where and when do most tornadoes occur?

  The central part of the United States, known as the Great Plains, is suited to bring all of the things needed to form tornadoes. More than 500 tornadoes typically occur in this spot every year and that is why it is commonly known as "Tornado Alley". The Tornado Alley is in the spot were the cold polar air meets the warm tropical air, which forms tornadoes.
  Tornadoes occur at any time in the year but, mostly occur in April through mid-June.  In the southern states tornadoes occur in March through May. In the northern states it occurs during the summer. Tornadoes form during 3 and 9 p.m. but, some occur at all hours, day and night.

How tornados are formed?

 They usually form in a giant rotating thunderstorm called a supercell. Supercells develop in warm, moist air in advance of eastward-moving cold fronts.The result is great instability caused by the rising warm air. After that, clouds form together to give life to a tornado.  These thunderstorms often produce large hail, strong winds, and heavy rain.
   Tornadoes come in many shapes and sizes, but when they touch the ground they do lots of damage. When tornadoes hit the ground they rip thru buildings and throw debris and dust into the air.

What is the Tornado Alley?

  Tornado Alley is in the United States where tornadoes are most frequent. Tornado Alley is between the Rocky Mountains and the Appalachian Mountains. The land is the best breeding ground for tornadoes. The land in Tornado Alley is flat, which allows cold polar air to meet warm tropical air.
  The Tornado Alley includes parts of Texas, Oklahoma, Kansas, and Nebraska. That is why lots of tornadoes hit these states. That is what Tornado Alley is.