Where do hurricanes occur?
Hurricanes happen in warm places near the equator between the Tropic of Cancer and the Tropic of Capricorn. They never form on the equator itself.
Hurricanes that form in the Caribbean and the Atlantic Ocean occur between June 1st and November 30th each year. This is known as the hurricane season.
Why do hurricanes move in circles?
Because the Earth spins, the spinning movement causes the wind in a hurricane to go to the right. As the Earth keeps spinning the winds keep turning right. What would happen if you kept turning right?
Eventually, you would go around in a circle! This is what happens to a hurricane. The force that makes the wind turn to the right is called the Coriolis Force. The Coriolis Force does not affect winds above the equator.
Naming hurricanes
Have you ever heard of hurricane Katrina or hurricane Andrew? Just like people, hurricanes are given names too. At first, they were only given women's names but in the 1970s men’s names were also used.
The names are chosen in advance in alphabetical order by weather scientists. When they reach the end of the alphabet they start back again with another name beginning with the letter 'A'. Every 6 years the names are reused.
The names of very serious hurricanes that cause a lot of damage are not reused. This way they will be remembered in history.
Why are hurricanes dangerous?
When hurricanes hit land, they don't have the energy coming from the ocean anymore, so they slowly break up and die. This doesn’t stop them from causing damage, however.
When a hurricane reaches land it often produces a storm surge. This is when the strong winds from the hurricane push the sea toward the shore, causing water levels to rise and creating large waves. Some storm surges can reach 6m high!
Wind from hurricanes can also destroy homes and blow down trees.
Some of the worst hurricanes in history are the Bhola Cyclone which killed over 300,000 people in 1970, and hurricane Katrina which destroyed 80% of New Orleans in the United States.
Hurricane categories
Hurricanes are divided into 5 different categories of hurricanes depending on the speed of the winds.
Category 1: Up to 95 mph
Category 2: Up to 110 mph
Category 3: Up to 129 mph
Category 4: Up to 156 mph
Category 5: Anything over 157 mph. These hurricanes can cause huge disasters.
Fujiwhara effect
Have you ever wondered what happens when two hurricanes meet? Most people would think they join together to create one big storm but, instead, they dance around each other. This is called the Fujiwhara Effect. If both the storms are of a similar size and intensity, they can spin around each other before going on their separate ways. But if one of the storms is much bigger, it can absorb the smaller one.
Did you know?
- Hurricanes rotate in a clockwise direction in the Southern Hemisphere and in an anti-clockwise direction in the Northern Hemisphere.
- Today scientists have created technology that can predict the amount of storm surge that will affect coastal areas. These computer models are called Slosh Models.
