2010-05-25宁夏暴雨诊断分析

Diagnostic analysis of a rainstorm in Ningxia May 25th,2010

利用常规气象资料、卫星云图及T213数值预报产品资料,应用天气学分析及诊断分析方法.对2010-05-25发生在宁夏的区域性暴雨过程进行了诊断分析.分析表明,高空急流的动量下传、高低空急流的适宜配置所产生的动力场的耦合作用为此次区域性暴雨的发生、发展提供了动力条件;此次暴雨过程充足稳定的水汽主要源自孟加拉湾和南海,是在有利的"东高西低"大尺度环流背景下,由200hPa高空急流5、00hPa西南中空急流、700hPa偏南低空急流、700hPa和850hPa低涡、切变线及地面"冷锋"共同作用造成的,暴雨落区位于地面冷锋前部、低空急流左前端.

Based on the routine meteorological data, satellite cloud photographs, numerical forecast products T213, applying synoptic analysis and diagnostic analysis methods, the heavy rain which was analyzed occun＇ed in Ningxia on May 25th,2010. The results show that the strengthening of a high-level jet stream and its momentum downward-spreading impelled the maintenance of the low-level jet, and the coupling of the high-and low-level jets provided a proper dynamical condition for the occurrence and development of the torrential rain process. The abundant and stable vapor supplied the rainstorm process which the vapors mainly came from the Bengal Bay and the South China Sea. The result came from common action of 200 hPa high-level jet, 500 hPa middle-level jet, 700 hPa and 850 hPa low-level jet,700 hPa and 850 hPa vortex, shear line and cold front surface, under the favorable weather conditions of the high pressure in the east and the lower in the west of this large scale circulating current. The strong rain falling position was in front of the cold front surface and the left front of low level jet stream.