The wind's picking up a bit...

Here's a short introductory video to hurricane formation:

Hurricanes, otherwise known as cyclones in the Northern Indian Ocean, or typhoons off the eastern coast of Asia, mainly form in the months of August, September and October. In the Atlantic, most of the major hurricanes are formed in what is termed the MDR (Main Development Region) which is situated between 10° and 20°N, so any changes in the temperature or atmospheric conditions in the Tropics can greatly influence rates of hurricane formation (Goldenberg et al. 2001).

Hurricanes are fuelled by heat, so in order to form, there needs to be a large expanse of ocean where the sea surface temperature (SST) is 26.5°C or above (National Geographic 2012). Hurricanes begin as tropical storm disturbances (Wu et al. 2006), and often remain at this status, but every so often these low pressure storm cells develop into the hurricane systems which can bring devastation. These formations occur when the ocean releases its heat into the atmosphere through latent heat transportation, which forms large cumulonimbus towers. When this tower expands into the troposphere, it is influenced by the converging anticyclonic winds which exist there, driving the storm system and transferring the heat release into kinetic energy. The larger the temperature differences between the ocean and the atmosphere, the larger the driving force for the hurricane.

One of the instantly recognisable features of the hurricane is the eye which resides in the centre of the storm. This warm core intensifies the upper anticyclone in the troposphere, in turn driving greater heat and moisture uptake from the ocean which feeds the storm further. Air is sucked into the low pressure system, rises close to the eye wall and is heated adiabatically whilst being uptaken to the troposphere; when it cools it then descends outside of the storm formation. This is known as a Carnot energy cycle and is known for its efficiency. The dry air descending from the troposphere (blown in from across the Sahara desert (Wu et al. 2006)) is drawn into the eye and heated, again adiabatically, to intensify the heat supply to the hurricane (National Geographic 2012).

According to Chorley et al (2010), the main driving forces for hurricane formation are:

• A large supply of heat and moisture from the ocean surface, as well as having a low frictional drag on the surface waters
•  The release of latent heat through condensation, which aids in forming the towering cumulonimbus clouds and also provides potential energy for kinetic movement.  
•  Divergent winds in the upper troposphere

Inhibiting factors include:

•        Decrease in SST or when the hurricane system makes landfall, as there is no further supply of heat energy which can drive the storm system.
•        Cold air can also be drawn into the vortex which again decreases the energy input into the storm system.
•        A strong vertical wind shear (such as an area beneath a Jet stream), as it is difficult for the vortex to form.

FURTHER REFERENCE:

Chorley, R.J. and R. G. Barry (2010) ‘Atmosphere, Weather and Climate (Ninth Edition)’, Routledge: New York.