2015年春季湖南两次混合对流天气过程对比分析  

Contrastive Analysis of Two Mixed Convective Weather Processes in Hu'nan in Spring of 2015

作　　者：唐佳 姚蓉 王晓雷 唐明晖 周长青 

机构地区：[1]湖南省气象台,湖南长沙410118

出　　处：《干旱气象》2017年第2期250-259,共10页Journal of Arid Meteorology

基　　金：湖南省气象局重点课题(XQKJ15A002);中国气象局预报员专项(CMAYBY2016-048);中国气象局预报预测核心业务发展专项(CMAHX20160210);公益性行业(气象)科研专项(GYHY201306016)共同资助

摘　　要：利用高空、地面观测资料及NCEP再分析资料和多普勒雷达资料,对2015年春季湖南2次混合对流天气的环流配置、环境条件、雷达回波等特征进行对比分析。结果表明:4月3日强对流过程("4·3"过程)属于暖平流强迫类,4月19日强对流过程("4·19"过程)属于斜压锋生类。"上干下湿"的温湿层结、较大的对流有效位能、明显的下沉有效位能、中等以上热力不稳定层结及强的深层垂直风切变为2次混合对流发生发展提供有利的热、动力不稳定条件。不同之处,"4·19"过程的热力不稳定条件比"4·3"过程强,但动力不稳定条件比"4·3"过程弱。雷达产品显示,"4·3"过程的冰雹主要由超级单体风暴所致,雷暴大风由线状对流风暴引起,积层混合性降水回波所产生的"列车效应"导致湘东北极端暴雨发生;"4·19"过程受超级单体风暴影响产生冰雹、雷暴大风。Based on the aerological sounding and surface observation data,NCEP reanalysis data and Doppler radar data,the circulation configurations,environmental conditions and radar echoes of two mixed convective weather processes occurring in Hu＇nan Province on 3 April and 19 April 2015 were analyzed contrastively. The results show that the synoptic type of the severe convective process on 3April 2015 belonged to warm advection forced category,while that of the severe convective process on 19 April 2015 belonged to baroclinic frontogenesis category. The unstable stratifications with warm and wet in lower level and dry and cold in upper level,larger convective available potential energy,obvious sinking available potential energy,moderate above thermal instability and strong vertical wind shear in deep level were beneficial to the occurrence and development of two mixed convection. However,the thermal and dynamical conditions of two convective processes were obviously different,the thermal instability of＂4·19＂process was stronger than that of＂4·3＂process,while the dynamical instability of＂4·19＂process was weaker than that of＂4·3＂process. Radar products showed that the hails of ＂4·3＂process was mainly caused by the supercell storms,the thunderstorm gale was induced by linear convection storm,and the mixed rainfall echo of cumulus and stratus produced＂train effect＂,which led to the extreme heavy rain in the northeast of Hu＇nan. The hails and thunderstorm gale of ＂4·19＂process were caused by the supercell storm.

关 键 词：混合对流 环流配置 热力不稳定 垂直风切变 

分 类 号：P458.121[天文地球—大气科学及气象学]