Why do hurricanes form over water?

Question

please help ASAP

please and thanks

Answer 1

Land surfaces tear them apart.   It could start as a low over Africa but needs to move out into warm waters for development into a tropical storm.

Answer 2

http://www.srh.noaa.gov/srh/jetstream/tr...

Start here and go through the pages. I know it's in there.

Answer 3

The second poster is incorrect.  A tornado is a column of rotating wind descending from a cloud.  

A hurricane is defined by very strong winds and rain.

FYI, a tornado forming over the water is called a waterspout.

Answer 4

Hurricanes form over the warm tropical waters because the warm ocean water is the fuel for the storm. In fact, the water must be about 81 degrees F for hurricanes to thrive. There is a band across the globe near the equator called the Intertropical Convergence Zone or ITCZ, and this is the general area where hurricanes live.

There are several favorable environmental conditions that must be in place before a tropical cyclone can form. They are:

    * Warm ocean waters (at least 80°F / 27°C) throughout a depth of about 150 ft. (46 m).

    * An atmosphere which cools fast enough with height such that it is potentially unstable to moist convection.

    * Relatively moist air near the mid-level of the troposphere (16,000 ft. / 4,900 m).

    * Generally a minimum distance of at least 300 miles (480 km) from the equator.

    * A pre-existing near-surface disturbance.

    * Low values (less than about 23 mph / 37 kph) of vertical wind shear between the surface and the upper troposphere. Vertical wind shear is the change in wind speed with height.

Answer 5

If it formed over land, it would be a tornado. Tornadoes are spinning winds that gather up dust and dirt. Hurricanes on the other hand, form over the water, especially warm water, to gather the moisture from it.