Tornadoes

 
NOAA 		  What is a Tornado
The tornado is the most violent storm on earth for its size. The word tornado comes from the Spanish word “tornada” which means “thunderstorm”. A tornado is a violently rotating air column expended to the ground from a thundercloud. The strongest tornadoes can sweep cars, destroy houses, lift a whole train wagon from its tracks. Their rotational speed can vary from 480 kilometers per hour to occasionally 800 kilometers per hour and even faster.
 		      
             
      Detection
Tornadoes have a unique radar signature. It is called hook echo and has been known about since April 1953 when the ISWS (Illinois State Water Survey) found the distinctive difference between a regular storm and a tornado. Using radar to detect tornado activity allows the National weather service to give advance warning of an approaching tornado.
 		  
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Formation
Many tornadoes develop in a special type of thunderstorms called “supercell”. Supercells are thunderstorms that are 10-16 km in size and rotate. They life is very long – they may last several hours and can travel hundreds of miles and produce more than one tornado or a sequence of tornadoes. That's why what seems to be a long damaged path of one tornado may in fact be the result of another tornado's formation in the same place the tornado died. Supercell storms can produce other types of weather disturbances besides tornadoes. Supercell storms' isolation from other thunderstorms allows them to have more energy and moisture. However tornadoes may be created due to a wide variety of reasons.
 

      
             
      Occurrence
Tornadoes occur mostly in the USA . As many as 1100 tornadoes for one year were reported in 1973. However tornadoes occur in other countries too. In Australia for instance there are reports of several hundred per year. Other countries in which tornadoes occur are Great Britain , Canada , Germany , Japan , Italy , France and China .
 		  
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Fujita Scale
F4 207-260 km/h: Devastating damage. Whole frame houses leveled, leaving piles of debris; steel structures badly damaged; trees debarked by small flying debris; cars and trains thrown some distances or rolled considerable distances; large missiles generated.
 

      
     

 

      
     

Safety Measures
Humans are powerless to prevent a tornado from being generated. What a person can do is to be prepared for the case of such violent storms. These are some of the things a person should do to prevent a possible undesirable end.
 

  
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