NUMERICAL SIMULATION OF PRECIPITATION IN THE EASTERN TIBETAN PLATEAU WITH LASG MESOSCALE MODEL AND ITS OPERATIONAL APPLICATION EVALUATION

The sensitive numerical simulating study and the quasi-operational experiment are made on heavy precipitation over the eastern Tibetan Plateau by means of the LASG η-coordinate area-limited mesoscale model with different schemes, and the results are evaluated according to the related regulations of the Chinese Meteorological Administration. The comparison and analysis indicate that the weather systems in the low latitudes with active features have important influence on the quantitative and fix-point precipitation prediction; in the same way, the effect of methods for processing physical processes and topographic influence on the precipitation prediction varies greatly with different weather processes. Through emphasizing the influence of the closest station to the grid point, the extremes of high and low-value systems are retained by using appropriate objective analysis methods, so to improve the forecasting performance. The quasi-operational experiments indicate that with the relatively perfect dynamic frame and the processing methods of physical processes, the LASG η-model performs well in such areas with a complicated topography and highly varied weather systems, especially in the clear-rainy forecast. Moreover, the model can be used to make reasonable forecast in some different cases.