second mudslide resulted in a traffic accident with no injuries.  In Muscatine County the storms evolved into a bow echo and then raced East Southeast and produced widespread wind damage with winds estimated at 80 knots or stronger (92 mph) that lasted 10 to 15 minutes across the Illinois Counties of Rock Island, Mercer, and Southern Henry.  An unsubstantiated wind gust of 90 knots (104 mph) occurred at Lock and Dam 16 on the Mississippi River just east of Muscatine, Iowa.  Mercer and Southern Henry counties in Illinois had extensive damage from the bow echo with Galva, Illinois, in southern Henry County  being hardest hit.  An estimated 10,000 to 15,000 people were without power in the affected 3 counties.  High winds of at least 80 knots (92 mph) lasted for nearly 15 minutes in Galva, toppling a grain elevator onto the BNSF railroad mainline.  The combination of the toppled grain elevator and a propane leak caused by the fallen elevator halted rail traffic for 11 hours, delaying 7 or 8 BNSF trains.  Blackhawk College East Campus in Southeast Henry County cancelled classes for several days due to considerable damage with many trees and power lines down.  In Henry County Illinois alone, an estimated 25,000 acres of corn was flattened.

Thunderstorm Wind in LINN, IOWA
From 20-JUL-03 21:58:00 to 20-JUL-03 22:17:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 63 MG
Property damage: 5M
Reported by: BROADCAST MEDIA

Thunderstorm Wind in LINN, IOWA
From 20-JUL-03 21:40:00 to 20-JUL-03 21:50:00 (CST)
Location: PALO
Magnitude: 61 EG
Property damage: 250K
Crop damage: 30K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in LINN, IOWA
From 20-JUL-03 21:45:00 to 20-JUL-03 21:48:00 (CST)
Location: CENTER PT
Magnitude: 61 EG
Property damage: 250K
Crop damage: 30K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in JOHNSON, IOWA
From 20-JUL-03 22:45:00 to 20-JUL-03 22:53:00 (CST)
Location: CORALVILLE
Magnitude: 52 EG
Property damage: 2K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Heavy rain for 8 minutes

Thunderstorm Wind in JOHNSON, IOWA
From 20-JUL-03 22:52:00 to 20-JUL-03 23:04:00 (CST)
Location: IOWA CITY
Magnitude: 52 EG
Property damage: 30K
Reported by: TRAINED SPOTTER

KIOW measured 49 knots @ 2301 CST

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:00:00 to 20-JUL-03 23:10:00 (CST)
Location: ATALISSA
Magnitude: 56 EG
Property damage: 25K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Trees and power lines down

Heavy Rain in SCOTT, IOWA
From 20-JUL-03 23:00:00 to 20-JUL-03 23:59:00 (CST)
Location: DAVENPORT
Magnitude: 2.1 
Property damage: 2K
Reported by: TRAINED SPOTTER

Street flooding downtown

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:07:00 to 20-JUL-03 23:15:00 (CST)
Location: ATALISSA
Magnitude: 61 EG
Property damage: 15K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

6 power poles down

Heavy Rain in MUSCATINE, IOWA
From 20-JUL-03 23:10:00 to 20-JUL-03 23:32:00 (CST)
Location: MUSCATINE
Magnitude: 1 
Property damage: 2K
Reported by: TRAINED SPOTTER

In 22 minutes

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:15:00 to 20-JUL-03 23:25:00 (CST)
Location: ATALISSA
Magnitude: 56 EG
Property damage: 50K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Tree down on a 35 foot camper

Hail in MUSCATINE, IOWA
From 20-JUL-03 23:16:00 to 20-JUL-03 23:26:00 (CST)
Location: MUSCATINE
Magnitude: 1.00 
Property damage: 50K
Crop damage: 10K
Reported by: TRAINED SPOTTER

Lasted 10 minutes

Flash Flood in MUSCATINE, IOWA
From 20-JUL-03 23:20:00 to 21-JUL-03 01:00:00 (CST)
Location: MUSCATINE
Magnitude: 1.5 
Property damage: 10K
Reported by: TRAINED SPOTTER

Water bumper deep at Cedar and Mulberry Streets

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:20:00 to 20-JUL-03 23:30:00 (CST)
Location: MUSCATINE
Magnitude: 61 EG
Property damage: 20K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Tree down on a trailer

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:24:00 to 20-JUL-03 23:34:00 (CST)
Location: MUSCATINE MUNI ARPT
Magnitude: 50 MG
Property damage: 20K
Crop damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

KMUT AWOS

Thunderstorm Wind in MUSCATINE, IOWA
From 20-JUL-03 23:24:00 to 20-JUL-03 23:34:00 (CST)
Location: MUSCATINE
Magnitude: 52 EG
Property damage: 20K
Reported by: TRAINED SPOTTER

Trees down on U.S. 61

Heavy Rain in LINN, IOWA
From 20-JUL-03 22:00:00 to 20-JUL-03 22:40:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 1.5 
Property damage: 5K
Reported by: TRAINED SPOTTER

Interstate 380 and other streets partially flooded in spots

Funnel Cloud in LINN, IOWA
From 20-JUL-03 22:08:00 to 20-JUL-03 22:11:00 (CST)
Location: CEDAR RAPIDS
Reported by: BROADCAST MEDIA

Jct of Iowa 13 & 100 by KGAN TV

Funnel Cloud in LINN, IOWA
From 20-JUL-03 22:13:00 to 20-JUL-03 22:18:00 (CST)
Location: CEDAR RAPIDS
Reported by: BROADCAST MEDIA

Over KCRG downtown studio

Thunderstorm Wind in CEDAR, IOWA
From 20-JUL-03 22:33:00 to 20-JUL-03 22:43:00 (CST)
Location: LOWDEN
Magnitude: 61 EG
Property damage: 100K
Crop damage: 30K
Reported by: TRAINED SPOTTER

Corn flattened with trees down and an out building damaged

Heavy Rain in JOHNSON, IOWA
From 20-JUL-03 22:40:00 to 20-JUL-03 23:10:00 (CST)
Location: IOWA CITY
Magnitude: 1.5 
Property damage: 2K
Reported by: TRAINED SPOTTER

Dubuque street at I-80 with street flooding