When most people here the words "tornado" or "cyclone" you can be positive that one thing would come to their mind: 'The Wizard Of Oz.'  I know that's what I think of.  Like in 'The Wizard Of Oz' tornados do have devistating power. You would remember how Dorothy's whole house got taken from Kansas to the Land Of Oz, and, how as she was going there through the tornado she saw many things like cows and people.  When a tornado hits, it takes everything in it's path, including houses, cars, animals, people and even train tracks.  They might come down again later far from where they were standing when the tornado first got them.

What Is A Tornado?

A tornado is defined as a violently rotating column of air in contact with the ground and pendent from a cumulonimbus cloud or thunder storm. Tornados can be placed in different classes such as weak, strong or violent. About 7 in 10 tornadoes are weak, with rotating wind speeds no greater than about 110 MPH.  The average strong tornado is most often seen in a funnel shape and has winds that vary from 110 to 200 MPH. 3 in 10 tornados are strong. Only violent tornadoes are capable of leveling a well-anchored, solidly constructed home. Fortunately, less than 2 percent of all tornadoes reach the 200+ MPH violent category. Also, most violent tornadoes only produce home-leveling damage within a very small portion of their overall damage.

What Causes Tornados?

Tornados are started in thunderstorms, and if the right conditions occur one or more tornados can spin out from one thunderstorm. There is 3 conditions that are required for a thunderstorm to start or occur. These conditions are:
1) Moisture in the lower to mid levels of the atmosphere.
2) Unstable air, meaning the air will continue rising once it starts rising from the ground.
3) A force that will cause the air to begin rising, or a 'rising force'.  The most common force is heated air near the ground.  That air will rise as it gets warmer.

When those conditions are present humind air rises high into the sky, also known as an updraft.  As this hot, humid air rises, it gets cooled and condensed into cloud form.  Clouds like this can tower more than 50,000 feet into the air.  The updraft can have winds upwards at more than 100 MPH. Hail and rain is formed in thunderstorms . Positive and negitive charges become separeted,  creating the areas of different charges that lead to lightning and thunder.

Tornados form in the air rising to the thunderstorm, in the updraft.  Stronger tornados are located near the edge of the updraft, close to where the air is descending.  Rain and hail pull air down to cause downdrafts which is why, right before a tornado, a burst of rain or hail will hit. Since the tornado is in rising air, wind is flowing in from air around into the tornado. This means that damaging winds can hit hundreds of yards from the actual tornado vortex.