A region of cloudy, relatively disorganized, weather in the tropics These sometimes develop into a tropical storm (and later into a hurricane).
Tropical cyclone that maintains its identity for at least 24 hours and is marked by moving thunderstorms and with slight or no rotary circulation at the water surface. Winds are not strong. It is a common phenomenon in the tropics and is the first discernable stage in the development of a hurricane.
A powerful storm that forms over water in the tropics or subtropics and holds its strength for 24 hours or more. As it gains power, it may become a tropical wave, tropical depression, tropical storm, or hurricane.