20120705河南省区域性暴雨中尺度特征分析

Mesoscale analysis of a regional rainstorm in Henan province on July 5,2012

为研究区域性大暴雨的特征与机理,利用NCEP资料、常规探空资料、卫星云图、雷达及区域站观测资料对2012年7月5日河南省区域性大暴雨过程进行了诊断分析.结果表明:在低槽及副热带高压影响下,低空切变线、低空急流与地面中尺度辐合线相互作用产生了此次区域暴雨过程.冷空气的移动、对流层深厚的西南急流、中尺度辐合以及切变的形成和发展,对强降水有很好的指示作用.700 h Pa等压面上正垂直螺旋度中心的移向和强度变化与降水落区及趋势变化有很好的对应关系,对区域强降水的落区有一定的指示意义.研究结果为改进区域大暴雨预报提供了有益的信息.

Diagnostic analysis is done on a heavy storm process occurred on July 5th,2012 in Henan province, based on data of NCEP,satellite image,radar echo,sounding and ground observation from regional stations,in order to reveal the characteristics and mechanism of regional heavy storms. The results show that the low level shear line interacts with the ground shear line and the surface mesoscale convergence line to produce the heavy rainstorm,un？der the influence of trough and subtropical high. Mesoscale characteristics analysis reveals good indicators of this strong precipitation process,including the cold air movement,the deep southwest jet stream of troposphere,the for？mation and development of mesoscale convergence and shear line.The distribution and intensity of vertical helicity at 700 hPa are in agreement with the rainfall area and center.The research results provide reference for the improve？ment of regional rainstorm forecast.