京津冀一次区域性暴雨特征分析

利用FNL再分析资料、卫星资料和自动站资料对2019年7月22~23日京津冀一次区域性暴雨过程进行了环流形势、卫星云图、动热力结构的分析。结果表明:此次暴雨发生在500hPa两槽一脊、副热带高压北抬、低空急流的大尺度环流背景下。西南方向的水汽输送和黄渤海的补充水汽为暴雨提供了良好的水汽条件,在河北中部的水汽辐合抬升则为暴雨提供了抬升条件。此次暴雨的产生受中尺度对流云团的连续生成合并影响,降水效率高。在暴雨中心整层表现为低层辐合、高层辐散,上升速度中心明显,使得高层的抽吸作用更强,更有利于上升运动的维持与发展,为降水强度增大提供了有力的动力条件,高空弱冷空气的入侵对能量锋区不稳定能量的释放起到了触发作用。

Characteristics of a Regional Rainstorm in Beijing,Tianjin and Hebei

This paper uses the FNL reanalysis data,satellite data and automatic station data to analyze a regional heavy rain process in Beijing,Tianjin and Hebei from July 22-23,2019.The results show that the heavy rain occurred in the background of the large-scale circulation of 500 hPa with two troughs and one ridge,the northward rise of the subtropical high and the low-level jet.Water vapor in the south provided the conditions for heavy rain.The occurrence of this heavy rain was affected by the formation and consolidation of convective clouds.In the heavy rain center,low-level convergence and high-level divergence are more conducive to the maintenance and development of the upward movement and provide a powerful driving force.The invasion of weak cold air at high altitude triggered the release of unstable energy.