Short waves have smaller amplitude, wave length, and duration than long waves. They move in the same direction as the larger current in which they are found. They may cause instability by inducing upward vertical motion of air in front of them. They are more numerous than long waves and often disappear at greater altitudes in the atmosphere.
A short wave trough or a broad trough at 500 mb over the local area will increase convective activity. Short wave or broad troughs have a tendency to produce lines rather than areas of convective activity. Longer periods of convective activity are observed during this synoptic situation.