Thunderstorms are quite common in nature and one of the types that is most destructive, is the one that produces a tornado. In this article you will learn a bit about the way these tornadoes appear and what causes their appearance. For the most part, the collision between huge air volumes is to blame when it comes to tornadoes. Whenever a massive quantity of cold and warm air comes in contact, the result can be a tornado. Since the warmer air stays below while the cold one stays above, an area of low pressure forms when the warmer air tries to go up, which can mean a vorticy forms a may produce a funnel cloud or an actual tornado. A tornado usually occurs only in certain areas and only when the needed climatic conditions appear.

Observations mention that in many cases, before a tornado is formed, the wind is known to have changed direction. As the wind speed increases, the wind starts going up, which can have as a result an effect of horizontal spinning which takes place in the area of the lower atmosphere. Later, the change takes place in the vertical as well. The thunderstorm starts to grow at this point and it can have a circumference between 2 and 6 miles.

Eventually, the thunderstorm evolves a wall cloud and may become a tornado. The tornado can be accompanied by a number of other phenomena, including hailstorms.

There are three main categories that tornadoes are classified in, which are based on tornado formation factors. They can be violent, strong or weak tornadoes and a number of factors will influence the category in which the tornado is classified. The amount of damage done by a tornado and the number of people that died can be factors which influence the category. The majority of the tornadoes are considered weak. There are many strong as well, but the ones considered violent are few.