豫中南一次秋季区域性暴雨成因分析  

Cause Analysis of the Autumn Regional Rainstorm in South-central Henan

作　　者：武威 顾佳佳 牛淑贞 胡燕平 Wu Wei;Gu Jiajia;Niu Shuzhen;Hu Yanping(Luohe Meteorological Office,Luohe 462300,China;Henan Provincial Meteorological Observatory,Zhengzhou 450003,China)

机构地区：[1]漯河市气象局,河南漯河462300 [2]河南省气象台,郑州450003

出　　处：《气象与环境科学》2018年第1期94-102,共9页Meteorological and Environmental Sciences

基　　金：河南省科技攻关项目(162102310056);中国气象局2017年气象预报业务关键技术发展专项(YBGJXM(2017)02-08);河南省气象局预报员专项(KQ201741)资助

摘　　要：利用常规观测资料、加密自动站资料、NCEP 1°×1°分析资料、FY-2E卫星及雷达资料等,采用诊断分析和对比分析方法,分析了2014年9月27—28日豫中南区域性暴雨的环流形势、强降水成因、中尺度特征及该过程与夏季暴雨的异同。结果表明:本次秋季暴雨过程是高空低槽、副高、中低层切变线、高低空急流、地面倒槽等系统共同作用的结果。持续的水汽辐合为暴雨提供了充沛的水汽条件,水汽通量大值区与水汽辐合中心分布及暴雨落区吻合;低层涡度的发展和水平风的切变导致垂直涡度发展,动力条件较好;K指数高值区对预报暴雨尤其强降水落区有较好指示意义,暴雨中心上空θse值随高度递减,高层低能舌叠加在低层高能区之上,强降水落区位于二者交汇的区域。低层偏东气流与高空槽前西南气流配合产生经向次级环流,上升运动增强;200 h Pa西风急流稳定维持,导致高层抽吸作用明显,有利于区域性暴雨发展。降水云团tbb一般在-32℃左右,发展高度明显低于夏季暴雨云团;降水前期回波为层云回波,后期转变为混合性回波,强降水主要由混合降水回波中的强对流云团导致的。中高层没有明显强冷空气,低层冷空气作用较大,东路冷空气一方面形成冷垫造成动力抬升,另一方面在低层与暖湿气流形成强水汽辐合,是本次秋季区域性暴雨的形成机制,也是不同于夏季暴雨的主要特征。Based on the conventional observation data,intensive automatic station data,NCEP 1° ×1° analyzed data,the FY-2 E satellite data and radar data,the regional rainstorm in south-central Henan from the 27 th to 28 th in September 2014 was researched by diagnostic analysis and comparative analysis,the circulation situation,the causes of rainstorm as well as mesoscale features and the similarities and differences from summer storm was summarized. The results showed that： the autumn rainstorm is under the combined effect of trough in high-level,subtropical high,the shear line in middle and lower-level,the high and low jets and ground inverted trough. Sustained water vapor convergence provides abundant moisture for rainstorm and the large value of water vapor flux and water vapor convergence center matched rainstorm area. The development of low level vorticity and the horizontal wind shear lead to the development of vertical vorticity,which makes better dynamic conditions. The high value distribution of K index had better implications for forecasting heavy rain especially the strong precipitation area. The θsedecreased with altitude. Low energy tongue in high level superimposed over high energy region in low level,and the strong precipitation area locates in two superposed regions. Low-level easterly winds and upperlevel trough produce the secondary circulation,and forms a strong upward motion. The westerly jet in 200 h Pa stably maintained,leading to obvious aspiration in the high-level,which was conducive to the development of regional rainstorm. The tbbwere mostly maintained at-32 ℃ during the process,the height of rain clouds developed was significantly lower than the storm clouds in summer. The precipitation echo is stratiform cloud in the early stage and mixed echo by the late and the convective clouds of mixed precipitation echoes leads to heavy precipitation in south-central Henan. There was no significant cold air in the middle and high-lever,and cold air in the low-level made great contributions. The ea

关 键 词：区域性暴雨 水汽辐合 垂直涡度 次级环流 异同分析 低层东路冷空气 

分 类 号：P458.121.1[天文地球—大气科学及气象学]