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SAI International School
                                                     Class VII
                                                 Lesson Notes
                                               Subject: Physics
                                       Ch-Wind, Storm and Cyclones
                                              Subtopic: Tornado
           Tornado:
           A twisting funnel of violently spinning wind with its narrow end towards the land is known as a
           tornado.

           It is formed when column of cold air, funnel like in shape sinks from a storm cloud
           (Cumulonimbus cloud). The air from the Earth’s surface, which is comparatively warm, rises up
           and starts revolving around the cold air column with a very high speed swirling wind.























           Tornadoes wind speed can reach up to 500km/hr. It can occur anywhere when conditions are
           right.
            Most tornadoes are found in the Great Plains of the central United States – an ideal environment
           for the formation of severe thunderstorm.
            In this area, also known as Tornado Alley, storms are caused when dry cold air moving south
           from Canada meets warm moist air traveling north from the Gulf of Mexico.
           They are most common in countries like USA, but they hardly occur in countries like India.

           Safety precautions:
           During Tornado, we should take following precautions:
              1.  Go to the lowest and smallest room, preferably to the basement.
              2.  Get under something sturdy or in a hallway.
              3.  Get away from windows.
              4.  Cover yourself from blankets, pillows and coats to protect you from debris.
              5.  Crouch as low as possible to the floor.
              6.  A bathtub may also offer a shell of partial protection.
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