Tornado outbreak sequence
Encyclopedia
A tornado outbreak sequence (or extended tornado outbreak) is a period of continuous or nearly continuous high tornado
activity consisting of a series of tornado outbreak
s over multiple days with no or very few days lacking tornado outbreaks.
Major tornado outbreak sequences occurred in the United States
in May 1917, 1930, 1949, 2003
, and April 2011. Another exceptional outbreak sequence apparently occurred during mid to late May 1896
. Tornado outbreak sequences tend to dominate the tornado statistics for a year and often cause a spike in tornado numbers for the entire year. Not all periods of active tornado activity are outbreak sequences, there must be no break in the activity to satisfy the definition.
Tornado
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 or, in rare cases, the base of a cumulus cloud. They are often referred to as a twister or a cyclone, although the word cyclone is used in meteorology in a wider...
activity consisting of a series of tornado outbreak
Tornado outbreak
While there is no single agreed upon definition, generally at least 6-10 tornadoes produced by the same synoptic scale weather system is considered a tornado outbreak. The tornadoes usually occur within the same day, or continue into the early morning hours of the succeeding day, and within the...
s over multiple days with no or very few days lacking tornado outbreaks.
Major tornado outbreak sequences occurred in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in May 1917, 1930, 1949, 2003
May 2003 tornado outbreak sequence
The May 2003 tornado outbreak sequence in the United States was a series of tornado outbreaks that occurred from May 3 to May 11, 2003. Tornadoes began occurring over the affected area on April 30, but the most prolific continuous period was the seven day period of May 4–10...
, and April 2011. Another exceptional outbreak sequence apparently occurred during mid to late May 1896
May 1896 tornado outbreak sequence
The May 1896 tornado outbreak sequence was a series of violent and deadly tornado outbreaks that struck much of the Central and Southern United States from May 15 to May 27, 1896. It is considered one of the worst tornado outbreak sequences on record. There were four particularly notable tornado...
. Tornado outbreak sequences tend to dominate the tornado statistics for a year and often cause a spike in tornado numbers for the entire year. Not all periods of active tornado activity are outbreak sequences, there must be no break in the activity to satisfy the definition.