Tropical cyclone development requires a specific combination of favorable environmental conditions: warm ocean surface water (typically above about 26-27 degrees Celsius) to supply latent heat energy, moist unstable air in the lower-to-mid troposphere to sustain deep convection, weak vertical wind shear to allow the developing convective towers to remain vertically aligned and organize, and a sufficiently strong (non-zero) Coriolis force to initiate and sustain cyclonic rotation, meaning tropical cyclones typically cannot form very close to the equator where the Coriolis force approaches zero.