2021年8月牡丹江一次暴雨天气成因分析

Diagnostic Analysis of a Rainstorm Process in Mudanjiang in Aug 2021

利用常规观测资料、牡丹江自动观测系统采集的实况资料、NCEP再分析资料、FY-2G卫星TBB云图资料及牡丹江多普勒雷达资料,分析2021年8月21日牡丹江地区暴雨天气过程。结果表明:降水发生前,暴雨区水汽条件充沛,中低层辐合和切变线为强降雨发生提供了触发条件,低层辐合高层辐散有利上升运动加强,促进低层水汽的上升运动和不稳定能量释放。稳定的大气环流背景使云顶亮温(TBB)≤-42℃的中尺度对流云团在牡丹江上空长时间维持,强降水回波较长时间不断地生消,产生“列车效应”,是导致牡丹江暴雨的主要原因。

In this paper,the routine observation data,automatic observational precipitation,NCEP reanalysis data、FY-2G satellite TBB data and Mudanjiang National Weather Radar Station observation data are used to diagnose and analyze the rainstorm process in Mudanjiang region on 21.Aug.2021.The results show that:there is a strong water vapor transport belt over Mudanjiang before the rainstorm,and the low convergence and high divergence is beneficial to the enhancement of the ascending motion,triggering the release of unstable energy,leading to the occurrence of rainstorm.The rainstorm event is mainly caused by the continuous effects of the mesoscale convective clouds with TBB≤-42℃ in Mudanjiang.The strong precipitation echoes passing through continuously for a long time,whose train effect is the main cause of rainstorm.