Tornadoes 2010

Tornadoes Rapidly rotating, funnel shaped cloud. Rapidly rotating, funnel shaped cloud. Most locally destructive of all storms. Most locally destructive of all storms. Usually touch the ground for only a few minutes. Usually touch the ground for only a few minutes. Wind speeds can be over 200mph! Wind speeds can be over 200mph!

Tornado Formation Develop in thunderstorms. Develop in thunderstorms. If the rising updraft in a thunderstorm changes direction, it can start to rotate. If the rising updraft in a thunderstorm changes direction, it can start to rotate. As this rotation tightens, it gets stronger but narrower. As this rotation tightens, it gets stronger but narrower.

Air Rotates Because of Wind Shear. How the column of air begins to rotate is not completely understood by scientists. How the column of air begins to rotate is not completely understood by scientists. Rotation appears to happen when winds at two different altitudes blow at two different speeds creating wind shear. Rotation appears to happen when winds at two different altitudes blow at two different speeds creating wind shear. This causes a horizontal rotation This causes a horizontal rotation

Faster Spin Makes a Funnel Cloud If this column gets caught in a supercell updraft, the updraft tightens the spin and it speeds up If this column gets caught in a supercell updraft, the updraft tightens the spin and it speeds up (much like a skater's spins faster when arms are pulled close to the body.) (much like a skater's spins faster when arms are pulled close to the body.) A funnel cloud is created. A funnel cloud is created.

The Funnel Rotates and Touches Down The rain and hail in the thunderstorm cause the funnel to touch down creating a tornado. The rain and hail in the thunderstorm cause the funnel to touch down creating a tornado.

Tornado Damage Tornado Damage Tornadoes are usually less than a 100 yards wide. Tornadoes are usually less than a 100 yards wide. The damage they inflict is severe but very localized. The damage they inflict is severe but very localized.

Fujita Wind Damage Scale This scale uses the damage to estimate the wind speed. This scale uses the damage to estimate the wind speed. The more severe, the less common. The more severe, the less common. F-5’s are the strongest, most damaging tornadoes. F-5’s are the strongest, most damaging tornadoes.

Tornado Safety Tornado Watch: conditions are favorable for tornadoes. Tornado Watch: conditions are favorable for tornadoes. Tornado Warning: Tornado has been sighted. Take cover if it is in your area. Tornado Warning: Tornado has been sighted. Take cover if it is in your area. Basements are the best place if there is a tornado. Basements are the best place if there is a tornado.

Tornado Alley The area over which tornadoes occur most often in North America is called Tornado Alley. The area over which tornadoes occur most often in North America is called Tornado Alley. It covers the Great Plains which is between the Rocky Mountains and the Appalachian Mountains. It includes all or half of the 13 mid-west states. It covers the Great Plains which is between the Rocky Mountains and the Appalachian Mountains. It includes all or half of the 13 mid-west states.

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