What determines the path a tornado will take?
In its most familiar form, a tornado is a funnel-shaped, vaporous mass, with winds rotating around a vertical axis at high speeds, which reaches down from a thundercloud o a squall line. Violent storms often break out in central and southern states of the USA in springtime, when waves of warm, moist air from the Gulf of Mexico moving north and north-west, clash with invasions of cooler dry air coming down from the north and west. The month of May has the highest frequency of tornadoes, although April twisters tend to be more severe and take more lives. There are some 100,000 thunderstorms a year in the USA but only 1% spawn tornadoes. Of these, only 2% cause 70% of the deaths. A tornado takes its direction – usually from the south-west to the north-east- from the movement of the parent thunderstorm cloud. The funnel advances at forward speeds that average about 30 miles per hour, but may exceed 70 miles per hour. The tornado may bounce and skip, rising briefly from the ground and then
