摘要
利用广州市双偏振多普勒雷达、广东省自动气象站及Micaps常规资料对2020年5月22日发生在广州及东莞的特大暴雨进行分析,结果表明:(1)该次过程出现在高空槽后西北气流中,低层的低涡切变线配合低空急流仍具有强的辐合抬升作用,在充沛水汽背景、弱冷空气的触发下出现局地性特大暴雨;(2)弱冷空气分别向南及西南扩散先后触发多单体风暴,在高空西北气流引导下以西北-东南传播,路径顶端的单体最早成熟,新生的单体因旧单体形成的冷池驱动而不断发展,造成高组织化的后向传播特征,列车效应式的回波造成局地特大暴雨;(3)这是一次低质心、高降水效率的多单体风暴过程;中尺度径向辐合特征利于单体强度维持或发展;(4)同样的反射率值时,K_(DP)大说明降水更强,对判断雨强有参考意义。
Using the data from a dual⁃polarization Doppler radar in Guangzhou,observations from auto⁃matic weather stations in Guangdong province and conventional data of Micaps,this work analyzes an unusu⁃ally hard rain that happened in Guangzhou and Dongguan on May 22,2020.The results are shown as fol⁃lows.(1)The rain studied was local and unusually heavy,which took place under the background of abun⁃dant moisture and triggered weak cold air as a low⁃level vortex shear was coupling with a low⁃level jet stream in the northwesterly in the rear of an upper⁃level trough,which still had strong converging and lifting effect.(2)The weak cold air dispersed to the south and southwest to trigger storms with multiple cells consecutive⁃ly,which traveled in the northwest⁃southeast direction as they were steered by the upper⁃level northwesterly.Cells at the top of the route matured the earliest and newly formed cells kept evolving as they were driven by a cool pool resulting from old cells,causing highly organized backward transport and echoes in the form of train effect led to the localized and unusually heavy rain.(3)The process studied is a multi⁃cell storm with a low⁃level mass core and high precipitating efficiency.Its mesoscale radial convergence is conducive to the maintenance or growth of cell intensity.(4)For the same reflectivity value,the larger the K_(DP),the more in⁃tense the precipitation,which can be of reference value for determining rain intensity.
作者
冼星河
李婵珠
张玮
XIAN Xing-he;LI Chan-zhu;ZHANG Wei(Meteorological Bureau of Dongguan,Dongguan 523000)
出处
《广东气象》
2022年第4期16-19,共4页
Guangdong Meteorology
基金
东莞市气象局科研项目“新型观测资料在东莞大暴雨过程中的对比应用”。
关键词
天气学
特大暴雨
雷达
多单体风暴
后向传播
广东
synoptics
unusually hard rain
radar
multi⁃cell storm
backward transport
Guangdong
