豫东地区一次强飑线天气过程的综合分析

Synthetic Analysis of a Strong Squall Line in Eastern Henan

利用NCEP 1°×1°逐6 h再分析资料和常规观测资料、地面加密自动站观测资料以及卫星云图和多普勒雷达资料,对2009年6月3日河南东部地区一次强飑线天气过程的环流形势、影响系统与形成条件进行综合分析。结果表明:在东北冷涡维持的有利环流形势下,冷涡后部横槽引导冷空气南下,以及地面中尺度辐合线为豫东飑线发生提供了触发机制,飑线沿辐合线发展加强,强对流天气发生在卫星云图亮温梯度最大区;飑线过程对应雷达回波图上强对流单体初生、发展、合并与减弱,相对风暴径向速度图上辐合线后部始终对应大风、冰雹等强对流天气发生区,对强对流天气预警具有较好的指示意义。

A synthetic analysis on the circulation patterns,influence systems and formation mechanisms of a strong squall occurred in eastern part of Henan province on 3 June 2009 was made with the 6-hourly NCEP 1°×1°reanalysis data,conventional observation data,intensive automatic weather station observation data,satellite images and Doppler-radar data.The results indicate that the Northeast China cold vortex continuing,the zonal trough behind the cold vortex leading cold air to a southward move and the surface mesoscale convergence line supplied a trigger effect for the occurrence of strong squall.The squall developed and reinforced along convergence line,and severe convective weather emerged in the great value center of brightness temperature gradient of satellite images.The changes of the squall line process corresponded to the genesis,developing,merging and weakening of severe convection cells which could be found in the radar echoes.The back of convergence line on the storm radial velocity plot was all the way corresponding with gale,hail and other strong convective weathers,which can provide better indications for severe convective weather forecast.