2019年6月10—13日河源市连续暴雨过程的诊断分析

A Diagnostic Analysis of a Persistent Heavy Rain in Heyuan City on June 10-13, 2019

利用常规观测数据、自动站资料、NCEP/NCAR FNL资料和多普勒雷达资料等,对2019年6月10—13日河源出现的连续暴雨过程,从天气形势、物理量场及雷达资料等进行诊断分析。结果表明:连续性暴雨发生在500hPa稳定维持两槽一脊、低纬有短波槽持续过境并伴有西南低空急流影响的环流背景下;低层没有明显冷平流,连续性暴雨过程发生在暖区中,强降雨与低空急流的脉动密切相关,暴雨落区与500hPa上升速度大值区相对应;西南、西北两支强回波带汇合形成的列车效应是造成强降水的主要原因,径向速度上存在明显的辐合区。

Using conventional observation data,automatic weather stations data,the FNL data from NCEP/NCAR and Doppler radars data,this paper diagnostically analyzes a persistent heavy rain that took place in Heyuan on June 10-13,2019 in terms of its associated weather patterns,physical quantities field and radar data.The result is shown as follows.The persistent heavy rain happened against a circulation background in which two troughs and a ridge were stable and persistent on 500 hPa,shortwave troughs pas-sed successively at low latitudes and a southwest low-level jet stream was present.There was no obvious ac-tivity of cold advection.The persistent heavy rain took place in the warm sector,closely correlated with the pulsation of the low-level jet stream.The area receiving the heavy rain was corresponding to the zone of large ascending velocity at 500 hPa.The main cause of this heavy rain was the so-called"train effect"that formed due to the convergence of two intense echo bands from the southwest and northwest,and there was a well-de-fined zone of convergence on the radial velocity.