云南红河一次冬季大暴雨天气过程分析

利用高空常规气象观测资料、NCEP/NCAR逐6 h 2.5°×2.5°再分析资料、葵花-8红外云图、自动气象站观测数据,对2019年1月7~9日孟加拉湾热带风暴“帕布”影响云南省期间造成红河州暴雨天气过程的大气环流背景、水汽条件、动力条件、大气不稳定层结等进行分析。结果表明:这是一次由孟加拉湾风暴远距离影响造成的冬季大暴雨天气事件;南支槽前的西南气流能把孟加拉湾风暴产生的云和水汽输送到云南省红河州上空;700 hPa西南低空急流为此次天气过程提供了充沛的水汽供应;高低空急流耦合为水汽的垂直输送提供了良好的动力抬升条件;地形作用和对称不稳定是造成此次冬季暴雨天气过程的触发机制。

ANALYSIS OF A WINTER HEAVY RAINFALL WEATHER PROCESS IN HONGHE PREFECTURE,YUNNAN PROVINCE

Based on the high altitude conventional meteorological observation data,NCEP/NCAR 2.5°×2.5°reanalysis data for 6 hours,sunflower-8 infrared cloud image and automatic meteorological station observation data,the atmospheric circulation background,water vapor conditions,dynamic conditions,and atmospheric unstable stratification during the rainstorm process in Honghe Prefecture during January 7~9,2019 were analyzed.The results show that:This is a winter rainstorm event caused by the Bay of Bengal storm over a long distance.The southwest airflow in front of the southern branch trough can transport the clouds and water vapor generated by the Bay of Bengal storm over Honghe Prefecture,Yunnan Province.The southwest low level jet of 700 hPa provides abundant water vapor supply for this weather process and the coupling of high and low altitude jet provides a good dynamic uplift condition for the vertical transport of water vapor.Topographic action and symmetrical instability are the trigger mechanisms of the winter rainstorm process.