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Tornadoes!. Where do you go to see a tornado? Tornado Alley! Tornadoes are deadly serious. The deadliest in recent years killed 158 people in Joplin, Missouri in 2011. More than 550 people died in the US from tornadoes that year. The deadliest tornado on record killed 629 people in 1926.
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Where do you go to see a tornado? • Tornado Alley! • Tornadoes are deadly serious. The deadliest in recent years killed 158 people in Joplin, Missouri in 2011. • More than 550 people died in the US from tornadoes that year. • The deadliest tornado on record killed 629 people in 1926. • This “tri-state” tornado raced across Missouri, Illinois, and Indiana.
Tornadoes • Severe thunderstorms have a lot of energy and strong winds. • This allows them to produce tornadoes. • A tornado is a funnel-shaped cloud of whirling high winds. The funnel moves along the ground, destroying everything in its path. • As it moves, it loses energy. Before this happens, it may have gone up to 25 kilometers. • Fortunately, tornadoes are narrow. They may be only 150 meters (500 feet) wide. • Tornadoes are also called twisters. https://www.youtube.com/watch?v=cvOut9VUqKY
Classifying Tornadoes • The winds of a tornado can reach very high speeds. • The faster the wind blow, the greater the damage they cause. Wind speed and damage are used to classify tornadoes.
Tornado Alley • Look at the map. It shows where the greatest number of tornadoes in the U.S. • Tornadoes can happen almost anywhere in the U.S., but only this area is called “Tornado Alley”. • Why do so many tornadoes occur here? This is where warm air masses from the south run into cold air masses from the north.
Damage • A tornado strikes a small area. But it can destroy everything in its path. • Most injuries and deaths from tornadoes are caused by flying debris. • In the US, an average of 90 people are killed by tornadoes each year. • The most violent two percent of tornadoes account for 70% of the deaths by tornadoes. Tornado damage that occurred in the City of Murfreesboro, TN when it was struck by an F-4 tornado.
April 2011 • Late April 2011 saw the deadliest set of tornadoes in more than 25 years. • There were more than 150 tornadoes reported throughout the day! • Severe thunderstorms came about when two very different air masses met. • A warm moist air mass blew north from the Atlantic Ocean and Gulf of Mexico. • It rammed into a cold polar air mass that was sitting over the region. • In addition, the jet stream was blowing strongly in from the west. April 27-28, 2011. The cold air mass is shown by the mostly continuous clouds. The warm air mass is indicated by small low clouds. Thunderstorms are indicated by bright white patches.
Everyone in the region was told that tornadoes were possible. • But it’s impossible to know exactly where and when a tornado will touch down. • The path it will take is unknown, because tornado movement is not very predictable. https://www.youtube.com/watch?v=7T-5ByoKZO4 https://www.youtube.com/watch?v=Aj120i9w_dc
In Summary… • A tornado is a whirling funnel of air extending down from a cumulonimbus cloud. • The Fujita scale measures tornado intensity based on wind speed and damage. • Tornadoes can only be predicted over a wide region. https://www.youtube.com/watch?v=4agYIgqKvbg