Did You Know?
Owing to the vast presence of flat and low-lying topography, the United States has more occurrences of tornado than any other country in the world.
Formation of a Tornado
A mesocyclone is a presence or formation of spinning air within a convective storm. This region of spinning motion (usually within a fluid) is called a vortex. Here, the cyclonic air travels and rotates in a vertical axis.
It forms when the speed of wind -- depending on the height, sets the air spinning in a horizontal manner, called crosswise spin. The updraft (vertical air movement) of the thunderstorm then subjects the air to travel in a vertical mode.
Now, the entire column of the spinning air rotates as a column perpendicular to the surface of the ground, known as streamwise spin. It eventually results into a whirling air column having a weak rotation known as a mesocyclone.
Here, the force that sets the inward movement of the air in the rotating column is balanced and matched by the centrifugal force taking place in the outward direction.
The air that travels around the mesocyclone axis is taken via the bottom portion of this dynamic pipe. This results in an agitated rotation at the pipe's bottom and pushing upward of the inflow air entering the pipe. The mesocyclone thus increases in height, further intensifying its rotating speed.
A tornado can either be a supercell or a non-supercell. In a non-supercell tornado, the foremost condition for its formation is that the crosswise spin has to be formed as the first stage. The other essential factor is the presence of a thundercloud. In case of a supercell tornado, the tornado develops from the mesocyclone of a supercell thunderstorm.
Researching and understanding the science behind formation of a tornado is not yet fully developed. Since a tornado does not always travel close to the meteorological instruments, its intensity is often gauged by analyzing the destruction and damage it causes.