Formation
Before a tornado forms, the conditions have to be perfect for one. A storm brews up, usually a supercell. Supercell storms can be quite dangerous themselves, with large hailstones and high speed winds. It is from this type of storm that tornadoes can be formed.
First, huge amounts of air are raised up by the wind, at about 5,000 ft per minute (This is extremely fast. To compare, a high speed jet only rises at 3,000 ft per minute.). This air forms a cloud. The wind then brings condensation, a by-product of the supercell, to the cloud, increasing its size. With the help of high winds, the condensation in the air begins to spin, making a vortex. This brings a spinning column down. This is called a mesocyclone.
After the mesocyclone is formed, cold, dry, sinking air starts to wrap around the back of the mesocyclone, forming what is called a rear flank downdraft. This creates a temperature difference, which introduces an instability that allows the tornado to thrive. The bottom of the mesocyclone becomes tighter, which increases the tornado's speed. The funnel of air starts to descend to the moist cloud base. It sucks it in it into a spinning wall of cloud. Only then when it touches the earth's surface is it considered a tornado.
When the moisture in the air dries up, or the temperature difference regulates and becomes stable again, the storm loses momentum and draws the tornado back inside.
First, huge amounts of air are raised up by the wind, at about 5,000 ft per minute (This is extremely fast. To compare, a high speed jet only rises at 3,000 ft per minute.). This air forms a cloud. The wind then brings condensation, a by-product of the supercell, to the cloud, increasing its size. With the help of high winds, the condensation in the air begins to spin, making a vortex. This brings a spinning column down. This is called a mesocyclone.
After the mesocyclone is formed, cold, dry, sinking air starts to wrap around the back of the mesocyclone, forming what is called a rear flank downdraft. This creates a temperature difference, which introduces an instability that allows the tornado to thrive. The bottom of the mesocyclone becomes tighter, which increases the tornado's speed. The funnel of air starts to descend to the moist cloud base. It sucks it in it into a spinning wall of cloud. Only then when it touches the earth's surface is it considered a tornado.
When the moisture in the air dries up, or the temperature difference regulates and becomes stable again, the storm loses momentum and draws the tornado back inside.