Download Reading: The Formation of Hurricanes

Reading: The Formation of Hurricanes
Hurricanes are examples of severe weather systems that originate over the warm waters of the
tropical oceans along the equator. Hurricanes disperse the heat energy held in the warm ocean
waters. Tropical waters, warmed by the direct rays of the Sun, reach temperatures above 27° C (80°
F) to depths of over 36 meters (120 feet). The air above the water warms and rises, creating an area
of low pressure. The warm, moist, rising air cools and condenses, forming clouds and precipitation.
This process releases heat energy into the atmosphere. Cooler air moves in to replace the rising air
and generates winds. The low pressure area is called a tropical storm when wind speeds reach 39
mi/hr.
The weather system continues to grow in strength as the ocean
provides the energy, creating even lower pressure in the center of
the storm. The warmer the ocean, the greater the chance a
hurricane will form. Oceans with temperatures lower than 80° F do
not provide enough energy to fuel the hurricane. Clouds can reach
into the upper parts of the troposphere. However, upper
troposphere winds can shear off the clouds of a hurricane and
minimize or stop the hurricanes development.
As the air pressure within the tropical system decreases, the wind speed increases. The system is
called a hurricane when winds surpass 74 mi/hr. When hurricanes move onto land or into cooler
waters, they quickly lose their source of heat energy from the warm ocean water and die. According
to the picture below, where do most hurricanes form and travel?
If you said near the equator or in warm, tropical waters for question #1, you are correct!
Typhoon
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Cyclone
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Hurricanes
Cyclone
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