摘要
利用常规观测资料、卫星云图资料、雷达回波和NCEP全球最终分析资料(FNL),对2010年7月19日新乡区域性大暴雨过程进行了诊断分析。结果表明:在西南涡与副高相互作用的天气形势下,中低层切变线等影响系统造成了这次区域性大暴雨;对流层中低层副高外围强盛的西南急流将海上充沛的水汽输送到大暴雨区并在此汇集,造成新乡地区上空强降水期间稳定维持深厚的湿层;中低层在新乡地区有强盛的西南急流与偏东气流的辐合,高层有较强的西南气流辐散,有利于上升运动的发展和维持;整个强降水时段,新乡地区上空对流云团tbb值在-50～-44℃之间,对流发展不旺盛,新乡地区以稳定的持续性强降水为主,没有发生雷暴等强对流天气。
By using routine observational data,satellite cloud image,radar echo and the FNL data of NCEP,the rainstorm event over Xinxiang on 19 July 2010 is analyzed.The result shows that the heavy rainstorm is affected directly by the Western Pacific Subtropical High（WPSH） when it interacts with southwest vortex in addition to the shear line of middle and lower layer.During the heavy rainstorm period in the middle and low troposphere,abundant water vapor over ocean is transferred towards continent by the lasting strong southwest jet southwesterlies along the southwest of the WPSH.The water vapor fluxes are converged over Xinxiang and result in the constant deep saturation vapor there during the heavy rainfall period.Over Xinxiang the middle-low-level convergence causing by the southwest jet and the easterly matches with the upper-level divergence causing by strong southwesterly airflow,which results in the ascending motion to further maintain and improve.During the rainstorm the value of tbb ranges between-50 ℃ and-44 ℃,the development of convection isn＇t strong.The features of rainstorm are steady and consistent strong rainfall without convective weather phenomena such as thunder and lighting over Xinxiang.
出处
《气象与环境科学》
2011年第1期49-55,共7页
Meteorological and Environmental Sciences
基金
河南省气象局气象科学技术研究项目(Z200704)资助
关键词
大暴雨
副高
西南涡
heavy rainstorm
subtropical high
southwest vortex
