An extended period of significant tornado activity affected the

Midwest The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four Census Bureau Region, census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of ...

and

Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...

from April 19 to April 24, 2011, with 134 tornadoes being spawned across six days. The outbreak 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. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

Oklahoma Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...

, and other parts of

Missouri Missouri 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 is bordered by eight states (tied for the most with Tennessee ...

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

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

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 In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

tracked across the area. Thunderstorms began in the late afternoon and early evening with large

hail Hail is a form of solid 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 hailstone. Ice pellets generally fal ...

and several tornadoes. Significant damage was reported near

Bowling Green, Missouri Bowling Green is a city in Pike County, Missouri, United States. The population was 5,334 at the 2010 census. It is the county seat of Pike County. History Bowling Green was settled in 1819, and designated county seat in 1824. Settled chiefly b ...

and

Girard, Illinois Girard is a city in Macoupin County, Illinois, Macoupin County, Illinois, United States. The population was 2,103 at the 2010 census, and 2,010 at a 2018 estimate. History Girard is named after Stephen Girard Geography Girard is located at (39.4 ...

as a result of an EF3 tornado. The individual storm cells later merged into a very large

squall line A squall line, or more accurately a 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 accompa ...

. 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 The Enhanced Fujita scale (abbreviated as EF-Scale) rates tornado intensity based on the severity of the damage they cause. It is used in some countries, including the United States, Canada, China, and Mongolia. The Enhanced Fujita scale repla ...

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 commercial airport serving metropolitan St. Louis, Missouri, United States. Commonly referred to as Lambert Field or simply Lambert, it is the largest and busiest airport in the state o ...

, 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 Bardwell is a home rule-class city in and the county seat of Carlisle County, Kentucky, United States. The city was formally incorporated by the state assembly in 1878. The population was 714 at the 2020 census, down from 723 in 2010. History ...

. Another EF2 tornado destroyed airplane hangars near

Cairo, Illinois Cairo ( ) is the southernmost city in Illinois and the county seat of Alexander County. The city is located at the confluence of the Ohio and Mississippi rivers. Fort Defiance, a Civil War camp, was built here in 1862 by Union General Ulysses ...

. 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 25–28, 2011, leaving catastrophic destruction ...

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 Maryland Heights is a second-ring north suburb of St. Louis, located in St. Louis County, Missouri, United States. The population was 27,472 at the 2010 census. The city was incorporated in 1985. Edwin L. Dirck was appointed the city's first may ...

, 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 System, Interstate Highway in the United States that runs from Interstate 15, I-15 near Cove Fort, Utah, to a park and ride lot just east of Interstate 695 (Maryland), I-695 in ...

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 Berkeley most often refers to: *Berkeley, California, a city in the United States **University of California, Berkeley, a public university in Berkeley, California * George Berkeley (1685–1753), Anglo-Irish philosopher Berkeley may also refer ...

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 second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...

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 census, it had a population of 264,776, making it the eighth-most populous county in Illinois and the most popu ...

, 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 census, making it the third-largest city in the Metro East and Southern Illinois regions, ...

. 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 tornadoes by date 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 A tornado outbreak sequence, or tornado outbreak day sequence, sometimes referred to as an extended tornado outbreak, is a period of continuous or nearly continuous high tornado activity consisting of a series of tornado outbreaks over multiple days ...