An extended period of significant tornado activity affected the

Midwest The Midwestern United States (also referred to as the Midwest, the Heartland or the American Midwest) is one of the four census regions defined by the United States Census Bureau. It occupies the northern central part of the United States. It ...

and

Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, Dixieland, or simply the South) is List of regions of the United States, census regions defined by the United States Cens ...

from April 19 to April 24, 2011, with 134 tornadoes being spawned across six days. The outbreak sequence produced an EF4 tornado that tore through the St. Louis metropolitan area on April 22, while other tornadoes caused damage in

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

, and other parts of

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

during the period. No fatalities were reported in this outbreak sequence. This event was directly followed by the largest tornado outbreak in the history of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Meteorological synopsis

April 19–20

A severe weather event developed across the Midwest and southern Great Plains on April 19 as a dynamic low pressure system tracked across the area. Thunderstorms began in the late afternoon and early evening with large

hail Hail is a form of solid Precipitation (meteorology), precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailsto ...

and several tornadoes. Significant damage was reported near Bowling Green, Missouri and Girard, Illinois as a result of an EF3 tornado. The individual storm cells later merged into a very large

squall line A squall line, or quasi-linear convective system (QLCS), is a line of thunderstorms, often forming along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front (which often are accompanied by abrupt a ...

. Overnight, the squall line tracked eastward with widespread wind damage and many embedded tornadoes across several states. A few tornadoes were as strong as EF2, but most were brief and weak.

April 22

Severe weather once again developed across parts of the Midwest on April 22. The St. Louis metropolitan area was hit hardest by the storm system. An EF4 tornado tracked across the region. Severe effects occurred in several communities, including houses and other buildings destroyed in Bridgeton, Ferguson, Florissant, Hazelwood, Maryland Heights, New Melle, and other communities. The tornado caused extensive damage to numerous facilities at

Lambert–St. Louis International Airport St. Louis Lambert International Airport is the primary international airport serving Greater St. Louis, metropolitan St. Louis, Missouri, United States. Commonly referred to as Lambert Field or simply Lambert, it is the largest and List of t ...

, with injuries reported; airplanes were damaged from the high winds and terminal windows blew out. American Airlines claimed four of their jets were damaged, two significantly. The airport was closed for days after the tornado. The EF4 tornado rating was based on finding of leveled houses in Bridgeton. Following assessments by the local National Weather Service, it was determined that a single tornado tracked for through parts of Missouri and Illinois. It reached a maximum width of . Elsewhere, there were several reported tornadoes, including an EF2 which tracked through Henderson, Webster, and Union counties.

April 23–24

Scattered tornadoes were reported across the United States, but most were weak or remained over open country. However, one EF2 tornado struck the town of Bardwell, Kentucky. Another EF2 tornado destroyed airplane hangars near

Cairo, Illinois Cairo ( , sometimes ) is the southernmost city in the U.S. state of Illinois and the county seat of Alexander County, Illinois, Alexander County. A river city, Cairo has the lowest elevation of any location in Illinois and is the only Illinoi ...

. Tornadoes were not part of the same weather system as the earlier tornadoes; they were part of a weather system that led to the

2011 Super Outbreak The 2011 Super Outbreak was the largest, costliest, and one of the deadliest tornado outbreaks ever recorded, taking place in the Southern, Midwestern, and Northeastern United States from April 25 to 28, 2011, leaving catastrophic destruc ...

Confirmed tornadoes

April 19 event

April 20 event

April 21 event

April 22 event

April 23 event

April 24 event

St. Louis, Missouri/Madison County, Illinois

This powerful tornado began near Creve Coeur Lake at 7:59 p.m. CDT (00:59 UTC) and moved into Maryland Heights, producing EF3 damage. The tornado continued eastward and reached EF4 intensity in Bridgeton, where a number of houses were completely destroyed. Afterwards the tornado traveled parallel to

Interstate 70 Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from Interstate 15, I-15 near Cove Fort, Utah, to Interstate 695 (Maryland), I-695 and Maryland Route 570 (MD 570) in Woodlawn, Baltimo ...

and struck

at EF2 intensity about 8:10 p.m. CDT (01:10 UTC). It blew out numerous windows and peeled away a large section of roof. The tornado then moved into the Berkeley neighborhood where it continued to produce EF2 damage, tearing the roofs from several homes. The tornado continued on through several more neighborhoods, causing roof damage to a church and two businesses in Ferguson, one of which completely experienced total roof loss. The storm also produced extensive tree damage and some roof damage to homes as well as partially removing the roof of an elementary school. Damage along this entire section of the storm's path was rated EF1 to low-end EF2. The tornado continued toward the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

resulting in mostly EF1 damage to trees, however EF2 damage occurred in Dellwood where extensive tree and utility pole damage occurred, and three homes lost their roofs. EF2 damage continued as the tornado crossed the

into

Madison County, Illinois Madison County is a county in the U.S. state of Illinois. It is a part of the Metro East in southern Illinois. According to the 2020 United States census, 2020 census, it had a population of 264,776, making it the eighth-most populous county in ...

, where about a hundred homes were damaged, three of which completely lost their roofs, and numerous trees were uprooted and snapped. The tornado dissipated at 8:31 p.m. CDT (01:31 UTC) in the northeastern part of

Granite City, Illinois Granite City is a city in Madison County, Illinois, United States, within the Greater St. Louis metropolitan area. The population was 27,549 at the 2020 United States census, 2020 census, making it the third-largest city in the Metro East and S ...

. It traveled and had a peak width of .

Notes

References

External links

For the latest severe weather information:
National Weather ServiceStorm Prediction Center
{{DEFAULTSORT:2011-04-19 Tornado Outbreak Sequence Tornado,2011-04-19 F4, EF4 and IF4 tornadoes Tornadoes in Alabama Tornadoes in Arkansas Tornadoes in Illinois Tornadoes in Indiana Tornadoes in Kentucky Tornadoes in Mississippi Tornadoes in Missouri Tornadoes in Ohio Tornadoes in Oklahoma Tornadoes in Texas 04-19 Tornado outbreak sequence