Earth’s weather can produce various kinds of windstorm which include waterspouts, dust devils and tornadoes.
Although they have the common features of a column of rotating air, they are actually formed through different processes.
Dust devils and small whirlwinds are caused by severe local heating of the earth’s surface that makes the air rise rapidly.
The interaction of air current high up, produce tornadoes and they are always accompanied by intense thunderstorms.
The US records the highest number of tornadoes. Late winter or early spring when the climate is unstable is the prime season for tornadoes.
The birth of tornadoes takes place within thunderstorms. Most of them are produced in the super-cell thunderstorms but hurricanes and squall lines can also produce tornadoes.
It is not yet known clearly about how tornadoes are actually formed. We conjecture winds from different directions results in the total thunderstorm rotating. Within it, the cold and warm air currents counteract and form an air column that spins, the mesocyclone; this at times may result in a wall cloud that is a sure sign of an upcoming tornado.
This mesocyclone spins down the updraft of the cloud thus turning it into a funnel cloud. By the time it touches the ground, it turns into a tornado. It takes up the color of whatever debris it is sucking in. Depending on the landform on which it is moving tornadoes can be either invisible or partly visible.
The tornadoes move along with the source thunderstorm. The course of destruction rages from 30 feet to over half a mile. The tornadoes can travel anywhere from some yards to hundreds of miles speeding at a rate as high as 300 miles an hour, with the updraft speed moving up to 180 miles an hour. Sometimes tornadoes last for a few seconds and sometimes for more than an hour; but on average tornadoes last for about 15 minutes.