Hurricane Dean: Why Storms Forming Off Coast of Africa Are Cause for Concern

As a resident of Central Florida, very few idioms command instant attention more than the word, "Hurricane." After being pummeled by the 2004 threesome of Charley, Frances and Jeanne, the mere utterance of the H-word sends shivers down the spine of the region.

Something that catches as much attention, though, is a phrase that is less immediately identifiable with the general American public. What central Floridians really don't want to hear is any news-station meteorologist saying, "We're closely watching a system off the coast of Africa." Worse than the H-word by tenfold, the A-word sends Floridians into a panic. Why would Floridians be concerned about the weather on the other side of the globe? Consider how a hurricane comes to be:

All hurricanes begin their life as a low pressure system. Some begin in the Caribbean, some form near South America and some even blossom in the familiar and comfortable Gulf of Mexico. The fiercest and most dreaded storms, though, are born of thunderstorms moving westward off the African coast. These storms maximize the amount of time and energy they have to develop into monsters before terrorizing their coastal victims.

Hurricane formation is basic grade-school science. Warm, moist air over the heated tropical ocean rises. In a perfect and stable environment, the warm air rises and is replaced with cooler air from higher atmospheres. When a thunderstorm is present, accompanied by its lower atmospheric pressure, the process changes. The warm air still rises, but with an increased vigor. This rising air further lowers the atmospheric pressure just above the ocean¡Çs surface.

This area of low pressure is an inviting destination for fresh air in surrounding areas of higher pressure. As this air rushes in, it also rises. The thunderstorm develops into an area of exceptionally lower than normal pressure and becomes a "depression."

Growing quickly, the tropical depression continues to feed on surrounding areas of high pressure (notably, the large area centered over the mid-Atlantic known as the Bermuda High), with new air continually sucked in and heated. As this warm air rises, it cools and returns to the surface, only to repeat the cycle. The Tropical Storm can, essentially, feed itself.

During the warm months of late summer, the tropical regions of the Atlantic ocean heat up to only a few degrees cooler than a standard American hot tub. This incredible concentration of heat energy in the ocean serves as food for the growing storms moving west off of Africa and into the Cape Verde region. As the storm slowly chugs along, the heat of the waters it crosses allow it to grow, expand, and become increasingly powerful by repeating the process described above.

When warm air on the higher pressure edges of the storm rushes in to the low pressure center, the one most prominent part of the hurricane is formed: Wind. As the air pressure at the center of the storm continues to fall lower and lower, the higher-pressure air at the edge of the storm rushes inward with increasing speed. In massive storms, the pressure has been known to be as low as 26.9 (inches of mercury). Air rushing into this incredibly low pressure produce wind speeds in excess of 155 miles per hour.

The damage caused by sustained winds of this speed is, for the uninitiated, unimaginable. A category five large hurricane can sustain winds of this speed for hours, completely obliterating most structures. For example, when Hurricane Andrew came ashore in 1992, elaborate concrete houses in Homestead, Florida were reduced to little more than their slab foundation. Everything else was, simply, gone.

With this level of destructive power, it is easy to see why Floridians jump to attention when a storm is brewing half a world away. The current monster of the Atlantic, Dean, formed just as described above. It began it's life as a mere "disturbance" off the western coast of Africa. Now, as it lumbers across the Caribbean, people in Mexico, Texas, Florida, Cuba and countless other countries are united in one hope: that this gift from Africa is not received.