The statement that a tornado is believed to be caused by two levels of rotating air traveling in different directions and/or speeds is true. Correct answer: A This funnel-shaped windstorm of air extends from a thunderstorm to the ground. When cold,dry air mass meets warm,moist air mass, they create instability in the atmosphere.Once the air begins to rise and becomes saturated, it will continue rising to great heights to produce a thunderstorm cloud, if the atmosphere is unstable