A strong cold front moved through region. With plenty of moisture, instability and decent low level shear, severe storms developed along the Interstate 70 corridor in Missouri and Illinois.  Numerous reports of large hail and 5 tornadoes occurred with this event.  One of the tornadoes was a long track one that moved through the St. Louis metropolitan area with it being rated an EF4, with only a few minor injuries and no deaths. Also, quite a bit of rain fell during this event and caused flash flooding.  The flash flooding persisted for several days as additional rounds of heavy rain fell over the same region through the 26th of April.

Tornado in MADISON, ILLINOIS
From 22-APR-11 19:24:00 to 22-APR-11 19:31:00 (CST-6)
Location: GRANITE CITY
Tornado F-scale: EF2
Crop damage: 0.00K
Reported by: NWS Storm Survey

During the evening of Friday April 22nd, an intense supercell thunderstorm produced a long-track tornado which tore a path of destruction from west to east across the St. Louis Metropolitan Area, from St. Louis County Missouri eastward through the far northern portions of the City of St. Louis, then across the Mississippi River into Madison County Illinois. The tornado reached a maximum intensity of EF4 on the Enhanced Fujita Scale as it tracked through the community of Bridgeton, just west of Lambert St. Louis International Airport, in St. Louis County. The total path length was 21.3 miles, with a width of up to half a mile.
The tornado crossed the Mississippi River from the far northern portions of the City of St. Louis into Madison County Illinois approximately 1.5 miles south of Interstate 270 . The tornado continued east to half a mile north of the intersection of Illinois Route 203 and Pontoon Road. Damage east of this intersection included uprooted and snapped trees and three homes had roofs removed. At least one hundred homes were damaged in the area. The maximum damage found was in a neighborhood along Bern and Dawn Avenues. The tornadic damage then curved southeast and ended near the intersection of Alton Street and Pontoon Road. Damage width over this area varied from 50 to 150 yards with a path length of 5.1 miles.  The damage east of Illinois Route 203 was rated low-end EF2. The highest wind speeds associated with the EF2 damage were approximately 120 mph.

Tornado in ST. CLAIR, ILLINOIS
From 22-APR-11 20:02:00 to 22-APR-11 20:06:00 (CST-6)
Location: PADERBORN
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down half a mile northeast of Paderborn in southwestern St. Clair County and moved east southeastward towards the Sportsman Lake Subdivision. Two power poles were snapped on Knab Road while six homes at the lake sustained minor roof damage in which 30 to 40 percent of the shingles were removed. A number of medium to large trees were uprooted or snapped along the damage track in this subdivision.  The tornado lifted and dissipated on the far south side of the subdivision near Live Oak Drive.  The maximum intensity was EF1, with a maximum estimated wind speed of 100 mph.  The maximum width of the tornado was 60 to 80 yards and the total path length was 1.75 miles.

Hail in MONROE, ILLINOIS
From 22-APR-11 19:41:00 to 22-APR-11 19:41:00 (CST-6)
Location: COLUMBIA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MACOUPIN, ILLINOIS
From 22-APR-11 18:36:00 to 22-APR-11 18:36:00 (CST-6)
Location: SHIPMAN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Tornado in MONROE, ILLINOIS
From 22-APR-11 19:50:00 to 22-APR-11 19:55:00 (CST-6)
Location: WATERLOO
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down on the north side of Waterloo, Illinois near the intersection of Leah Drive and James Street.  Several homes and businesses sustained varying degrees of damage; from displaced roofing materials to businesses with structural damage. Two large air conditioners were tossed 30 yards from the roof of a business.  Several large trees were snapped near the base of the trunk. Four power poles were snapped south of the intersection of North Market Street and Kolmer Avenue.  One large garage was also destroyed behind a church with debris tossed southeastward 30 to 40 yards.  The tornado skipped eastward and crossed Floraville Road on the north side of Ridge Club Golf Course then traveled down the first fairway. A number of cedar and pine trees were snapped. The tornado then crossed Ridge Road where several homes sustained minor roof damage, with 30 to 40 percent of the shingles removed. The tornado then traveled across the northern part of Konarcik Park. Numerous old growth pine trees were snapped at the base of the trunk. Trees three feet in diameter were common in this area. The tornado caused damage to the siding of one home near the intersection of Konarcik and Kopp Roads before lifting.  There was one minor injury at Canterbury Manor Nursing Center due to flying glass when a window broke.  The maximum intensity was low end EF2, with a maximum estimated wind speed of 115 mph.  The maximum width of the tornado was 80 to 90 yards with a total path length of 3.5 miles.

Hail in ST. CLAIR, ILLINOIS
From 22-APR-11 20:05:00 to 22-APR-11 20:05:00 (CST-6)
Location: SMITHTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in CLINTON, ILLINOIS
From 22-APR-11 20:10:00 to 22-APR-11 20:16:00 (CST-6)
Location: ST ROSE
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado crossed from Madison County into Clinton County along Baumann Road.  It continued to produce damage to farm outbuildings and minor roof damage to homes. On Keyesport Road, the tornado reached its maximum intensity between Baumann Road and Watertower Road. A farm house was destroyed when it lost its entire roof structure and the front wall partially collapsed. The rest of the farm had six buildings that were either destroyed or severely damaged. A hog farm also suffered extensive damage farther to the east on Keyesport Road. The tornado then turned east northeast and crossed into Bond County.  The maximum intensity for this segment was rated EF2 and was on the ground for 3.1 miles before crossing into Bond County.  The maximum width of damage was 500 yards. As for the entire tornado, it was rated EF2, with maximum wind speeds of 130 mph.  The maximum width of the tornado was 700 yards and the total length of the tornado was 18.2 miles.

Tornado in BOND, ILLINOIS
From 22-APR-11 20:16:00 to 22-APR-11 20:30:00 (CST-6)
Location: BADEN BADEN
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado crossed from Clinton County into Bond County where it continued to snap and uproot trees, severely damage outbuildings and cause minor roof damage to homes before it finally dissipated around 930 pm about 7 miles south of Greenville. The maximum intensity for this segment was rated EF1 and was on the ground for 8.6 miles before lifting and dissipating.  The maximum width of damage was 500 yards. As for the entire tornado, it was rated EF2, with maximum wind speeds of 130 mph.  The maximum width of the tornado was 700 yards and the total length of the tornado was 18.2 miles.

Flash Flood in MONROE, ILLINOIS
From 22-APR-11 20:20:00 to 23-APR-11 00:30:00 (CST-6)
Location: COLUMBIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Up to three inches of rain fell in a short amount of time causing flash flooding.  Several roads had water over them including Bluff Road near intersection with Trout Road.  Several streets in Waterloo had 5 inches of water over them.

Flash Flood in ST. CLAIR, ILLINOIS
From 22-APR-11 20:45:00 to 23-APR-11 00:30:00 (CST-6)
Location: MASCOUTAH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Up to three inches of rain fell in a short amount of time causing flash flooding.  Several roads had water over them including Illinois Route 4 south of Mascoutah and up to 10 inches deep on the northside of Freeburg on Deerfield Court.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 22-APR-11 20:15:00 to 22-APR-11 20:20:00 (CST-6)
Location: FAYETTEVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm winds caused considerable tree damage along Drum Hill Road north of Fayetteville.  A large pine tree was snapped at the base and fell onto an unoccupied car destroying it.  Several other trees were blown over.  Also, a farm house had several windows blown out and the door to the sunroom torn off.

Tornado in MADISON, ILLINOIS
From 22-APR-11 19:55:00 to 22-APR-11 20:10:00 (CST-6)
Location: ST MORGAN
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado first touched down 3 miles southwest of Highland in Madison County, just to the east of Bluemound Road around 855 pm. It quickly moved east snapping and uprooting trees. Just before reaching Illinois Route 160, it destroyed a large metal farm building and carried the metal panels about a mile downwind.  On Old Trenton Road, it snapped three wooden power poles and snapped trees and caused minor damage to a barn roof on a farmstead.  As it continued to move east it widened to 700 yards as it passed south of Highland. It caused significant damage to trees, power poles and farm outbuildings in addition to minor roof damage. Near the intersection of St. Rose Road and Iberg Road, extensive tree damage occurred with one tree falling on a home and a second falling on a prefabricated carport. The tornado continued to move east causing varying degrees of damage to five homes in a subdivision just north of St. Rose Road. The tornado then moved across Waage Road blowing out multiple windows of a farm house and destroying a large metal shed. The tornado then crossed Baumann Road into Clinton County.  The maximum intensity for this segment was rated EF2 and was on the ground for 6.5 miles before crossing into Clinton County.  The maximum width of damage was 700 yards. As for the entire tornado, it was rated EF2, with maximum wind speeds of 130 mph.  The maximum width of the tornado was 700 yards and the total length of the tornado was 18.2 miles.