DIAGNOSTIC ANALYSIS ON THE DISTRIBUTION OF RAINFALL ASSOCIATED WITH TYPHOON “MOLAVE” (0906)

This work examines the mechanism of rainfall associated with typhoon Molave (0906) in Guangdong province and Guangxi Zhuang Autonamous Region with rainfall observations, radar mosaics from China National Meteorological Center and the final analysis data of National Center of Environmental Prediction (FNL/NCEP, USA). The result shows that the mechanism is different for the rainfall in the these areas. The rainfall in eastern Guangdong is mainly associated with a convective line to the front-right of the typhoon. The convective line is about 200 km away from the typhoon center. The rainfall in western Guangdong and Guangxi appear ahead of or to the left of the typhoon and is very close to the typhoon center. Both rainfall moves forward with the typhoon anticlockwise. It was also found that the rainfall occurred in the boundary between unstable and low-level convergent areas and closer to the convergent area. The unstable area is located in the downstream of rainfall and ahead of the convective line. It is an important factor to the development and convection. Strong frontogenesis is observed in the backward or upstream convective area of rainfall and is thus an important lifting condition for the formation of rainfall. When the low-level convergent area moves to the unstable area ahead of it, the unstable energy is left behind and as a result the convection is strengthened.