Atmospheric disturbance in the tropical trade winds. Occasionally these systems intensify into hurricanes.
A wavelike disturbance in the tropical easterly winds that usually moves from east to west. Such waves can grow into tropical depressions.
a trough of low atmospheric pressure that is located in the tropical areas of the earth on ocean areas
A migratory wavelike disturbance of the tropical easterlies. It is a wave within the broad easterly current and moves from east to west, generally more slowly than the current in which it is embedded. Although best described in terms of its wavelike characteristics in the wind field, it also consists of a weak trough of low pressure. Easterly waves do not extend across the equatorial trough. To the west of the trough line in an easterly wave over the ocean, there is generally found divergence, a shallow moist layer, and exceptionally fine weather. The moist layer rises rapidly near the trough line; in and to the east of the trough line intense convergence, much cloudiness, and heavy rain showers prevail. This asymmetric weather pattern may be greatly distorted by orographic and diurnal influences if the wave passes over land areas. Easterly waves occasionally intensify into tropical cyclones. Compare equatorial wave.
An inverted, migratory wave-like disturbance or trough in the tropical region that moves from east to west, generally creating only a shift in winds and rain. The low level convergence and associated convective weather occur on the eastern side of the wave axis. Normally, it moves slower than the atmospheric current in which it is embedded and is considered a weak trough of low pressure. It is often associated with possible tropical cyclone development and is also known as a tropical wave.