How do severe storms and tornadoes form?

Compare the following storms for size, manner in which they form, wind speed, time for tornadoes and hurricane

• Answer:

  Hurricanes are fast, but tormadoes are faster, can't remember the speeds exactlym but I think hurricanes go to about 150-175 miles an hour, where tornadoes go to about 250-300. They are super fast. Formation: Hurricane: forms where water at temp 27 degrees C evaporates from the warm ocean / rising becuase of immense low pressure. Air comes in to take the place of the air which has risen and this causes wind. Air rises in a spiralling motion. The pressure gradient (ie the difference between the low pressure and the high pressure around it) will define how fast the wind is. Hurricanes move onto land and lose power, since there is no more water rising. Tornadoes. - something to do with 2 different air cells meeting. Warm from the south and cool from the north(????) not sure exactly) but when the 2 fronts meet, the warm air rises and once again, air replaces it, causing wind. It is suspected that the rising air intermingles with the jet stream which sets it spinning. Can't tell you much about time, but hurricanes form over a series of days and with satellite you can see them coming Tornadoes just arrive with little warning, and I think they last a few seconds - a couple of minutes - they destroy a much smaller area but what they do destroy they destry good and proper because they are so fast.