There are several factors for a hurricane formation such as, tropical ocean water, heat from the sun, air, wind and the spin of the Earth. According to the steps of a hurricane formation. Firstly, Warm ocean water with the temperature of more than 26.5 degrees Celsius evaporates caused by heat from the sun and becomes warm moist air and rises up to causes the area the lower air pressure. Then, the air from surrounded area that has higher air pressure replaces the low pressure area to becomes new warm moist air and start rising up from the ocean just like early air. After that, while the warm moist air is rising up and swirling to replace, the temperature of the air above the ocean has drop and forms the clouds. Then, this system of clouds and wind rotate and grow because of the Earth’s rotation. So, they develop a tropical storm which the wind speeds reach 39 miles per hour. Finally, when the storm becomes stronger and the wind speeds increase up to more than 74 miles per hour, the storm is finally called "hurricane". 
Overall, this show how the hurricane is actually happens.