贵州沿河县两次极端强降水的对比分析

Comparative analysis and numerical model test of two heavy rain processes in Yanhe County,Guizhou Province

利用常规天气资料、地面区域站、NCEP再分析资料和多普勒天气雷达资料对比分析了2016年6月19-20日特大暴雨和2019年6月22日大暴雨的天气形势、水汽条件、动力抬升条件以及雷达回波特征。分析发现:两次过程都属于典型的低涡切变型暴雨过程;"6·20"过程水汽通量强,辐合抬升高,维持时间长,是过程降水量大的主要原因;"6·22"过程水汽辐合强,垂直上升速度强,持续时间较短,是过程小时雨强大的主要原因;沿河西部的"列车效应"是这两次极端降水的关键原因;EC模式能够较好地预报出"6·20"过程中对流层中低层主要影响系统及其位置,随着预报时效的临近,预报的系统位置和移动与实况偏差减小。

Using regular weather data,ground regional stations,NCEP reanalysis data and Doppler weather radar data,the weather conditions,water vapor conditions and power uplift of the heavy rainstorm on June 19-20,2016 and the heavy rain on June 22,2019 were analyzed.Analysis found:Both processes belong to the typical low vortex shear storm process;The"6·20"process has a higher water content,The water vapor channel is built stronger and longer.However,the water vapor convergence of the"6·22"process is stronger,and the vertical ascending motion is stronger,Shorter time,this is a"6·20"process with large precipitation.And one of the reasons for the strong rain of the"6·22"process;The"train effect"along the western part of the river is the key reason for these two extreme precipitations;The EC mode can better predict the main influence system and its location of the middle and lower troposphere in this process.As the forecasting time approaches,the predicted system position and movement and live deviation decrease.