Hurricanes space the many violent storms top top Earth. People call these storms by various other names, such together typhoons or cyclones, relying on where lock occur. The clinical term for all these storms is tropical cyclone. Just tropical cyclones that type over the Atlantic s or eastern Pacific s are dubbed "hurricanes."

Whatever they room called, tropic cyclones all kind the exact same way.

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Tropical cyclones are like huge engines that use warm, moist air as fuel. The is why they form only over warm ocean waters close to the equator. The warm, moist air over the s rises upward from close to the surface. Because this air moves up and away from the surface, over there is less air left near the surface. Another method to say the very same thing is the the heat air rises, resulting in an area of lower air pressure below.


A cumulonimbus cloud. A dry cyclone has so many of these, they type huge, one bands.

Air from surrounding locations with higher air pressure pushes in come the low pressure area. Then the "new" air becomes warm and moist and rises, too. As the warmth air continues to rise, the neighboring air swirls in to take it its place. As the warmed, moist air rises and cools off, the water in the air develops clouds. The whole system the clouds and wind spins and also grows, fed by the ocean"s heat and water evaporating native the surface.

Storms that type north of the equator rotate counterclockwise. Storms south of the equator rotate clockwise. This distinction is due to the fact that of Earth"s rotation top top its axis.

As the storm device rotates faster and faster, an eye creates in the center. It is an extremely calm and also clear in the eye, with an extremely low air pressure. Greater pressure waiting from over flows down into the eye.


If you might slice right into a tropic cyclone, it would certainly look something favor this. The tiny red arrows display warm, moist air rising from the ocean"s surface, and also forming clouds in bands approximately the eye. The blue arrows display how cool, dried air sink in the eye and between the bands the clouds. The large red arrows present the rotation of the rising bands that clouds.

When the winds in the rotating storm reach 39 mph, the storm is dubbed a "tropical storm." and also when the wind speeds reach 74 mph, the storm is officially a "tropical cyclone," or hurricane.

Tropical cyclones commonly weaken when they fight land, since they space no longer being "fed" through the power from the warmth ocean waters. However, they regularly move far inland, dumping numerous inches the rain and causing numerous wind damage before they dice out completely.

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Tropical cyclone categories:

Category Wind rate (mph) Damage at Landfall Storm surge (feet)
1 74-95 Minimal 4-5
2 96-110 Moderate 6-8
3 111-129 Extensive 9-12
4 130-156 Extreme 13-18
5 157 or higher Catastrophic 19+

The 2 GOES satellites keep their eyes on hurricanes native far above Earth"s surface—22,300 mile above, to be exact! (Learn an ext about this sort of orbit.)

These satellites, developed by and operated by the national Oceanic and also Atmospheric administration (NOAA), save resides by helping weather forecasters predict and warn people where and also when these significant storms will hit land.

Related sources for Educators

Our World: What is a Hurricane?Real World: Hurricane"s eye on excessive Weather