Презентация "Tornadoes" 8 класс

Подписи к слайдам:
TORNADOES There are many dangerous natural disasters in the world and tornado is one of them. It is defined as a whirling column of air or a funnel-shaped wind, formed in severe thunderstorms. Sometimes it’s called twister or cyclone and is regarded as the most violent of thunderstorms. If tornado touches the ground or body of water, it can cause lots of destruction. The main reason why tornadoes occur is the collision of warm air mass with a cool and dry mass. This leads to a powerful rotation of air, which can sometimes exceed 300 mph. The formed force of wind can lift and carry heavy things. Most often they happen in spring. A hot day in the afternoon or in the early evening is the most likely time for this dangerous storm. Large clouds appear in the sky. They become darker and darker. There are sounds of thunder in the distance. Bright flashes of lightning are seen cloud then forms a funnel and begins to twist.  Tornadoes can occur worldwide, but are often reported in the USA. Other countries that are frequently hit by tornadoes include Japan, Australia, South Africa, Uruguay, Canada. There are certain weather patterns that precede this natural disaster. For example, rain, strong winds, lightning, sometimes even hail or suspicious calmness. Tornadoes also happen over the seas and oceans.