Abstract:On review of the theories of wave-mean flow interaction and non acceleration, theorem, and the corresponding numerical analyses, the dynamical mechanism of variation of westerly index is discussed. It is pointed out that the first and active causes of the time variation of westerly index are tne internal forcing induced by wave-mean flow interaction and external forcing due to the existence of sources of momentum and heat, and its second and Passive-cause is the mean meridional circulation induced by the above-mentioned internal and external forcing. The possibility of forecasting westerly index by employing highly simplified dynamic systems is also discussed.

Abstract:A numerical method of statistical pattern recognition is proposed, it needn't assume that the predictand meets the requirement of certain distribution. A statistical relationship between the predictand and the predictor was obtained directly by computer from its practical distribution, and then the type of pattern was recognized. Compared with the usual analytic discriminatory method, the Predictive effectiveness is improved.In this method, the influence of transparence is better. Therefore, it is better to be used in the very short-range forecast, in which the relationship between cause and effect is more obvious.

Abstract:In this Paper, an objective method on classification of rain-belt in summer in the east Part of China was suggested and compared with that of eye-observation. The problem of rain-belt pattern forecasting was discussed, too.

Abstract:The regression expressions of principal forces in th'e motion equation were recalculated after enlarging of sizes of the samples relative to the Philosophy of the statistical-dynamic model (SD-75) for typhoon track forecast. Then a test on the operational forecasts of typhoon track in the 1987 typhoon season was carried out, using the revised model (called SD-85).The results indicate that the later is more advanced than the former in respect of prodictive characteristics.

Abstract:In this paper, the quasi-ge'ostrophic Q-vector analysis -method is introduced. B/ means of Q-vector analysis, we diagnosed a severe cbnvective storm episode (4-5 Augest 1987) in Liaoning Province and compared the diagnostic result with LFM Prediction. The results suggest that the Q-vector analysis can reveal the synoptic and sub-synoptic scale circulation change during the severe convection and provide some valuable information for local short range weather forecasting.

Abstract:In this paper, ,the regions, over the North Pacific, whose SSTs are signifi-cantly correlated with the winter wheat gibberellin in partial Jiangsu Province, the areas south to the Huaihe River, are determined using expansion method of EOF. SSTs of the significantly correlative regions are transformed into a few new factors repressing the main information of all the SST by means of the analysis of Principle components. Based on those factors the long-range Prediction model are given and the Prediction are obtained.