A mile-wide tornado at Binger, Oklahoma (1981) Public Domain image.

A tornado is born from a powerful storm called a supercell. Tornadoes have been reported in all states, but most tornadoes happen in the central parts of America called “Tornado Alley.” In some supercells, warm, moist air rises quickly into the atmosphere. Winds blowing at different speeds at different parts of the supercell produce wind shear and cause a horizontal, rotating column of air. A funnel cloud will form as the air column rotates faster and more tightly within the supercell. The rain and hail within the storm cause the funnel cloud to touch the ground resulting in a tornado. The strength of a tornado is measured by what’s called the Fujita scale. The weakest tornadoes (F0) feature winds of 40-78 miles per hour, while the strongest tornadoes (F5) have winds of up to 318 miles per hour. All tornadoes can be devastating, especially if they touch down in areas with lots of people.

Tornado Outbreak

A tornado outbreak occurs when one storm system produces multiple tornadoes. Some tornado outbreaks can result in the formation of dozens of tornadoes over several states. One particularly powerful tornado outbreak occurred between April 25 and April 28 of 2011, where a record 355 tornadoes in 21 states and Canada were recorded, including an F5 tornado that completely destroyed parts of Tuscaloosa, Alabama. Much of the destruction was caught on camera and broadcast across the country and internet. The same weather system produced hailstones that measured 4.5 inches across in southern Virginia. 328 people were killed as a result of the outbreak, which totaled over $11 billion in damages.

Devastating Tornadoes Interactive Map

Tri-State Tornado 1925 Natchez Tornado

1.) Tri-state Tornado

The F5 Great Tri-state Tornado occurred on March 18, 1925 in southeastern Missouri, Southern Illinois, and southwestern Indiana, killing a record 695 people. Its 150-235 mile track is the longest in recorded history for a tornado. It was part of a larger tornado outbreak that spawned at least eleven other major tornadoes in Kansas, Tennessee, Alabama, and Kentucky, five of which were F3 in intensity or larger.

2.) Natchez Tornado

The second deadliest tornado in American history hit the Mississippi River port town on May 7, 1840. It killed 317 people and because there was not Fujita Scale at the time, the tornado was not categorized. As the tornado raged directly on the shores of the Mississippi River, most of the victims of the tornado died when their flatboats were sunk or destroyed. The death toll may have been much higher and many slaves were said to have been killed and likely not counted.

3.) St. Louis Tornado

The St. Louis-East St. Louis tornado struck the Mississippi River port cities on May 27, 1896. Part of a larger outbreak that pummeled parts of the Midwest and east, the third deadliest tornado in American history killed 255 people, 137 of which were killed when the tornado traveled through downtown St. Louis. The massive tornado then crossed the Mississippi River, where it picked up intensity and devastated East St. Louis, Illinois, killing another 117 people.

4-5) Tupelo/Gainesville Tornado

The Tupelo-Gainesville tornadoes were two of twelve tornadoes in an outbreak that devastated the Deep South between April 5-6 1936. Together the two tornadoes killed 419 people and the outbreak resulted in the deaths of 454. The first tornado on April 5th, in Tupelo, Mississippi, completely leveled 48 city blocks and as many as 900 homes. Interestingly, one of the survivors of the storm was a one year-old Elvis Presley. The next morning, two tornadoes converged and merged in downtown Gainesville, Georgia. The total devastation included the collapse and subsequent fire at the Cooper Pants Factory which killed 70 workers. A nearby Newman's Department store also collapsed amidst the powerful winds, killing 20. Letters from the mangled mailboxes of the small town were found 70 miles to the east in Anderson, South Carolina.

6.) Woodward Tornadoes

The Woodward Tornadoes, officially called the Glazier-Higgins-Woodward Tornado, were spawned from a single supercell on April 9, 1947. One of the tornadoes, thought to be an F5, carved a 125-mile path from Texas to Oklahoma. It was this tornado that completely destroyed tiny Glazier, Texas, where it killed 17 people, before slamming into Higgins, Texas, where it killed 51. At points along its path, its vortex was thought to be at least two miles wide! The tornado, next crossed into Woodward, Oklahoma where it would become the deadliest tornado in state history, killing 107 and destroying Woodward.

7.) Joplin Tornado


"2011 Joplin, Missouri tornado damage" by KOMUnews -

http://www.flickr.com/photos/komunews/5756447784/. Licensed under CC BY 2.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:2011_Joplin,_Missouri_tornado_damage.jpg

On May 22, 2011, a multi-vortex F5 tornado slammed into Joplin in southwest Missouri, killing 158 and causing nearly three billion dollars in damage. It was the costliest tornado in American history. Unlike most of the previous tornadoes, the Joplin tornado and its aftermath were broadcast on television and the internet where scenes of utter devastation were more reminiscent of a warzone than part of a city. When President Barack Obama toured he called the devastation the worst he had ever seen.

8.) Amite/Pine/Purvis Tornado

The Amite/Pine/Purvis Tornadoes were part of what is called the 1908 Dixie Tornadoes, which caused at least 29 tornadoes in 13 states. The F4 tornado that hit Purvis, Mississippi was so powerful that it left only seven buildings standing in the entire town. 55 people were killed in Purvis and 143 total as a result of the tornado.

9.) New Richmond Tornado

The New Richmond tornado was an estimated F5 tornado that occurred on June 12, 1899. It practically destroyed New Richmond, leveling 500 buildings. To make matters worse, the tornado occurred as people were walking home from the Gollmar Brothers Circus. Most had little if any time to hide or escape. In all, the tornado killed 117 people and injured 125 more.

10.) Flint Tornado

The Flint Tornado was part of a devastating and rare tornado outbreak in early June of 1953 that affected the upper Midwest and northeast. It featured several strong tornadoes - a suspected F5 that hit Flint Michigan, and a suspected F4 that hit over 500 miles away in Worcester, Massachusetts. The Flint tornado resulted in the deaths of 116 people and the Worcester tornado killed 90. Strong tornadoes also hit Ohio and New Hampshire. This tornado outbreak is thought to have produced at least 22 tornadoes with intensities of F2 or greater. The location of the outbreak was so unusual that some in the U.S. Government thought it might have been the result of nuclear testing.