A tornado is a violent and dangerous column of air that is in contact with both the surface of the earth as well as a cumulonimbus cloud. Resembling a condensation funnel, with the narrow part touching the surface of the earth, a tornado is encircled by a cloud of debris and dust. There are different types of tornadoes in the world, including landspout, multiple vortex tornado, and waterspout. Tornado prone regions of the world are the United States, parts of Europe and South America, Southern Africa, Australasia and far eastern Asia. The only continent that has not experienced a tornado till date is Antarctica.
The wind speed in a tornado can range from 40 mph to 110 mph, but there have been records of the wind speeds reaching 318 mph also. A tornado is formed when a thunderstorm occurs. The most common type of thunderstorm for forming a tornado is the supercell. When both high pressure and low pressure air interact with each other, the low pressure draws in high pressure air to form the vortex and eventually results in a tornado. Tornadoes can also accompany hurricanes and tropical storms that move over the land. Read through the following lines to know what causes tornadoes.
How Is A Tornado Created
In spring and summer, the ground gets warmer and the air aloft gets cold. The warm air near the surface of the earth rises in the air. The rising air cools and the water vapors being carried by it condense to form clouds and thunderstorms. The winds near the surface of the ground begin blowing in one direction, while the winds aloft blow in the opposite direction. The difference between the two winds creates a horizontally rotating mass of air. The warm, rising air creates an updraft that pulls the rotating air along with it upwards. The thunderstorm thus created forms a rotating vortex or mesocyclone.
The vortex begins to draw the clouds to the ground, forming a funnel. The high pressure air being sucked into the tornado creates winds that cause destruction on a massive scale. Gradually, the tornado matures and strengthens by drawing in more moist warm air towards it. This stage is the most dangerous, as it increases in intensity and lasts for a longer period of time. When the down draft of air cool down, the funnel begins to shut down, as the supple of warm air reduces. This marks the end of a tornado. Gradually, the tornado begins to thin and gets less developed. It loses energy and the funnel completely disperses.
Tornadoes always form in groups called families or outbreaks. The intense rotation of strong and larger tornadoes creates the weaker tornadoes.