what makes hurricanes to occur?

Answer 1

A tropical cyclone is a warm storm system fueled by thunderstorms near its center. It feeds on the heat released when moist air rises and the water vapor in it condenses. The term describes the storm's origin in the tropics and its cyclonic nature, which means that its circulation is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Stolen from http://en.wikipedia.org/wiki/Huricane

Answer 2

Follow up this reasoning:
The the air and water is hotter near the tropics because the sun is radiation is higher.
The air is much colder as you approach the poles.
The air is heavier when is colder and it gets lighter when it expands because of the heat.
The speed of the air is higher near the equator because is the higher distance toward the center of rotation.
Think now the earth like a big centrifuge in which the cold air, because is heavier, try to go to the equator and the warm air try to go the poles as its been squeezed by the cold air.
As the hot air travels to the north starts acquiring speed because as it goes north it gains momentum and also the earth speed is lower but the air still have the speed of the equator in it. The combination of this two factors allow the hurricane to acquire a lot of speed.

Answer 3

A hurricane or a tropical cyclone is a warm storm system fueled by thunderstorms near its center. It feeds on the heat released when moist air rises and the water vapor in it condenses. The term describes the storm's origin in the tropics and its cyclonic nature, which means that its circulation is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Tropical cyclones are distinguished from other cyclonic windstorms such as nor'easters, European windstorms, and polar lows by the heat mechanism that fuels them, which makes them "warm core" storm systems. Depending on their location and strength, there are various terms by which tropical cyclones are known, such as hurricane, typhoon, tropical storm, cyclonic storm, and tropical depression.

Tropical cyclones can produce extremely strong winds, tornadoes, torrential rain, high waves, and storm surge. They are born and sustained over large bodies of warm water, and lose their strength over land. This is the reason coastal regions can receive significant damage from a tropical cyclone, while inland regions are relatively safe from receiving strong winds. Heavy rains, however, can produce significant flooding inland, and storm surges can produce extensive coastal flooding up to 25 miles/40 km inland. Although their effects on human populations can be devastating, tropical cyclones can also relieve drought conditions. They carry heat away from the tropics, an important mechanism of the global atmospheric circulation that helps maintain equilibrium in the Earth's troposphere.

Answer 4

Circulating thunderstorms and convection