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Tornadoes are formed by an instability in the atmosphere. When there is a strong thunderstorm, they can form when a downward flow of cold air from clouds meets a rising flow of warm air from the ground. When the conditions are just right, a tornado will start. In some parts of the world, like central areas of the United States, there are frequent tornadoes, that kill many people and do a lot of damage. Here in New Zealand we do have some tornadoes, but they are relatively rare, and not as big or powerful as the ones in America. Tornado came from the Spanish word tronada, and they are also called twisters. |
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The air inside a tornado is swirling in a tight circle at incredible speeds. These winds are so strong that they destroy everything they touch, and can lift cattle, trucks and buildings high into the air and drop them a long way away. The force of these winds is so strong that it can even drive a piece of straw into a plank of wood like a nail! In the pictures below, you can see a sequence of photos taken over eight minutes, showing a small tornado forming, touching the ground, and then dissipating. |
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