Atmospheric waves and the weather Waves A simple definition of a wave is a disturbance that propagates, carrying energy. In meteorology the discussion is usually about atmospheric waves of which two types are short waves and long waves. Long waves These persist for weeks and affect the weather over this period. They tend to be slow moving and can determine the underlying weather pattern for an extended period of time. Short waves These develop frequently and affect the weather over a short period of time. Computer forecasting models often pick up the development of them quite late and this can make them difficlut to forecast.