A tropical storm is storm system that consists of a low pressure center with numerous thunderstorms embedded in it. These thunderstorms can produce very high winds and cause large waves that result in major beach erosion for coastal areas effected by the storm. The winds speeds near the surface range from 63 to 119 km/h(39 and 74 mph).
A tropical storm begins as a depression. As a depression, its wind speed at the surface is less than 63 km/h. Most tropical storms occur over warm tropical oceans. The hot air will rise, creating an area of low pressure. The hot air travels across the warm ocean as it moves inward toward the low pressure area. The hot air then begins to pick up moisture.Thunderstorms begin to develop, due to the rising, moistened hot air.
The water vapor in the air condenses to form clouds and rain. As the water vapor condenses it releases energy. This energy is called Latent Heat, or heat of condensation. A storm is a type of heat engine. Latent heat powers a storm and intensifies it. A storm will intensify, as long as there is warm, humid air flowing around the center of the low pressure. This will attract more air. Typically, a tropical storm will not have an eye or clam center in the middle. The change of wind speed and and direction with altitude,(wind shear), must be low so that the heat from the thunderstorms stays in the center of the tropical storm.
The Earth’s rotation will also effect air movement. The Earth’s rotation deflects air from left to right in the northern hemisphere and from right to left in the southern hemisphere. As the air moves toward the center of the low pressure, the deflection causes the air to spiral around the center, rather than travel straight into the center. This inward spiraling of air causes bands of thunderstorms to form in the circulation. This is a distinct feature of a tropical storm, accompanied by the spiraling winds. The spiraling winds grow strong as they near the center of the low pressure. Centrifugal force, forces the rotating air towards the outside of the storm. This force makes it very difficult for the air to reach the center of the storm.
As the storm intensifies, it gains strength to the point where air can no longer reach the center. The storm then begins to form an eye-wall. This eye-wall is where the spiraling winds are concentrated the most. Inside this ring of spiraling winds, a calm area develops. This calm area is known as an eye. The major distinction between a hurricane and a tropical storm is the development of an eye. The eye generally forms when the wind speeds in the center of the tropical storm reach over 119 km/h(74mph)
Tropical storms do not occur 5 degrees latitude north or south of the equator. In the equatorial region the winds can travel straight in the center of the low pressure system and destroy it. This keeps any clusters of thunderstorms from developing into a tropical storm. Tropical storms do not occur in the south Atlantic Ocean due to cold ocean water temperature and high wind shear. For this same reason, tropical storms do not develop in the south Pacific ocean.
Once a tropical storms reaches cool water, it will eventually decrease in intensity and eventually die. This is due to the fact that they lose the hot humid air that is needed for growth.Once a tropical storm hits land, it dies off very quickly because it loses the evaporation of the warm ocean water.
