淮北地区一次连续性暴雨的成因分析

Cause Analysis of a Continuous Rainstorm in Huaibei Region

利用各种常规资料,分析了2005年7月7-10日发生在淮北大面积连续暴雨、大暴雨天气过程的环流背景、发生机制及成因。本次大面积连续性暴雨的天气形势为两槽一脊型,旺盛的水汽在冷空气促发下形成了强烈的上升运动,中低层有很强的切变和暖湿平流,从而不断生成中尺度对流云团。此次移动性暴雨过程的前期由不断向东移动发展的MCS造成,后期降水则由低涡切变线产生的中尺度低涡引起。冷空气不断补充南下,副高西伸至淮河以南地区,冷暖空气在淮北地区交汇,且切变线稳定少动,是此次连续性强降水产生的主要因素。

Using the conventional information, the circulation background, mechanism, causes of a large - scale continuous rainstorm, hard rain weather process occurred in Huaibei region on July 7 -- 10, 2005 were analyzed. The large - scale continuous rainstorm is as two troughs with a ridge, a strong vapor which promoted by the cold air triggered a strong upward movement, and there is a strong shear and warm wet advection in middle and low level, so as to continuously generate mesoscale convective clouds cluster. The antecedent of mobility rainstorm process was caused by the continuing eastward movement of MCS development; the succedent precipitation was caused by the mesoscale low vortex which aroused by low vortex shear line. The main factors of the continuous heavy rainfall produced were cold air continuously supplied to southward, the subtropical high stretching westward to south of the Huaihe river areas, cold and warm air intersected in the Huaibei area, and the stabile shear line.