Characteristics of a Meiyu Heavy Rain System Simulated by High Resolution Limited Area Model

An experimental work first to transplant the High Resolution Limited Area Model (HIRLAM) successfully is performed in China.For the implementation, first of all is to re-adjust the coordination and to remove the inst ability caused by the Tibet Plateau.By the modifications, it can be smoothly operated in the middle and lower latitudes and the areas including the Plateau and the Changjiang Valley.Thus, this modified model is applied to simulate a torrential rain process which occurred in the Changjiang and Huie Valley in the Meiyu period in 1991.The simulation evolves the genesis, development and movement of a mesoscale system which had made the disastrous torrential rainfall and flood event.Futher more, by the comprehansive analyses of the high resolution atmo-physical parameters and the satellite images, it shows that the formation, construction, mechanism and intensity of the Tibet Vortics are quite different from the Southwest (Sichuan) Vortics.The latter are of comparatively weak raining system.On the other hand, we found that the Plateau System plays more effective role for the heavy rain event.The final result encourages us to use HIRLAM for the research and prediction of heavy rains in China.