"The air that surrounds Earth weigh 5 quadrillion tons. When it moves slowly, there's a breeze. When it blows very fast—74 miles an hour or faster—there's a hurricane. How does a hurricane begin? What should you do when you know a hurricane is coming? Franklyn M. Branley explains in a clear and simple way how these powerful storms get their starts, why they begin in warm places, and what you can do to stay safe when a hurricane is on the way." - jacket