Development
Hurricanes do not instantly develop; they slowly build over an extended period. The initial stage of a hurricane is a tropical depression where a number of thunderstorms merge together with winds between 23 and 39 miles per hour. If proper atmospheric conditions are present a depression can evolve into a tropical storm where the wind speeds increase to 39 to 73 miles an hour. Tropical storms may begin to develop a circular shape, which resembles the outer appearance of a hurricane. If the tropical storm continues to intensify in speed and is measured at 74 miles an hour or faster, the storm is upgraded to a hurricane.
Water Temperature
Tropical storms and hurricanes develop over saltwater bodies where the surface or ocean temperature is 80 degrees Fahrenheit or higher. When these temperatures occur, normal wind gusts can pass through the waves causing water moisture to rise into the upper stratosphere. Once the moisture reaches the stratosphere the moisture can be cooled, which creates thunderstorm clouds. Rain begins to fall and it releases heat and energy.
Wind
As the heat and energy from a storm increases it causes a barometric pressure drop. This point where the barometric pressure drops the most can become the center of the storm, which is capable of pulling more wind and air into the system. As the wind increases it travels through the heated water and creates more and more thunderstorm clouds in a continuous cycle. The wind can rise to approximately 50,000 feet and can be forced outward to make room for more air as the cycle builds.
Rotation
The combination of blowing wind, warming water, rising water moisture and rain is subject to the Coriolis effect. This effect occurs in nature and causes the deflected wind to push to the right causing a spinning motion, which develops the characteristic rotation of the storm.