A trough or weak area of low pressure embedded within the tropical easterlies which is generally migratory (fast-moving) and without a defined cyclonic circulation.
A trough or cyclonic curvature maximum in the trade-wind easterlies. The wave may reach maximum amplitude in the lower middle troposphere.
A disturbance moving off the western coast of Africa toward the Caribbean and eastern North American coastal regions which may eventually develop into a hurricane.
A kink or bend in the normally straight flow of surface air in the tropics which forms a low pressure trough, or pressure boundary, with showers and thunderstorms. Can develop into a tropical cyclone.
Another name for an easterly wave, it is an area of relatively low pressure moving westward through the trade wind easterlies. Generally, it is associated with extensive cloudiness and showers, and may be associated with possible tropical cyclone development.
A hurricane goes through many stages as it develops. It starts as a tropical wave, a westward-moving area of low air pressure.
Tropical waves, also known as African easterly waves, are special types of easterly waves which are elongated areas of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of cloudiness and thunderstorms. Easterly waves can also form from the tail end of frontal zones in the subtropics and tropics. These easterly waves are not called tropical waves.