Tornadoes are columns of air that spin at a high rate of
speed. They are small in scale but can be very violent. The area affected
by a tornado's passage is between about 40 and 400 metres in width and between 1.7 and
36 kilometres in length. During a tornado the damage is due to wind as well
as an extremely sudden drop in pressure. Tornadoes vary in intensity, measured
on the Fujita or F scale, graduated from 0 to 5 based on the level of damage.
The main season for tornadoes is from April to October, and every province is
subject to the risk of tornadoes.
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