Cause Analysis of a Continuous Rainfall in Guangxi

doi:10.3969/j.issn.1673-7148.2012.01.005

Abstract：Based on the weather background, atmospheric circulation evolution and the meteorologi- cal conditions, including dynamic, thermodynamic, water vapor and so on conditions, the persistent torrential rain weather in Guangxi in June of 2008 is examined by using the observation data and NCEP reanalysis data. The results showed that during the course of the continuous heavy rainfall, 500 hPa circu-lation situation stable, high-altitude westerly trough continued deeline as a ladder and influence Guangxi, which constantly evoked heavy rainfall. The high-level wind speed dispersed in Guangxi at 200 hPa be- cause of Guangxi lied to the eastern ridge of high pressure zone in South Asia and exports of upper-level westerly jet right areas. Because of the reciprocity of the upper-low level jet, Southern China generatedpositive and negative of two vertical circulation and Guangxi converged ascending motion, which provided excellent dynamic force of heavy rainfall. The eruption of the South China Sea monsoon and the stably maintaining in low-altitude southern China of the subtropical high-pressure system offered water vapor continuously, which formed the Indian Ocean and the South China Sea two water vapor channels. In ad- dition, the high temperature and high humidity and high energy are the necessary thermal energy condi- tions for the generation of continuous heavy rain in Guangxi, which is propitious to the development and the generation of convective instability energy.