利用NCEP1×1、2.5×2.5资料以及常规观测资料,采用天气动力学诊断分析方法,对2015年11月7日-13日广西秋季连续性强降雨过程进行分析.结果表明:①强降雨前期、后期是两次华北槽引导两次低层切变线和地面冷空气南下造成,强降雨中期则是高原槽东移和切变线北抬南风加大辐合引起;②8日由于副高更强切变线只压到桂北,12日副高南退到沿海后切变线南压到桂南,且强度更强,造成的强降雨范围更大;③通过位势倾向方程分析发现,槽前的正涡度平流和冷平流随高度减弱使得副高北界出现两次南退;④锋生函数和假相当位温能够判断未来锋面走向从而预报强降雨的落区.%Using the information of NCEP1×1, 2.5×2.5 and conventional observation data, a process of continuous heavy rainfall occurred in autumn in Guangxi on 7 -13 November 2015 was analyzed. The heavy rainfall in early and late periods was caused by two low-altitude shear lines and cold air; in the middle period, the reason was the east movement of the plateau trough and convergence which was induced by the increasing south wind after a north lift of the shear line. On November 8, the shear line only moved to northern Guangxi due to strong Subtropical High. On 12, the shear line southward to southern Guangxi after the subtropical high retreated to coastal areas, inducing a wider range of heavy rainfall. Through the analysis of potential tendency equation, we found that the two southern retreats occurred in the northern boundary of the subtropical high because of the positive vorticity advection in the front of the trough and a cold advection decreasing with height. The function of frontogenesis and pseudo-equivalent potential temperature can be used to predict the future frontal trend and forecast the falling area of heavy rainfall.
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