A study of a coasting easterly wave

An application of a multi-level primitive equation model is presented here. The model physics include air-sea interaction, shallow and deep moist convection and long-wave radiative effects. An example of a prediction for a nondeveloping easterly wave is presented in this paper. It is shown that it is possible to obtain a reasonable prediction of the motion and intensity of the wave up to periods of around 72 hours. The calculations are extended to examine a number of important relevant topics such as: (i) the maintenance and energetics of the cold core disturbance, (ii) the restoring mechanism on the large-scale conditional instability of the tropical atmosphere during and after disturbance passage, (iii) the effects of differential long-wave radiation on the prediction, (iv) statistical equilibrium of the area of parameterized cumulus scale motions as a function of the larger scale motions, and (v) the importance of a simple parameterization procedure for short range prediction.