The clouds billow higher and form large masses of thunderstorms. Sometimes these storms will drift willy-nilly. Other times, the rising air helps form an area of low pressure and the storms develop in circular bands around that area of low pressure. That is known as a tropical cyclone. The tropical storm becomes a hurricane when the winds near the center, or eye, blow at over 74 mph.
Hurricanes can be several hundred miles wide.
The center, or hurricane eye, can range from a few miles to twenty miles wide. Usually, the wider and clearer the eye, the stronger the hurricane. As the strongest winds swirl along the edge of the eye, the air within the eye itself is usually calm, denoting the center of the low pressure powering the hurricane. Officially, hurricane season runs from June 1 through November 30 for the gulf coast and east coast of the United States. The prime time is mainly late August through early October.