Hurricanes develop over warm tropical waters. Hurricanes begin to form as damp air rises from the surface of warm tropical seas. The sun heats the air and, as the air rises, there is a powerful updraft. This cools and turns into rain. The updraft is kept fueled as more hot moist air rises. The movement of the earth in an eastwardly direction pushes the moist air currents to one side resulting in hurricanes moving in a counter-clockwise direction.
Click on the link below for more information on how hurricanes are formed:
What are the phases of hurricane development?
A potential hurricane goes through four basic phases before it attains hurricane strength.
Phase 1 - Tropical Disturbance: A system in the trade wind easterlies which gives rise to a discrete area of cloudiness with embedded showers and thunder storms.
Phase 2 - Tropical depression:This system has definite counter-clockwise wind circulation in which maximum sustained surface wind is less than 61 km/h (38 mph).
Phase 3 - Tropical Storm: This phase immediately precedes the hurricane. Tropical storms are systems with definite counter-clockwise wind circulation in which the maximum sustained surface wind is greater than 61 km/h (38 mph) but less than 119 km/h (74 mph). It is at this stage the storm is given a name.
Phase 4 Hurricane:The final stage is the hurricane, with maximum wind speed of 119 km/h (74 mph) and over. The system is now mature and the eye is well defined. If atmospheric conditions are right, it can strengthen. This system has definite counter-clockwise wind circulation in which maximum sustained surface wind is less than 61 km/h (38 mph).
What are the different categories of hurricanes?
The Saffir-Simpson Hurricane Scale is used to categorize hurricanes based on their intensity. The Scale starts at 1, which is a minimal hurricane, and ends at 5, being a very strong hurricane.
Below is an easy to read chart that explains the basics of categorization: