山东一次局地大暴雨天气过程成因初探

摘要

Based on conventional meteorological observation data,NECP 1°×1° reanalysis data,precipitation data from automatic weather stations on the ground,FY2E satellite cloud images,and so forth,the circulation background,formation mechanism and features of a satellite cloud image of a local heavy rainstorm process in Shandong Province during August 8-9 in 2010 were analyzed.The results showed that the slow eastward movement of short-wave trough at middle and high latitudes,the stable maintenance of the subtropical high and ground cyclone,and the strong development of extra low-level southeast flow were large-scale circulation backgrounds of occurrence of the rainstorm;the rainstorm generated under the effects of mesoscale echo clusters or echo belts and mesoscale convective cloud clusters;precipitation mainly happened in periods when convective cloud clusters generated,developed and matured,and short-time heavy precipitation mainly appeared in the west,southwest and south of convective cloud clusters;extra low-level southeast flow was very conducive to the occurrence of short-time heavy precipitation;mesoscale convective systems rose in the whole troposphere,and the constant enhancement of low-level θse frontal zone provided favorable unstable energy for the occurrence of convective heavy rainfall.%利用常规气象观测资料、NECP 1°×1°再分析资料、地面自动站降水实况资料以及FY-2E卫星云图资料等资料,从环流背景、形成机理和卫星云图特征等方面,对2010年8月8日～9日山东区域暴雨局部大暴雨过程进行综合分析.结果表明:中高纬度短波槽缓慢东移,副热带高压和地面气旋稳定维持,超低空气流发展强盛,是暴雨发生的有利大尺度环流背景;在中尺度回波团或回波带及中尺度对流云团的影响下产生暴雨;降水主要出现在对流云团生成,发展、成熟时期,短时强降水主要出现在对流云团西部、西南部,南部;超低空东南气流由于水汽输送路径短,对短时强降水发生十分有利;中尺度对流系统表现在整个对流层为上升运动.低层θse锋区不断增强为对流性强降水发生提供了有利的不稳定能量.