A tornado family is a series of

tornado A tornado is a violently 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. It is often referred to as a twister, whirlwind or cyclone, altho ...

es spawned by the same

supercell A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms (s ...

thunderstorm. These families form a line of successive or parallel tornado paths and can cover a short span or a vast distance. Tornado families are sometimes mistaken as a single continuous tornado, especially prior to the 1970s. Sometimes the tornado tracks can overlap and expert analysis is necessary to determine whether or not damage was created by a family or a single tornado. In some cases, such as the Hesston-Goessel, Kansas tornadoes of March 1990, different tornadoes of a tornado family merge, making discerning whether an event was continuous or not more difficult. Some tornado damage remains a mystery even today due to a lack of evidence. The

Tri-State Tornado On March 18, 1925, one of the deadliest tornado outbreaks in recorded history generated at least twelve significant tornadoes and spanned a large portion of the midwestern and southern United States. In all, at least 751 people were ki ...

of March 1925 was one such event. It could either have been the longest single tornado recorded or a family of tornadoes. A thorough re-analyses project found that it was probably one continuous tornado for most of its path, likely bounded by separate tornadoes at the beginning and end of the very long track (VLT) tornado, and likely another significant tornado spawned many miles later. However, many other exceptional VLT events were later found to be tornado families with much shorter tornado path segments than originally thought, notably the Woodward, Oklahoma tornado family of April 1947 and the Charleston-Mattoon, Illinois tornado family of May 1917. Tornado families can be a result of

satellite tornado A satellite tornado is a tornado that revolves around a larger, primary tornado and interacts with the same mesocyclone. Satellite tornadoes occur apart from the primary tornado and are not considered subvortices; the primary tornado and satellit ...

es, cyclic tornadogenesis, or some combination thereof. Intense

downburst In meteorology, a downburst is a strong downward and outward gushing wind system that emanates from a point source above and blows radially, that is, in straight lines in all directions from the area of impact at surface level. Capable of pro ...

s may also cause damage paths to appear continuous, although this was more an issue for historic tornadoes as such damage usually is now distinguishable as caused by

straight-line wind In meteorology, a downburst is a strong downward and outward gushing wind system that emanates from a point source above and blows radially, that is, in straight lines in all directions from the area of impact at surface level. Capable of pro ...

s. Especially when newly forming, tornadoes may sometimes exhibit brief breaks in the damage path even as the parent circulation is continuous. Such events may be considered as " skipping", a term that originally referred to what now is typically a tornado family. Successive tornadoes may be considered by some as separate tornadoes (and thus constituting a tornado family) only when spawned by a new tornadocyclone or low-level

mesocyclone A mesocyclone is a meso-gamma mesoscale (or storm scale) region of rotation (vortex), typically around in diameter, most often noticed on radar within thunderstorms. In the northern hemisphere it is usually located in the right rear flank (back ...

(and from within a new

wall cloud A wall cloud (murus or pedestal cloud) is a large, localized, persistent, and often abrupt lowering of cloud that develops beneath the surrounding base of a cumulonimbus cloud and from which tornadoes sometimes form. It is typically beneath the r ...

References

{{DEFAULTSORT:Tornado Family Tornado Tornadogenesis

See also

References