A cyclone is formed when a system of winds moving in circular motion closes in toward an area of the sea with low atmospheric pressure. The formation of cyclones occurs in four stages including formative, immature cyclone, mature cyclone and decay stage. Cyclones usually form in the eastern Pacific Ocean, southern Atlantic Ocean, Gulf of Mexico and the Caribbean Sea. A cyclone is usually accompanied by thunderstorms.
All coastal areas in the Atlantic and Gulf of Mexico are susceptible to cyclones. Some parts of the southwest United States experience thunderstorms and floods every year as a result of cyclones spawned off the Gulf of Mexico.
A cyclone may also be called a hurricane or typhoon depending on its place of occurrence. If it occurs in the Atlantic and North Pacific, it is referred to as a hurricane, and if it occurs in the Northwest Pacific, it is called a typhoon. Cyclones can cause extensive damage to coastal areas and miles inland. The powerful weather phenomenon can generate wind speeds of more than 155 miles per hour, in addition to microbursts and tornadoes.
The storm surges created by hurricanes can also cause catastrophic damage due to heavy rainfall. Notable destructive results of the strong winds include flying debris and floods.
Over land, powerful thunderstorm cells can cause warm and cold fronts to overlap, creating strong up and down drafts inside a storm. Unpredictable wind shear can start a rotation in the cloud layer, usually a horizontal one. At the same time, excess moisture creates a thick wall cloud extending down to the ground. Eventually, the mesocyclone in the clouds may be drawn down vertically due to the downdraft behind a strong cold front, wrapping itself in the wall cloud and becoming a tornado.