Tornado Facts

One of the first tornado facts must necessarily deal with where the world ‘tornado’ came from. ‘Tornado’ has its genesis in the Spanish language, the root being the word tronada (‘thunderstorm’). ‘Tronada’ stems from the Latin word ‘tonare (‘to thunder’). However, language specialists opine that the present form of the word derives from a combination of the Spanish ‘tronada’ and ‘tornar’, which means ‘to turn’.

A tornado is a rapidly rotating air column that connects with both a cloud base and the surface of the earth. These violent natural manifestations appear in many sizes. However, their most typical form is that of a visible condensation funnel in which the narrow end touching the earth. Invariably, a cloud of debris picked up with the tornado’s incredible suction power encircles the lower portion of the funnel.

Tornadoes can have incredible wind speeds associated with them. The garden-variety tornado can be as high as 110 mph, or 175 km/h and measure up to 250 feet (or 75 meters) across. On the other hand, some of the more destructive tornadoes feature wind speeds as high as 300 mph (or480 km/h) and above. They can measure more than a mile across and prevail on the ground for 12 miles or more. Tornadoes do not typically travel for more than a few miles before losing steam and dissipating

Tornadoes occur on every continent of the globe, with the exception of Antarctica. America has the highest incidence of tornadoes, but they are also common occurrences in New Zealand, western and southeastern Australia, south-central Canada, northwestern and central Europe, Italy, south central and eastern Asia, east-central South America, and Southern Africa.

It is a myth that all tornadoes are visible to observers. Many times, they travel along the surface of the earth without any physical manifestation and their existence is only evident by the destruction they leave in their path. It is however true that most tornadoes are visible, because the very low pressure brought about by the fast wind speeds and rapid rotation invariably causes water vapor in the air to condense into a condensation funnel that is observable seen by the naked eye.

Technically, a tornado consists of the vortex of wind, while the condensation cloud is just a visible manifestation. The visible funnel cloud does not feature any strong winds at the surface and funnel clouds do not necessarily turn into tornadoes. However, it is a fact that a funnel cloud usually precedes a tornado as a force known as mesocyclonic rotation descends toward the ground.

A mesocyclone is a cyclonic vortex of air that appears in updrafts, sometimes resulting in tornadoes. They measure from 2-10 km diameter. It is not always possible to differentiate a funnel cloud from a tornado, because tornadoes invariably cause strong winds at the surface while the visible funnel is still above the ground.

In some cases, a single storm can cause the manifestation of many tornadoes and mesocyclones. Experts refer to this phenomenon as cyclic tornadogenesis, and to tornadoes that result from the same storm as tornado families. Multiple tornadoes can also result from the same large-scale storm system. A tornado outbreak results when this happens without a break in activity involved. A tornado outbreak sequence occurs when tornado outbreaks lasts for several successive days with in the same general area.