Transcript Tornadoes
By: Katie McHugh, Valerie Rozzo, And Kim Smethurst What is a Tornado? A tornado is a dark funnel-shaped cloud made up of violently rotating winds that can reach speeds of up to 300 m.p.h. The diameter of a tornado can vary between a few feet and a mile. What is a Tornado? Its track can extend from less than a mile to several hundred miles. Tornadoes generally travel in a northeast direction (depending on the prevailing winds) at speeds ranging from 20-60 m.p.h. What Causes a Tornado? Tornadoes are most often spawned by giant thunderstorms known as "super cells.” These powerful, highly organized storms form when warm, moist air along the ground rushes upward, meeting cooler, drier air. What Causes a Tornado? As the rising warm air cools, the moisture it carries condenses, forming a massive thundercloud, sometimes growing to as much as 50,000 ft. in height. Variable winds at different levels of the atmosphere feed the updraft and cause the formation of the tornado's characteristic funnel shape. Where Do Tornadoes Occur? Central and southern U.S., where warm, humid air from the Gulf of Mexico collides with cool, dry air from the Rockies and Canada. This area, dubbed "tornado alley," extends roughly from the Rocky Mountains to the Appalachians, and from Iowa and Nebraska to the Gulf of Mexico. Tornadoes can also occur elsewhere, though, including all U.S. states, Europe, Asia, and Australia. When do Tornadoes Occur? Tornadoes are especially common during the spring and early summer. May and June are the peak months in terms of numbers of tornadoes. When do Tornadoes Occur? April appears to be the deadliest month—an average of 27 tornado deaths occurred during this month between 1950 and 1999 One of the all-time worst tornado disasters occurred on April 3-4, 1974, when 148 twisters struck 13 states causing more than 300 deaths. What Kind of Destruction do Tornadoes cause? The Fujita scale classifies tornadoes according to the damage they cause. Almost half of all tornadoes fall into the F1 or "moderate damage" category. These tornadoes reach speeds of 73-112 m.p.h. and can overturn automobiles and mobile homes, rip off the roofs of houses, and uproot trees. What Kind of Destruction do Tornadoes cause? Only about 1 percent of tornadoes are classified as F5, causing "incredible damage." With wind speeds in excess of 261 m.p.h., these tornadoes are capable of lifting houses off their foundations and hurling them considerable distances. Ohio Tornadoes Miami County: 13 tornadoes F1, F2, F2, F1, F0, F1, F1, F1, F1, F1, F0, F1, F2 Montgomery County: 7 tornadoes F1, F1, F1, F3, F1, F1, F1 Ohio Tornadoes Greene County: 10 tornadoes F2, F2, F1, F1, F2, F3, F5, F1, F1, F2 F5 tornado occurred on April 3rd, 1974 killing 36 people and injuring 1150 people. Tornado Activity Materials: 2 bottles Water Oil Duct tape References http://www.infoplease.com/spot/tornado1.html El-Tigi, Manal, Ph.D. "Write a Lesson Plan Guide." The Educator's Reference Desk. 1 Dec. 1990. Information Institute of Syracuse. 15 Apr. 2009 <http://www.eduref.org/Virtual/Lessons/ Guide.shtml>. "Ohio Tornadoes 1950-1995." Tornado Project. 1999. Tornado Project. 15 Apr. 2009<http://www.tornadoproject.com/alltorns/ohtorn.htm#M>. Ohio Department of Education. Academic Content Standards-K-12 Science. 2004. page 182.