Hurricanes are regions of low air pressure that form over
oceans in tropical climate regions. Hurricanes are large storms with revolving
winds. They form over the warm waters of the ocean when temperature and
pressure difference between the water and clouds is large. The clouds pull the
moisture and the air near the surface of the water up, toward the clouds, which
produces a column of fast-moving air.
At times, the air in one place is warmer than in another
place near it. Warm air is lighter and thinner than cool air. When cool heavier
air touches warm air, it presses against it and sets in motion. Some of the
warm air moves up and sideways. As the warm air keeps moving up and side and
out of the way, the cool air rushes in to take its place. This motion of the air
is the wind. Most of the air all over the surface of the earth is rotating.
Hurricanes may have a diameter of 400 to 500 miles (640-800
kilometers). It hit land with great force, bringing huge waves and heavy rain.
Many hurricanes cause severe flooding.