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2  Twisters  Funnel cloud  Waterspout Tornado Nicknames

3 A tornado is a violently rotating column of air extending from a thunderstorm to the ground

What Causes a Tornado? When a layer of cool, dry air floats over warm moist air, forming thunder clouds-- you have tornado conditions. The cool, dry air is more dense than the warm, moist air, but it doesn’t sink down because the warm air stays put. Some pockets open allowing some warm air to rise to the cooler air above The counter-clockwise spin of the low- pressure storm creates the vortex spinning by itself—a tornado! 4

Tornado Formation

Tornados form from thunderstorms which contain one or more updrafts (upward moving air which is warm and moist). These updrafts form towering cumulonimbus clouds which race upward and cool to form ice crystals (once they reach the anvil of the thunderstorm). Downdrafts of cold air aloft also occur as the thunderstorm intensifies. 6

Severe thunderstorms, which is an intense thunderstorm with winds of at least 60 mph, most likely produce tornados. A thunderstorm capable of producing a tornado requires key ingredients such as: warm moist air, cold air aloft, some kind of wind shear(provides vertical motion) and instability high in the atmosphere, and a trigger. Tornadic thunderstorms usually occur where cold fronts clash with warm fronts over the Southern Great Plains. (Tornado Alley) 7

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Where Do Most Tornadoes Occur in the U.S.? 10

11 CChange in wind direction IIncrease in wind speed IIncreasing height RRising air within a thunderstorm

12 Tornado damage is measured by the Fujita Scale.

13 Category Damage Wind F0 light 40–72 mph F1 moderate 73–112 mph F2 significant 113–157 mph F3 severe 158–206 mph F4 devastating 207–260 mph F5 incredible 261–318 mph

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15 Where do tornadoes hit in the United States? Where do most tornadoes hit in the United States? In the United States, the area where the tornadoes Tornado Alley hit the most is called Tornado Alley. The states which are in the tornado alley are:  Texas  Nebraska  Colorado  Iowa  Illinois  Indiana  Missouri  Arkansas Danger! Tornadoes!

16 Tornado Watch: A tornado watch is issued when conditions or the weather is right for a tornado to occur Tornado Warning: A tornado warning is issued when a tornado has been seen

17 Where is the safest place to go during a tornado?

What To Do? Listen to the radio or watch TV for weather updates. Tornadoes are hard to predict. You may only have a few minutes warning. Seek shelter if a tornado is coming your way. An underground shelter is best (basement or storm shelter). Or find an inside room or hallway or closet on the lowest floor away from windows. If you are outside and cannot get inside, lie flat in a ditch or ravine. Lie face down and cover your head with your hands. If you are in a car, take shelter in a nearby building. After a tornado, watch for broken glass and downed power lines. If people are injured, don’t move them unless they are in immediate danger. Call for help right away!

19 Number of Tornadoes in The Past 5 Years

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21 1. Name at least one tornado nickname. 2. Name one thing needed for a tornado to occur. 3. What is the name of the scale that measures tornadoes? 4. Which state is not in tornado alley: Texas, California, Nebraska, or Kansas? 5. What is it called when conditions are right for a tornado to occur? 6. Where is the safest place to go during a tornado?