T42预报产品的预报能力与天气学分析

The Efficiency of T42 NWP Products and Synoptic Analysis in China

In order to understand the performance of T42 NWP and the efficiency of its products,the comprehensive analysis is made on the parameters obtained case studies of T42 prediction products in 1992. Meanwhile, the investigations on the evolution of the large-scale circulation and its adjustment are taken and the significant weather processes are taken into account. The results show that the 96-hour and 120-hour forecasts by T42 model are reasonably reliable for the motions of the atmospheric long wave and extra-long waves. They are considered to be valuable for the medium-range forecasting of the tendency and trend related to the evolution of the large-scale circulation. The model is better working in forecasting of the westerly belt circulation than in prediction of the subtropical circulation. However,the significant distortion appears when the model is used for forecasting of the southern frontal area and its formation and extinction. This is the key point when the model is improved.