Tornado
Overview
 
A tornado is a violent, dangerous, rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud
Cumulonimbus cloud
Cumulonimbus is a towering vertical cloud that is very tall, dense, and involved in thunderstorms and other inclement weather. Cumulonimbus originates from Latin: Cumulus "Heap" and nimbus "rain". It is a result of atmospheric instability. These clouds can form alone, in clusters, or along a cold...

 or, in rare cases, the base of a cumulus cloud
Cumulus cloud
Cumulus clouds are a type of cloud with noticeable vertical development and clearly defined edges. Cumulus means "heap" or "pile" in Latin. They are often described as "puffy" or "cotton-like" in appearance. Cumulus clouds may appear alone, in lines, or in clusters...

. They are often referred to as a twister or a cyclone, although the word cyclone
Cyclone
In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...

 is used in meteorology in a wider sense, to name any closed low pressure
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...

 circulation. Tornadoes come in many shapes and sizes, but are typically in the form of a visible condensation funnel
Funnel cloud
A funnel cloud is a funnel-shaped cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud but not reaching the ground or a water surface. A funnel cloud is usually visible as a cone-shaped or needle like protuberance from the main cloud...

, whose narrow end touches the earth and is often encircled by a cloud of debris
Debris
Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...

 and dust
Dust
Dust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...

.
Timeline

1680    The first confirmed tornado in America kills a servant at Cambridge, Massachusetts.

1840    The Great Natchez Tornado strikes Natchez, Mississippi killing 317 people. It is the second deadliest tornado in United States history.

1880    An F4 tornado strikes Marshfield, Missouri, killing 99 people and injuring 100.

1893    The small town of Pomeroy, Iowa, is nearly destroyed by a tornado that kills 71 people and injures 200.

1899    New Richmond Tornado: the eighth deadliest tornado in U.S. history kills 117 people and injures around 200.

1926    The deadliest November tornado outbreak in U.S. history strikes on Thanksgiving day. 27 twisters of great strength are reported in the Midwest, including the strongest November tornado, an estimated F4, that devastates Heber Springs, Arkansas. There are 51 deaths in Arkansas alone, 76 deaths and over 400 injuries in all.

1948    The first successful tornado forecast predicts that a tornado will strike Tinker Air Force Base, Oklahoma.

1953    In Warner Robins, Georgia, an F4 tornado kills 18 people.

1953    Flint-Worcester tornado outbreak sequence: A tornado hits Flint, Michigan, and kills 115. This is the last tornado to claim more than 100 lives.

1955    In the United States, a night time F5 tornado strikes the small city of Udall, Kansas, killing 80 and injuring 273. It is the deadliest tornado to ever occur in the state and the 23rd deadliest in the U.S.

Quotations

Scenes of suffering and horror marked the storm and fire. Throughout the night relief workers and ambulances endeavored to make their way through the streets strewn with wreckage, fallen telegraph poles and wires and burning embers. The only light afforded was that of the burning area…

St. Louis Post-Dispatch, March 20, 1925

 
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