1907号南海台风“韦帕”造成防城港大暴雨诊断分析  

Diagnostic Analysis of a Heavy Rainstorm Initiated by"WIPHA"Typhoon Over South China Sea in Fangchenggang

作　　者：陈绍河 赵胜男 骆艺仁 CHEN Shaohe;ZHAO Shengnan;LUO Yiren(Guangxi Fangchenggang Meteorological Bureau,Fangchenggang 538001,China)

机构地区：[1]广西壮族自治区防城港市气象局,广西防城港538001

出　　处：《中低纬山地气象》2021年第4期8-14,共7页Mid-low Latitude Mountain Meteorology

基　　金：广西气象局台风与海洋预报服务创新团队资助。

摘　　要：利用1°×1°NCEP再分析资料、卫星云图和雷达资料等,采用天气学诊断方法,分析1907号南海台风“韦帕”造成防城港大范围大暴雨的原因。结果表明:①“韦帕”引导气流弱、移动速度缓慢、强度减弱慢、中心登陆防城港是造成防城港大暴雨的主要原因;②“韦帕”对流云系长时间滞留防城港上空,是造成防城港大暴雨的直接原因;③台风过程降水为对流性降水,台风降水效率高导致防城港出现大范围大暴雨;④防城港上空一直位于925 hPa水汽辐合中心和850 hPa垂直上升运动中心或附近,有利于大量水汽集结抬升形成对流云系产生持续性强降水;⑤“韦帕”影响防城港期间大气对流非常不稳定,湿正压项(MPV1)分布对较强降水落区有指导意义,强降水主要出现在湿正压项负值中心附近;⑥“韦帕”环流后部在防城港上空有一条偏东南风急流带,这条急流带在十万大山山脉前被迫抬升形成对流,对防城港出现大暴雨有明显增幅作用。Based on 1°×1°NCEP 6 hour reanalysis data,satellite cloud data and Doppler Radar Data,used synoptic diagnosis method,the reasons of a heavy rainstorm which caused by typhoon"WIPHA"over southchina sea in Fangchenggang were diagnosed.The conclusions are as follows:①The weak steering flow of typhoon,the slow typhoon center moving speed,the intensity of typhoon weakened slowly and typhoon center made landfall in Fangchenggang what was the primary cause of a heavy rainstorm;②Typhoon center clouds stranded over Fangchenggang a long time,what was the direct cause of a heavy rain;③Typhoon precipitation was convective precipitation and the precipitation efficiency was high,what caused large area heavy rain in Fangchenggang;④Fangchenggang was always located at the 925 hPa water vapor convergence center and 850 hPa vertical upward movement center or near,which was conducived to the accumulation and uplift of a large amount of water vapor to form convective cloud system and produce persistent heavy precipitation;⑤The atmospheric convection was very unstable during the period of"WIPHA"in Fangchenggang and heavy rainfall mainly occured near the negative center of wet positive pressure(MPV1),which had guiding significance for the heavy rainfall area;⑥There was a wide southeast wind jet belt behind the"Weipa"Circulation over Fangchenggang,which was forced to rise in front of Shiwan mountains to form convection and had an obvious effect on the occurrence of heavy rain in Fangchenggang.

关 键 词：南海台风 台风“韦帕” 大暴雨 物理量场 地形作用 

分 类 号：P458.121.1[天文地球—大气科学及气象学]