Easterly waves are tropical weather systems that occur when a weak low-pressure trough develops in the
easterly wind circulation of the tropical zones, producing convergence, uplift, and shower activity.
Tropical cyclones can be the most powerful of all cyclonic storms. They develop over very warm tropical
oceans and can intensify to become vast inspiraling systems of very high winds with very low central pressures
and heavy precipitation.
Tropical cyclones form through a positive feedback between the ocean and atmosphere.
During their formation, convergence of warm, moist air at the surface causes uplift, which leads to
condensation, latent-heat release, and accelerated convection.
The convection in turn lowers surface pressures, which causes even more convergence of warm, moist
Tropical cyclones form in the summer and fall when the waters are warmest over the tropical oceans.
They can form in the central and westernAtlantic, the eastern and western Pacific, as well as the Indian