How hurricanes form and maintain themselves. Why hurricanes are needed.
Hurricanes in the Atlantic, typhoons in the Pacific and tropical cyclones in the Indian Ocean are all one and the same. This is how they form and why the Earth and mankind need hurricanes.
All the time we see on the news the fluffy haired newscaster yelling things like hurricane Alice is now at category 4. We need to look behind those scenes at what’s really going on.
How Hurricanes Form
They form the world over about the same way. The hurricanes that strike the United States usually form in one of two areas, the Atlantic and sometimes in the Caribbean or Gulf of Mexico. Many times a hurricane will form as a cluster of thunderstorms moving west off of the western coast of Africa, near the Cape Verde Islands.
The thunderstorms gather around other thunderstorms and grow in a low-pressure area known as a tropical depression. The storms spin around this low-pressure area becoming stronger. By the time August arrives, the Atlantic Ocean has had all summer to heat up and the water is getting quite warm. Hurricanes thrive and grow when the water temperature is at or above 80F (27C). As this tropical depression becomes stronger by moving over hot and humid water, the air rises into the center of the storm feeding it and causing it to become stronger.
As the depression strengthens, the central pressure drops and the winds increase. When the storm deepens and the pressure or the barometric pressure drops enough, the winds will hit a certain velocity, the storm can then turn into a tropical storm, this is when they are first named.
The storm continues over open, hot and humid water and grows. It is the deepening or the lowering of the central pressure that causes the winds to increase. As the pressure continues to drop the winds increase in the center of the storm. When the winds hit 74 mph (119 km/h) they are then designated as a hurricane.
The storm will then churn across the open water until it hits land or colder water. The hurricane strength depends on two things now, the temperature of the water and if it remains over open water. Moving into colder water will decrease the strength of the hurricane and moving over land will decrease the storm. The type of land will also determine the degree to which the storm decreases, if it moves over flat, low ground it won’t lose much strength, but moving over mountainous terrain can weaken the storm considerably.
Once the storm crosses land and contacts water again, it will usually start to strengthen until it once again either enters into colder water or hits more land. The warm ocean water is what causes the hurricane to grow and sustain itself. That’s why when you look at a map of an approaching hurricane; the map will show the coastal water temperature. The warmer the water, the less likely the hurricane will dissipate much before landfall.
Hurricanes move erratically since there are so many factors guiding their movement. For example, a hurricane looks to be on a direct path and then it veers off. Hurricanes react with other weather forces such as cold fronts. If a hurricane is moving towards the US coast and then veers, many times the reason for this is a cold front moving off of the US coast which collides with the hurricane causing it to veer off path. Forecasters are getting better all the time predicting, but still hurricanes are sometimes just too erratic to be predictive with their paths.
Why Hurricanes Are Needed and Beneficial
Needed! I can hear the swear words right now from the Eastern and Southeastern US.
Hurricanes are good for the planet in that they cool things down. In this case a hurricane will redistribute hot air from one place to another. They move the hot air from the tropical regions to the more polar or northern latitudes. Like a circuit breaker, it keeps areas from overheating. Due to the upwelling of colder waters to the surface, the oceans cool. And the rain and cloud cover also contribute to this cooling left in the wake of a hurricane.
Hurricanes break droughts. So many times we hear of major droughts in certain parts of the world, such as Georgia or central Texas in the US being broken by a hurricane. Hurricanes might be thought of in a way as the world’s largest and most efficient desalinization plant imaginable. Taking salt water from the ocean through condensation and transporting this as fresh rainwater onto the land. Refilling reservoirs and underground aquifers. Which of course farmers, ranchers, cities and towns all need.
Some say that hurricanes are destructive to the land, yes in some ways they are. But the destruction is much like a forest fire by creating new. New sand bars for bird migration for example. Hurricanes do damage coral reefs such as in Florida. It was later found after Hurricane Andrew that the broken off coral reef actually formed a brand new coral reef.
Hurricanes are not to be taken lightly of course, but the next time the newscaster is yelling category 4, you can now look behind the scenes at what is really taking place.
Factoid About Atlantic Hurricane Names
Before 1953 Atlantic hurricanes were called by place names, dates or using military phonetics, then they started naming them with feminine names. In 1971 this was deemed unfair to females so they alternated between masculine and feminine names. In 1979, Hurricane Bob was the first male named hurricane.
Fly Through a Hurricane
To see and experience what it’s like to fly into a hurricane, there is an excellent show that flies into Hurricane Gilbert. They interview the pilots and scientists as they fly into Gilbert and record the lowest barometer ever for an Atlantic hurricane. The show is NOVA titled Hurricane! Dated 11/07/89. You can find it at or through your library or buy it through NOVA.
© 2009 Sam Montana