How does an African tropical wave turn into a tropical storm or hurricane?
Once the wave moves over the ocean, showers and thunderstorms often intensify. When this occurs, the surface air pressure drops and the wave becomes a strong low-pressure area. Sometimes the wave is so strong that it exits Africa as a closed low-pressure area, and then intensifies. Given enough time, and with persistent showers and thunderstorms, the wave transforms into a well-organized tropical depression, then a tropical storm and finally a hurricane. Our tropical cyclone glossary has more on this, as do our graphics on a typical hurricane’s life story and on why hurricanes form over warm oceans.
