In general terms, most scientists do not know the exact, or approximate cause for the formation of storms. Although this is generally the accepted case, they do have a general idea as to how storms like tornados form. Basically, all tornados start the same way. They all begin with a single thunderstorm cloud that contains a vast amount of unstable energy. Depending on the amount of energy within the thunderstorm, such storms can cause an updraft into the thunderstorm cloud. In a specific thunderstorm cloud known as a super cell, updrafts are generally incredibly strong, and can tend to cause a rotating ‘vortex’ within the cloud. The tornado actually forms below this vortex. As the vortex gets narrow, it begins rotating faster and faster. Once it touches the ground this vortex is considered to be a tornado.