Tornado

About Tornado:

• It is a land-based vertical column of violently rotating air that forms from a thunderstorm to the ground. It can have wind speeds in the range of 105-322 km/h. The tornado over the sea is called waterspouts.
• The rotating column is physically connected to the cloud base or wall cloud and is often visible as a cloud-filled "condensation funnel". If the air is dry enough, the tornado may only appear as a swirl of dirt on the ground without a visible connection to the cloud above.
• Formation: Any collision of warm, moist air with dry, cool air in the presence of a low pressure system like a trough causes thunderstorms and tornadoes.
• Geographical distribution:
  • It occurs most commonly on continents in the mid-latitudes (between 20 and 60 degrees north and south), where they are frequently associated with thunderstorms that develop in regions where cold polar air meets warm tropical air.
  • They are the most common in the United States, Argentina and Bangladesh.
• The Enhanced Fujita scale is used to measure tornado strength. It is used to assign tornado a 'rating' based on estimated wind speeds and related damage.