How do Hurricanes Form?Hurricanes are the most violent storms on Earth. People call these storms by other

names, such as typhoons or cyclones, depending on where they occur. The scientific term for all

these storms is tropical cyclone. Only tropical cyclones that form over the Atlantic Ocean or

eastern Pacific Ocean are called "hurricanes."

Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they

form only over warm ocean waters near the equator. The warm, moist air over the ocean rises

upward from near the surface. Because this air moves up and away from the surface, there is

less air left near the surface. Another way to say the same thing is that the warm air rises,

causing an area of lower air pressure below.

The air from surrounding areas with higher air pressure pushes in to the low pressure

area. Then, that "new" air becomes warm and moist, and rises, too. As the warm air continues

to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and

cools off, the water in the air forms clouds. The whole system of clouds and wind spins and

grows, fed by the ocean's heat and water evaporating from the surface.

Storms that form north of the equator spin counterclockwise. Storms south of the

equator spin clockwise. This difference is because of Earth's rotation on its axis.

As the storm system rotates faster and faster, an eye forms in the center. It is very

calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down

into the eye. When the winds in the rotating storm reach 39 mph, the storm is called a "tropical

storm." And when the wind speeds reach 74 mph, the storm is officially a "tropical cyclone" or

hurricane.

Tropical cyclones usually weaken when they hit land, because they are no longer being

"fed" by the energy from the warm ocean waters. However, they often move far inland,

dumping many inches of rain and causing lots of wind damage before they die out completely.

Adopted from: https://spaceplace.nasa.gov/hurricanesien/ (October 15, 2020)





Read the text and complete the following statements.



1. Storms consist of … over the ocean rising upward from near the surface.

2. Hurricane is the name of a storm that occurs ….

3. The air with high air pressure pushes in to … causing the storms.

4. The clouds are formed when ….

5. Higher pressure air from above flows down into the eye which is located in ….

6. … are formed when the speeds of the wind in the storm reach 74 mph.

7. There are two ways how …, clockwise and counterclockwise.

8. Tropical storms occur when the wind speeds in the rotating storm reach ….

9. Cyclones storms will gradually … when they leave the ocean.

10. Hurricanes cause lots of wind damage in land before ….​