Here in Florida, hurricanes are as much a part of life as sunny beach days.
But as someone from a country where hurricanes are most definitely NOT a regular occurrence, I gotta tell you that these things are scary! These massive storms that travel thousands of miles across the globe and leave absolute destruction in their wake can seem like just another end-of-summer symptom, but why does Florida have to deal with this annual occurrence? What makes hurricanes always move toward the East Coast rather than the West Coast? And how the heck do they form?
So here we are to answer all your burning questions, as always!
Why does Florida have so many hurricanes?
How do hurricanes form?
Hurricanes occur in many places around the world, but they are limited to areas with very specific conditions. Some regions get affected by hurricanes frequently, such as Florida, Puerto Rico and the Gulf of Mexico, while some regions can go decades without even a wisp of hurricane winds.
Hurricanes are massive forces of nature that can build up from a humid breeze to a raging cyclone in days, but no matter where they are in the world and how big they become, they all start out with the same two ingredients: warm water and wind.
If we were to look at this map of hurricane paths around the world over the past 150 years, we’d be able to see pretty clearly that all hurricanes originate just north or south of the equator. Never on the equator, by the way, but we’ll get to that later.
Hurricanes need warm water that has a consistent surface temperature of at least 80 degrees Fahrenheit. This map of global sea surface temperatures shows us that those ideal water temperatures are right around the equator, and paired with the map of hurricane paths we looked at before, it’s easy to see why certain areas get hammered by hurricanes more than others.
These latitudes above and below the equator that contain that warm water are known as the tropics. The Tropic of Capricorn, located at about 23 degrees south of the equator, marks the southern latitude, and the Tropic of Cancer marks the northernmost boundary at 23 degrees north. Between these two tropic latitudes are the ideal hurricane-forming conditions.
So, why warm water?
Warm water evaporates much faster than cold water, and since the tropical regions are physically closer to the sun and receive considerably more direct sunlight than the rest of the world, it makes sense that that warm tropical water has a fairly high rate of evaporation during the peak summer months.
As a result, the air over this warm water is heavy with moisture. Hot air rises, of course, so we’re left with a constant stream of hot, moist air pouring up into the atmosphere. This hot, moist air is the fuel of hurricanes and what keeps them going, but even fuel on its own cannot power a hurricane. We need wind to turn it into a storm!
If warm water is the fuel of hurricanes, then wind is the machine that converts the fuel into the storm.
Let’s go to another map of the globe. In addition to our water temperature map that clearly shows the boundaries of the tropical regions, we also have this handy map of the trade winds that encircle the earth. On the map, you can see that the equator acts as the dividing line between the southeasterly and northeasterly trade winds that occupy their tropical regions to the north and south of the equator, respectively. These tropical winds, combined with the tropical waters, are what create hurricanes.
Unlike your daily gusts of wind and cool breezes that make up your city’s local weather patterns, trade winds are powerful winds that predictably blow from east to west. These trade winds form as sunlight heats the air around the equator and causes it to rise into the atmosphere. As the winds reach about 30 degrees north or south of the equator, they cool down and sink back to lower atmospheres, where they move toward the equator and gradually heat up again, creating a constant cycle of warm air.
As the Earth rotates “below” the atmosphere, the winds appear to move west. This is known as the Coriolis Effect, and it creates clockwise cycles in the northern tropics and counter-clockwise cycles in the southern tropics.
This effect, by the way, is why you’ll never see trade winds at exactly the equator! The Earth’s rotation forces the winds to blow to the north and south of the equator, leaving a small sliver of latitude practically wind-free! This area is called the doldrums.
So now we have warm water, hot air and cyclical winds all living together in the tropical regions. Quite literally, it creates the perfect storm.
Let’s go over hurricane formation step by step:
- As warm water evaporates, the hot air rises into the atmosphere as it heats and expands.
- Warm trade winds blow into that warm area and heat up, moving upward along the updraft of hot air.
- All that hot, rising air contains moisture from the ocean, which then condenses into clouds as it reaches higher into the atmosphere and cools down. This creates storm clouds.
- Storm clouds create storms, obviously, creating rain, thunder and lightning.
- Meanwhile, the constant updraft of hot air gets more and more powerful, sucking air up from the sea surface and funneling it high into the atmosphere.
- As all that moist air condenses, the hot air separates from the cool water and it continues rising higher into the atmosphere.
- Once the updraft of air gets high enough and the clouds form high enough into the atmosphere, the Coriolis Effect kicks in. The air and storm clouds begin to spiral around the center of the updraft.
Technically, a hurricane officially becomes a hurricane after winds reach speeds of 65 miles per hour or more, but the formation remains the same no matter the nomenclature.
As the Earth rotates under the storm, the now fully formed hurricane appears to ”move” west. The storm feeds on warm, moist water and travels along the paths of the trade winds that power it, which is why so many hurricanes follow the same path. It’s also why hurricanes always spin clockwise in the Northern Hemisphere and counter-clockwise in the Southern Hemisphere!
Where does Florida come in?
Go back to that map of global water temperatures and the map of the trade winds. Knowing what we do know about what hurricanes need to form and how they travel the way they do, it’s much easier to see why Florida is pummeled with hurricanes each year like clockwork. The warm water and humid air from the Gulf of Mexico and the Caribbean create the perfect fuel for storms, and the continents and land masses guide the storms up and along the coast of North America.
In the end, there’s obviously nothing we can do about the hurricanes that plow across the oceans to land on our luxury South Florida apartment doorsteps, but we can do our best to understand how they work and prepare accordingly. And who knows? Maybe knowing all this will help you understand all the weather jargon on the news the next time a hurricane threatens to visit!
Featured photo courtesy Pixabay/WikiImages