Forces of Nature Focus: Tornadoes Go to the following website: http://www.nationalgeographic.com/forcesofnature/ Read through the sections in order and answer the following questions. 1. What is a Tornado? A tornado is a ___________________________________ of air that extends from a thunderstorm to the ground. ________________-size hail might fall. A ______________ suddenly appears, descending from a cloud. The funnel hits the ground and roars forward with a sound like that of a ________________________________ approaching. The tornado tears up everything in its path. Every U.S. state has experienced twisters, but ___________________ holds the record: an annual average of ____________. 2. What Causes Tornadoes? The most violent tornadoes come from ____________________, large ________________ that have winds already in _________________. About one in a thousand storms becomes a supercell, and one in five or six supercells spawns off a tornado. Where do most tornadoes in the United States occur? ______________________________________________________________________. Why do most tornadoes form in the late afternoon? ___________________________________________________________________________ ___________________________________________________________________________. Tornadoes form when _______________, ________________, _________________ air. causing an updraft. _______________. ______________ air collides with The warm air rises through the colder air, This will begin to rotate winds very sharply in _______________ or Water droplets from the mesocyclone’s (rotating updraft) moist air form a ___________________________. This continues to grow and eventually it descends from the cloud. When it touches the ground, it becomes a ________________________. 3. Characteristics of Tornadoes Once a tornado hits the ground, it may live for as little as a ____________________ or as long as _____________________. Most don’t travel more than _________________ kilometers before dying out. Why are the measurements of tornadoes just scientists’ best estimations? ___________________________________________________________________________ ___________________________________________________________________________. Click the button to See Tornado Damage. List one piece of information for each tornado strength as measured by the Fujita Scale. F0 F1 F2 F3 F4 F5 4. What Damage Do Tornadoes Do? Every year in the United States, tornadoes do about _______________________ dollars in damages and kill about ___________people, on average. Winds can also destroy _______________, flip ________________, send ______________ and ________________ flying, tear ______________________from a riverbed. the bark off trees, and suck all the High winds sometimes kill or injure people by _______________________________________ or _____________________________________________. But most tornado victims are struck by flying debris – ____________________________, _________________________, _______________________, and ________________________________. 5. How Are Tornadoes Forecasted? Meteorologists at the U.S. National Weather Service use _____________________________, ______________________, __________________________, and _____________________________ to watch the skies for severe storms and tornadic activity. Doppler radars record ________________________ and identify ______________________________ within thunderstorms. Since Doppler radar has been in use, the warning time for tornadoes has grown from fewer than ___________minutes in the 1980s to an average of ____________ minutes today. When weather conditions are conducive for tornado formation, the ____________________________________ issues a tornado watch. When a tornado has been sighted or indicated on radar, a ______________________________ is issued. 6. Create a Tornado! Test out the different options to create a powerful tornado!