Tornadoes are the fastest most violent winds on earth. A whirlwind with murderous force, bringing destruction with devastating power to our planet. They are the constant reminders that we may be able to predict natures behaviour, but not able to control the nature. But we can try to understand how they work, how they originate and how they behave.

Circumstances
Tornadoes require unique circumstances. There must be warm moist air in the lower atmosphere, much colder and drier air aloft, there must be land and there must be something to give the air near the ground an upward shove. Often this is heated air that wants to rise, because it's lighter that the surrounding air. When the warm air collides with the coller air, the warm moist air will be driven upwards, this is also known as an updraft. On top of the column of rising air is a dome. this is also called an overshooting top. In weaker storms these domes come and go, but when the dome lasts for at least 20 minutes you're almost for certain looking at a spuer cell. On the highest top the warm air will cool and condense, forming clouds. The cool air goes down (this is known as downdraft) where it is getting warm again. So in fact it is a circular course of warm moist air and cooler, drier air. These warm and colt air drafts collide and twist around each other, making the cloud become a titanic mass of turbulent air or super cell. These giant clouds can be 20 kilometres high and as much as 32 kilometres width.

Super cells
A super cell is in fact a very strange appearance. While most storms have several updrafts and downdrafts which interfere with each other, a super cell has only one updraft and only one downdraft. This way the super cell allows itself to feed off itself, giving it a long and intense life. also see sub-division super cells. Because the super cell "lives" so long, it can create massive hailstones. Also see sub-division hailstones.

Mesocyclone
Back to the development of a tornado. When the combination of wind speeds and changing directions in a super cell is right the air will rotate, causing a mesocyclone to form. So the air near a mesocyclone is rotating and rising. Where air rises there aren't water droplets, so there won't fall any rain in that area. Since tornadoes are made of rising air, they never form in the neighbourhood of any rain. When the mesocyclone is powerful enough the actual tornado will form. Often, a tornado is located on the edge of the updraft, next to air that's coming down from the thunderstorm with falling rain or hail. This is why a burst of heavy rain or hail sometimes announces a tornado's arrival. Although the air is rising in a tornado, the funnel itself grows from the cloud toward the ground as the tornado is forming. The term "funnel cloud'' refers to a tornado-like vortex that doesn't reach the ground. When a funnel cloud touches the ground, it becomes a tornado. Often, however, apparent funnel clouds are already tornadoes. But the part nearest the ground is still invisible because cloud hasn't formed there and little dirt is being picked up. Don't think you're safe near or under a funnel cloud.

More funnels
Often there are more funnels which rotate around the main funnel, but they often remain invisible because of the debris, dust and the clouds. These suction vortixes are most common in F4 or F5 tornadoes using the Fujita scale.

Why do they have different colours?
When the funnel is on the ground it often has a brown colour from the dust and debris. As the swirling winds pick up dust, dirt, and debris from the ground, the funnel turns even darker. Twisters that pick up little dirt can retain their white, cloud coloration. Some tornadoes have taken on a red hue by picking up red dirt.

How fast do they travel and how long do they stay?
As the parent thunderstorm travels along, tornadoes can come down from the cloud, run along the ground and lift back up to be followed by other tornadoes. Tornadoes that are on the ground move with a top speed of 110 kilometres per hour. They meanly stay about 10 minutes on the ground, but a few monster tornadoes from a mile or more wide and can last for an hour or more.