How is a tornado formed?

A tornado is one of the most frightening and destructive forces in nature: a dark, spinning funnel that can tear apart buildings and toss heavy objects through the air. Tornadoes are dramatic, fast, and powerful. Yet they do not appear out of nowhere. A tornado is born from a thunderstorm, and it takes a very specific combination of conditions for one to form.

Tornadoes come from powerful thunderstorms. The strongest tornadoes are linked to a special, intense kind of thunderstorm called a supercell. These storms begin when warm, moist air near the ground rises rapidly into cooler air above. This rising air, called an updraft, builds tall storm clouds. But a strong updraft alone is not enough to make a tornado. Something has to make the air spin.

The key extra ingredient is wind shear. Wind shear means that winds at different heights blow at different speeds and in different directions. When this happens, it can set the air rolling, creating an invisible tube of horizontally spinning air, a bit like a pencil rolling on a table. As long as this spin stays horizontal, there is no tornado. But the storm's powerful updraft can grab this rolling tube of air and tilt it upward, so that it is spinning around a vertical line instead.

Once the spinning air is upright, a large rotating section forms within the storm. As the rotation tightens and speeds up, much like a spinning skater pulling in their arms, it can form a narrow, fast-spinning column. If this violently rotating column extends all the way down and touches the ground, it officially becomes a tornado. The funnel often becomes visible as moisture condenses inside it and as it picks up dust and debris. Not every thunderstorm, and not even every supercell, produces a tornado, which is why they remain relatively rare.

This article was written using information from Wikipedia.