How Strong Is That Hurricane?
The wind blows. The rain comes down. Hurricanes are powerful. They can rip a house apart. They can wipe out cities. But how do they start? And how do you know how big it will be? How can you tell how strong it is?
|Image above: Hurricanes form in water. The orange parts show where they form. Credit: NASA|
Let's figure it out.
Hurricanes start over the ocean. They need three things:
- Warm water
- Damp air
- Winds that meet
When the wind blows at least 74 miles an hour, it is called a hurricane. That is very fast! It is faster than a car drives on a highway. Sometimes the winds blow faster than that.
Parts of a Hurricane
There are three main parts of a hurricane:
- Eye -- This is the center. It is the calm part of the storm.
- Eye Wall -- This part is around the eye. This part has the strongest winds and rains. The winds may blow 200 miles per hour.
- Rain Bands -- These are the clouds that spin out and make the storm bigger.
How Strong Is It?
| Image above: There are three main parts of a hurricane.|
Hurricanes can destroy what they hit. The winds can blow things down. The water can cover homes. The rains can cause floods. We can know how strong a hurricane is. There is a scale that is used to measure them. It is called the Saffir-Simpson Hurricane Scale. A hurricane can be on a scale of one to five. A level one does not destroy as much as a level five does.
||Click on each picture |
to see the movies.
|One: There is not much damage.
|Two: The winds blow at about 100 mph; it may break windows and destroy trees.
|Three: It breaks windows and doors.
|Four: There is much damage.
|Five: This is the worst; winds blow at least 155 mph. It destroys buildings.
Adapted from Fierce Force of Nature: Hurricanes