Tropical Storm - Fascinating, Dangerous

For centuries, men and women have been asking one of the grand questions of life. Why do storms occur? Weather forecasters, storm experts and others have been studying storms for years and have uncovered some of the factors that contribute to a tropical storm. While much of the mystery has been eliminated, there are still a lot of unanswered questions about this phenomenon of nature.

One of the basic reasons for storm activity is that the atmosphere that sustains life on earth is constantly seeking a balance between warm air and cool air, between moist conditions and dry conditions, etc. When an excess of heat builds around the equator and tropical areas of the globe, that heat must be dissipated, generally to the latitudes slightly farther from the tropics. A tropical storm is nature's way of telling us something is out of balance.

Irene Hurricane

Born in the area of warm tropical waters, where surface temperatures of the ocean are usually above 80 degrees (Fahrenheit), tropical storms are the result of natural processes. When air and water vapor move upward (convection), clouds literally gather into thunderstorms. When this occurs at a certain distance from the equator, rotation can begin. This is the first sign of a different form of tropical weather - a hurricane.

The hurricane is the extreme version of a tropical storm. (They are also called typhoons and tropical cyclones, depending on where you are in the world.) In the presence of warmer water, a storm can intensify beyond the level of a tropical storm, primarily because of atmospheric instability and heat build up. When winds at upper levels of the atmosphere pull away rising air, the storm moves from the equator, rotating all the while. If the wind speeds remain between 39 and 74 miles per hour, the earth is experiencing a tropical storm. Should wind speed rise above 74, a hurricane is born.

The extremes of speed and rotation in a hurricane create a unique feature of this storm - the eye. Quite simply, the eye of a hurricane is very calm compared to the rest of these often-massive storms. The low pressure in this area creates clearer conditions than are found in the other parts of the hurricane, where thick clouds and strong winds are key features. Temperature levels vary within the eye as well, with cooler air near the surface of the ocean and warmer temperatures at higher levels. Scientists have found that this area of calm can vary in size from a few miles wide to a diameter of more than 100 miles.

While nature is seeking balance with tropical storms of all intensity levels, human beings continue to look for ways to prepare for these massive storms. One of the keys to this preparation is knowing when the highest wind speeds will arrive at a particular location. These destructive winds are found in the wall of the eye, so forecasters try to focus on when the eye wall will cross various geographical locations. While life on the planet may be negatively impacted by the destructive hurricane, all tropical storms are necessary to maintain a balance in earth's atmosphere.

Tropical Storm - Fascinating, Dangerous