A tornado is a violently rotating column of air that rotates while in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud.
Earth is the third planet from the Sun, the densest planet in the Solar System, the largest of the Solar System's four terrestrial planets, and the only astronomical object known to harbor life.
In meteorology, a cloud is an aerosol comprising a visible mass of minute liquid droplets or frozen crystals, both of which are made of water or various chemicals.
Cumulonimbus, from the Latin cumulus and nimbus, is a dense, towering vertical cloud, forming from water vapor carried by powerful upward air currents.
SCARIEST TORNADO EVER !!! by Pecos Hank
They are often referred to as twisters or cyclones, although the word cyclone is used in meteorology to name any closed low pressure circulation.
Tornado Size Comparison by Reigarw Comparisons
Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust.
Debris or débris is rubble, wreckage, ruins, litter and discarded garbagetrash, scattered remains of something destroyed, discarded, or as in geology, large rock fragments left by a melting glacier etc. Depending on context, debris can refer to a number of different things.
A funnel is a pipe with a wide mouth and a narrow stem.
Most tornadoes have wind speeds less than 110 miles per hour, are about 250 feet across, and travel a few miles before dissipating.
The most extreme tornadoes can attain wind speeds of more than 300 miles per hour, are more than two miles in diameter, and stay on the ground for dozens of miles.
Various types of tornadoes include the landspout, multiple vortex tornado, and waterspout.
In fluid dynamics, a vortex is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved.
A landspout is a term coined by meteorologist Howard B. Bluestein in 1985 for a kind of tornado not associated with a mesocyclone.
A multiple-vortex tornado is a tornado that contains several vortices rotating around, inside of, and as part of the main vortex.
Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud.
They are generally classified as non-supercellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes.
A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft.
These spiraling columns of air frequently develop in tropical areas close to the equator, and are less common at high latitudes.
The Equator usually refers to an imaginary line on the Earth's surface equidistant from the North Pole and South Pole, dividing the Earth into the Northern Hemisphere and Southern Hemisphere.
The polar regions of Earth, also known as Earth's frigid zones, are the regions of Earth surrounding its geographical poles.
Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirls, and steam devil; downbursts are frequently confused with tornadoes, though their action is dissimilar.
A downburst is a strong ground-level wind system that emanates from a point source above and blows radially, that is, in a straight line in all directions, from the point of contact at ground level.
A fire whirl – also commonly known as a fire devil, or,, as a fire tornado, firenado, fire swirl,or fire twister – is a whirlwind induced by a fire and often made up of flame or ash.
A gustnado is a short-lived, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm.
Tornadoes have been observed and documented on every continent except Antarctica.
However, the vast majority of tornadoes occur in the Tornado Alley region of the United States, although they can occur nearly anywhere in North America.
Tornado Alley is a colloquial term for the area of the United States where tornadoes are most frequent.
They also occasionally occur in south-central and eastern Asia, northern and east-central South America, Southern Africa, northwestern and southeast Europe, western and southeastern Australia, and New Zealand.
Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics, and including several countries.
Tornadoes can be detected before or as they occur through the use of Pulse-Doppler radar by recognizing patterns in velocity and reflectivity data, such as hook echoes or debris balls, as well as through the efforts of storm spotters.
A pulse-Doppler radar is a radar system that determines the range to a target using pulse-timing techniques, and uses the Doppler effect of the returned signal to determine the target object's velocity.
Storm spotting is a form of weather spotting in which observers watch for the approach of severe weather, monitor its development and progression, and actively relay their findings to local authorities.
A tornadic debris signature, often colloquially referred to as a debris ball, is an area of high reflectivity on weather radar caused by debris lofting into the air, usually associated with a tornado.
There are several scales for rating the strength of tornadoes.
The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale.
The Fujita scale, or Fujita–Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation.
An F0 or EF0 tornado, the weakest category, damages trees, but not substantial structures.
An F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers.
A skyscraper is a tall, continuously habitable building of over 10 floors, mostly designed for office, commercial and residential uses.
The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes.
Doppler radar data, photogrammetry, and ground swirl patterns may also be analyzed to determine intensity and assign a rating.
Photogrammetry is the science of making measurements from photographs, especially for recovering the exact positions of surface points.