What is a tornado? • Tornado - a rapidly rotating column of air descending from the cumulonimbus cloud or formed under the cumulonimbus cloud, often (but not always) visible as a funnel cloud. To be classified as a tornado, tornado should come from the clouds and touch the ground. It is known that a tornado can form an invisible funnel.
How tornadoes form? • Warm moist air from the Gulf of Mexico in the United States faces with cold air from Canada and dry air from the Rocky Mountains. Under such circumstances, there is a lot of thunderstorms, which are a threat of tornadoes. The most destructive and deadly tornadoes form under the huge cumulonimbus clouds, which in the U. S. is called supersells
At what time of the year there is the most tornadoes? • Most tornado season runs from early spring to mid-summer. In some states, peak tornado is in May, in others - in June or July. But in general, tornadoes can occur at any time of year.
What is Tornado Alley? • This is the historical name of the central American states that are experiencing the greatest number of tornadoes. However tornadoes can occur anywhere, and on the west and on the east coast of the U. S. , as well as in Canada and other countries.
As tornadoes in the northern hemisphere different from tornadoes in the southern hemisphere? • They differ in the direction of rotation. Most tornadoes (but not all) have a cyclonic rotation, ie, counterclockwise in the Northern Hemisphere and clockwise - in the south. Anticyclonic tornadoes in the northern hemisphere rotate clockwise. They occur most often in the form of water spouts, and there are many cases of simultaneous observation of cyclonic and
Why do tornadoes avoid centers of large cities? • Here all about probability. The city center is just a very small area compared to the area of the whole country. Therefore, the probability that a tornado hit the city center is very small. For example, the area of the central part of Dallas, only three square miles. However, and the city center can suffer from a tornado. So the St. Louis tornado in downtown occurred in at least four times.
At that resembles the sound of a tornado? • It depends on the size, intensity, distance to it and other factors. Most often compared to the sound of a tornado rumble of the train. Sometimes a tornado produces a sound similar to the sound of a waterfall, or the one that occurs when driving fast with the windows open.
What is the maximum wind speed that can be in a tornado? • No one knows. Immediately the wind speed can be measured only in weak tornadoes, because more powerful tornadoes destroy weather instruments. Maximum wind speed (about 512 km / h) was measured remotely using a mobile Doppler radar May 3, 1999 near Oklahoma City.
What is a tornado in the U. S. has claimed the most lives? • This tornado made the journey of 219 miles at a speed of 60 -70 miles per hour through the states of Missouri, Illinois and Indiana March 18, 1925. He was a category F 5 and killed 695 people.
Can a tornado move objects at great distances? • Yes, the tornado lifted into the air and carry debris and even heavy objects at distances up to several kilometers. The vertical component of the wind in a tornado pretty big to lift into the air even under heavy objects, especially if they have a large area, such as roof, wall, tree, or car.
When there was the highest number of tornadoes in a short period of time? • 3 and 4 April 1974 in 13 U. S. states at once flashed 147 tornadoes and another - in Canada. Killed 310 people in the U. S. , 8 - in Canada, 5454 people were wounded in the U. S. and 23 - in Canada. Seven tornadoes were classified as F 5 and 23 - rated as F 4.
Who study tornadoes? • For several decades, a leader in the study of tornadoes is the National Laboratory for the study of storms. It was she who had made a great contribution to the development of radar tornado had a large number of studies carried out
