一次冷涡横槽型强对流天气过程分析  

Analysis of a Server Convection Weather Process in the Situation of Cold Vortex and Zonal Trough

作　　者：牛淑贞[1,2] 张宇星[3] 吕林宜 

机构地区：[1]中国气象局.河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气象台,郑州450003 [3]河南省气象局,郑州450003

出　　处：《气象与环境科学》2013年第2期1-9,共9页Meteorological and Environmental Sciences

基　　金：河南省科研计划重点项目(112102310033);中国气象局关键技术集成项目(CMAGJ2012M31)资助

摘　　要：利用加密探测资料和新一代天气雷达产品资料,对2012年7月12日夜到13日凌晨发生在河南省东北部的一次局地强对流天气过程进行分析可知:此次过程为典型的东北低涡后部横槽转竖携带冷空气下摆造成,发生在弱垂直风切变和大CAPE的环境条件下,具有干对流特征,850 500 hPa的温差在25～30℃之间,高空冷槽叠加低层暖脊,使得CAPE从当日08时的≤1000 J/kg增大到20时的1000～3500 J/kg;郑州0 6 km和0 2 km的垂直风切变分别是6.06 m/s和2.89 m/s,属弱垂直风切变。地面中分析表明,强对流天气发生在地面高温高湿及等温、等露点线密集区和辐合相叠加区。雷达资料分析表明:此次强对流回波自山东南部生成并向西传播影响开封地区,随后与西北和北部东南移的对流回波在新乡地区东部汇合加强,然后西移影响郑州地区;径向速度图上具有明显的辐散系统和大风区,在大风发生时段有中气旋产品出现,中气旋直径为4.50～5.00 km,大风发生前后中气旋的切变值由10×10-3s-1增大到16×10-3s-1,最大值52×10-3s-1出现在00:37,即延津大风发生时和兰考大风发生前19～44 min,为强对流天气的临近预报预警提供了参考依据。SWAN产品虽有偏差,但具有一定参考价值。The intensive observations and new generation weather radar products were used to analyze a local server convection weather which occurred in northeastern part of Henan province between the night of 12 July 2012 to the early morning of July 13.The results showed that： this process was happened by the transversal trough changed to be vertical behind the typical northeast vortex leading cold air to downwards,occurred at the environmental conditions of weak vertical wind shear and big convective available potential energy（CAPE）,and with dry convection characterize,the 850 hPa to 500 hPa vertical temperature lapse rate between 25 ℃ to 30 ℃,the configuration of upper cold trough and lower warm ridge made the CAPE increased to 1000-3500 J/kg at 20：00,from less than 1000 J/kg at 08：00 on the day,the vertical wind shear of 0-6 km and 0-2 km were 6.06 m/s and 2.89 m/s,belonged to the weak vertical wind shear.Surface mesoanalysis showed that server convection weather occurred on the area of high temperature and humidity,isothermal and isodrosotherm concentrated region which superposed with convergence line on the surface.The radar data analysis showed that the server convective echoes occurred at southern part of Shandong province and propagated westward to affect Kaifeng area,followed by confluence and enhanced at eastern part of Xinxiang with the convective echo from northwest and north shifted southeastwards,then expanded westwards and influenced Zhengzhou region.The obvious divergence system and windy area were showed on the radial velocity plot,the mesocyclone products were appeared in the period of high wind,the diameter of the mesocyclone was 4.50-5.00 km,the wind shear of mesocyclone before and after wind occurred were increased by 10×10-3 s-1 to 16×10-3 s-1,the maximum value was 52×10-3 s-1 which appeared at 00：37 when the high wind occurred in Yanjin and the 19-44 minutes before high wind occurred in Lankao,it provided the reference for the server convective weather nowcasting and warming.Altho

关 键 词：温度垂直递减率 对流传播 辐散流场 临近预警 

分 类 号：P458.3[天文地球—大气科学及气象学]