Supercell thunderstorms developed in the afternoon and evening north of a warm front that ran from Southern Iowa into Central Illinois.  Three distinct supercells produced a majority of the wind, hail, and heavy rain reports from Jefferson County Iowa into Henry County Illinois.  Mercer County Illinois was under tornado warnings on a continuous basis for 2 hours.  Officials at a high school track meet in Aledo, Illinois ushered all students into the safety of the school resulting in no injuries.  The training of the supercells from Louisa County Iowa to Henry County Illinois dumped heavy rain over the Edwards River and Pope Creek basins in Illinois with radar estimating 9 inches of rain.  Actual amounts varied due to large amounts of hail with the storms.  Cambridge Illinois estimated 7 to 8 inches of rain fell in the town.  Illinois Route 17 was closed due to flooding between Aledo and Viola with Illinois Route 94 closed south of Aledo.  In Andover Illinois, two thirds of the town had basements flooded.  Toward the end of the event a bow echo developed in Henry County Illinois and raced east across Bureau and Putnam counties.  The fire department in Standard, Illinois measured a 69 knot (80 mph) wind gust when the bow echo moved through.  In Clinton, Iowa, a lightning strike started a warehouse fire at the Nestle Purnina Complex.

Hail in MERCER, ILLINOIS
From 30-APR-03 18:01:00 to 30-APR-03 18:01:00 (CST)
Location: NEW BOSTON
Magnitude: 1.75 
Property damage: 500K
Reported by: EMERGENCY MANAGER

Tornado in MERCER, ILLINOIS
From 30-APR-03 18:11:00 to 30-APR-03 18:13:00 (CST)
Location: VIOLA
Tornado F-scale: F0
Property damage: 250K
Reported by: NWS STORM SURVEY

House damaged

Tornado in MERCER, ILLINOIS
From 30-APR-03 17:42:00 to 30-APR-03 17:42:00 (CST)
Location: ALEDO
Tornado F-scale: F1
Property damage: 500K
Reported by: LAW ENFORCEMENT

Damaged farm buildings

Hail in MERCER, ILLINOIS
From 30-APR-03 17:30:00 to 30-APR-03 17:30:00 (CST)
Location: JOY
Magnitude: 1.75 
Property damage: 350K
Reported by: EMERGENCY MANAGER

Tornado in MERCER, ILLINOIS
From 30-APR-03 17:57:00 to 30-APR-03 18:00:00 (CST)
Location: ALEDO
Tornado F-scale: F0
Property damage: 50K
Reported by: NWS STORM SURVEY

traveled through open country

Funnel Cloud in MERCER, ILLINOIS
From 30-APR-03 17:38:00 to 30-APR-03 17:38:00 (CST)
Location: ALEDO
Reported by: LAW ENFORCEMENT

Hail in MERCER, ILLINOIS
From 30-APR-03 19:04:00 to 30-APR-03 19:04:00 (CST)
Location: NEW WINDSOR
Magnitude: 1.75 
Property damage: 500K
Reported by: TRAINED SPOTTER

Heavy Rain in MERCER, ILLINOIS
From 30-APR-03 18:00:00 to 30-APR-03 21:00:00 (CST)
Location: NEW WINDSOR
Magnitude: 6 
Property damage: 150K
Reported by: TRAINED SPOTTER

Hail in MERCER, ILLINOIS
From 30-APR-03 17:12:00 to 30-APR-03 17:12:00 (CST)
Location: NEW BOSTON
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in MERCER, ILLINOIS
From 30-APR-03 17:25:00 to 30-APR-03 17:25:00 (CST)
Location: NEW BOSTON
Magnitude: 1.25 
Property damage: 150K
Reported by: EMERGENCY MANAGER

Hail in HENRY, ILLINOIS
From 30-APR-03 19:25:00 to 30-APR-03 19:25:00 (CST)
Location: GALVA
Magnitude: 1.00 
Property damage: 50K
Reported by: EMERGENCY MANAGER

Funnel Cloud in HENRY, ILLINOIS
From 30-APR-03 19:25:00 to 30-APR-03 19:25:00 (CST)
Location: KEWANEE
Reported by: AMATEUR RADIO

Hail in ROCK ISLAND, ILLINOIS
From 30-APR-03 19:46:00 to 30-APR-03 19:46:00 (CST)
Location: OAK GROVE
Magnitude: 1.75 
Property damage: 500K
Reported by: TRAINED SPOTTER

Flash Flood in HENRY, ILLINOIS
From 30-APR-03 20:30:00 to 30-APR-03 23:30:00 (CST)
Location: COUNTYWIDE
Magnitude: 7 
Property damage: 10M
Reported by: LAW ENFORCEMENT

Flash Flood in MERCER, ILLINOIS
From 30-APR-03 20:00:00 to 30-APR-03 23:30:00 (CST)
Location: COUNTYWIDE
Magnitude: 7 
Property damage: 10M
Reported by: LAW ENFORCEMENT

IL 94 and 17 closed

Hail in HENDERSON, ILLINOIS
From 30-APR-03 20:45:00 to 30-APR-03 20:45:00 (CST)
Location: OQUAWKA
Magnitude: 0.88 
Reported by: EMERGENCY MANAGER

Hail in HENRY, ILLINOIS
From 30-APR-03 19:05:00 to 30-APR-03 19:05:00 (CST)
Location: CAMBRIDGE
Magnitude: 1.00 
Property damage: 50K
Reported by: EMERGENCY MANAGER

Hail in MERCER, ILLINOIS
From 30-APR-03 18:18:00 to 30-APR-03 18:20:00 (CST)
Location: NEW WINDSOR
Magnitude: 1.75 
Property damage: 50K
Reported by: TRAINED SPOTTER

Hail in ROCK ISLAND, ILLINOIS
From 30-APR-03 19:35:00 to 30-APR-03 19:35:00 (CST)
Location: REYNOLDS
Magnitude: 1.00 
Property damage: 20K
Reported by: TRAINED SPOTTER

North side of Illinois 94

Hail in HENRY, ILLINOIS
From 30-APR-03 19:41:00 to 30-APR-03 19:41:00 (CST)
Location: KEWANEE
Magnitude: 1.00 
Property damage: 50K
Reported by: TRAINED SPOTTER

Hail in HENRY, ILLINOIS
From 30-APR-03 18:54:00 to 30-APR-03 18:54:00 (CST)
Location: ALPHA
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Covered the ground

Hail in HENRY, ILLINOIS
From 30-APR-03 19:44:00 to 30-APR-03 19:44:00 (CST)
Location: GALVA
Magnitude: 0.75 
Reported by: EMERGENCY MANAGER

Hail in BUREAU, ILLINOIS
From 30-APR-03 20:30:00 to 30-APR-03 21:30:00 (CST)
Location: COUNTYWIDE
Magnitude: 0.88 
Reported by: NEWSPAPER

Bow echo

Hail in HENRY, ILLINOIS
From 30-APR-03 21:08:00 to 30-APR-03 21:08:00 (CST)
Location: GALVA
Magnitude: 1.00 
Property damage: 50K
Reported by: EMERGENCY MANAGER

Tornado in MERCER, ILLINOIS
From 30-APR-03 18:12:00 to 30-APR-03 18:14:00 (CST)
Location: VIOLA
Tornado F-scale: F1
Property damage: 300K
Reported by: NWS STORM SURVEY

House pushed 6 feet off foundation

Hail in MERCER, ILLINOIS
From 30-APR-03 18:12:00 to 30-APR-03 18:12:00 (CST)
Location: NEW BOSTON
Magnitude: 1.75 
Property damage: 500K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in PUTNAM, ILLINOIS
From 30-APR-03 21:14:00 to 30-APR-03 21:14:00 (CST)
Location: PUTNAM
Magnitude: 52 EG
Property damage: 500K
Reported by: LAW ENFORCEMENT

Tree down & truck rolled over

Hail in MERCER, ILLINOIS
From 30-APR-03 18:25:00 to 30-APR-03 18:25:00 (CST)
Location: MATHERVILLE
Magnitude: 0.75 
Reported by: AMATEUR RADIO

Hail in MERCER, ILLINOIS
From 30-APR-03 19:45:00 to 30-APR-03 19:45:00 (CST)
Location: MATHERVILLE
Magnitude: 1.75 
Property damage: 500K
Reported by: EMERGENCY MANAGER

Hail in BUREAU, ILLINOIS
From 30-APR-03 20:43:00 to 30-APR-03 20:43:00 (CST)
Location: PRINCETON
Magnitude: 1.00 
Property damage: 50K
Reported by: EMERGENCY MANAGER

Tornado in HENRY, ILLINOIS
From 30-APR-03 18:29:00 to 30-APR-03 18:29:00 (CST)
Location: ALPHA
Tornado F-scale: F0
Reported by: LAW ENFORCEMENT

Touched down in field

Funnel Cloud in HENRY, ILLINOIS
From 30-APR-03 19:40:00 to 30-APR-03 19:40:00 (CST)
Location: GALVA
Reported by: AMATEUR RADIO

Thunderstorm Wind in HENRY, ILLINOIS
From 30-APR-03 20:28:00 to 30-APR-03 20:28:00 (CST)
Location: ANNAWAN
Magnitude: 70 EG
Property damage: 400K
Reported by: NEWSPAPER

Barn destroyed & house damaged

Flash Flood in HENRY, ILLINOIS
From 30-APR-03 20:00:00 to 30-APR-03 23:00:00 (CST)
Location: KEWANEE
Magnitude: 7 
Property damage: 250K
Reported by: TRAINED SPOTTER

6 inches water over roads

Hail in MERCER, ILLINOIS
From 30-APR-03 20:55:00 to 30-APR-03 20:55:00 (CST)
Location: NEW WINDSOR
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in HENRY, ILLINOIS
From 30-APR-03 19:32:00 to 30-APR-03 19:32:00 (CST)
Location: GALVA
Magnitude: 1.75 
Property damage: 500K
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in PUTNAM, ILLINOIS
From 30-APR-03 21:00:00 to 30-APR-03 21:20:00 (CST)
Location: PUTNAM
Magnitude: 61 EG
Property damage: 3M
Reported by: NWS STORM SURVEY

Bow echo

Hail in BUREAU, ILLINOIS
From 30-APR-03 20:55:00 to 30-APR-03 20:55:00 (CST)
Location: WYANET
Magnitude: 0.75 
Reported by: EMERGENCY MANAGER

Thunderstorm Wind in PUTNAM, ILLINOIS
From 30-APR-03 21:20:00 to 30-APR-03 21:20:00 (CST)
Location: STANDARD
Magnitude: 69.2 MG
Property damage: 1M
Reported by: FIRE DEPT/RESCUE SQUAD

Flash Flood in HENRY, ILLINOIS
From 30-APR-03 20:00:00 to 30-APR-03 23:30:00 (CST)
Location: GALVA
Magnitude: 6 
Property damage: 250K
Reported by: EMERGENCY MANAGER

IL 17 & US 34 flooded

Thunderstorm Wind in BUREAU, ILLINOIS
From 30-APR-03 20:23:00 to 30-APR-03 20:23:00 (CST)
Location: PROVIDENCE
Magnitude: 61 EG
Property damage: 150K
Reported by: EMERGENCY MANAGER

32 x 48 foot barn destroyed

Tornado in MERCER, ILLINOIS
From 30-APR-03 18:08:00 to 30-APR-03 18:09:00 (CST)
Location: VIOLA
Tornado F-scale: F1
Property damage: 500K
Reported by: NWS STORM SURVEY

Farm house damaged