广东前汛期一次锋前暖区暴雨触发机制分析

An Analysis of the Triggering Mechanism for a Warm-sector Frontal Heavy Rain in Guangdong in the Annually First Rainy Season

利用ECMWF的ERAdata再分析资料、Micaps实况等数据,对2015年5月22—24日的广东大范围强降雨过程进行分析,结果表明:该次过程是一次典型的华南前汛期降雨过程,过程中存在明显的两种性质降雨,即粤西北由南支短波槽、低涡、切变线造成的锋面型暴雨,而珠江口及其东侧的暖区暴雨主要是由西南低空急流脉冲引起的;珠江口及其东侧的暖区暴雨的触发机制主要为中尺度能量锋、地面辐合线以及地形等。

Using the data of ERAdata reanalysis from the ECMWF and the observations of Micaps, an extensive heavy rain that happened on May 22-24, 2015 is studied. The result is shown as follows. The weather was a rain process typical of the annually first rainy season in the south of China. It was made up of two kinds of rain, the one in northwestern Guangdong was caused by a shortwave trough in the southern branch of the westerlies, a low vortex and a shear and the other over the Pearl River Delta and its eastern area was a warm-sector heavy rain resulting from the pulsation of a southwesterly low-level jet stream. The triggering mechanism for the latter was mainly a mesoscale energy front, a surface convergence line and the terrain.