The Characteristics and Diagnostic Analysis of Guangdong Dragon-boat Rain in 2008

The article analyzes the long,wide-range,heavy rain precipitation which lasted in Guangdong Province from 28th of March to 18th of June in 2008.The results shows that the reason why theDragon-boat Rainformed is as follows:the large circulation in Eurasia middle and high attitudes which kept the stability of the two troughs and one ridge provided cold air for the lasting of the heavy rain;by east and south in the weak position of the subtropical high,the heavy rain kept sub-high with a little strengthening,which reinforced the wet warm air in South China;southern trough was active and coordinated with the westerly trough,high-level jet flow and south-pressing process of low-level shear line in every heavy precipitation; the vapor came from Bay of Bengal(mainly)and South China Sea,and the convergence of vapor mainly occurred in south coast;the ascension of the convergence in south coast provided a steady ascension background for continuous dragon -boat rain and it mainly appeared unstable stratification.