甘肃省“2015·6·9”强对流天气过程诊断分析

Diagnostic Analysis of Severe Convective Weather in Gansu Province on June 9th,2015

利用基本气象资料、数值预报产品、雷达产品资料以及物理量场特征,对发生在2015年6月9日甘肃省一次强降水、冰雹等强对流天气过程进行分析。结果表明:蒙古冷涡为此次强对流天气过程的主要影响系统;高层冷平流和低层暖湿气流作用下形成对流不稳定层结,地面冷锋、低层辐合切变、中低层急流为不稳定能量释放触发机制;低层辐合、中高层为深厚辐散的配置为上升运动提供动力抬升条件;下湿上干且有明显水汽辐合的配置为强对流天气的发生提供了充沛的水汽条件;适宜的特征层高度也为冰雹的形成和降落创造了条件;分析雷达产品资料发现,河东地区影响降雹的回波单体不尽相同,垂直累积含水量的大值区与强回波中心及冰雹落点对应较好。

By using basic meteorological data,numerical forecast products,radar product data and physical quantity field characteristics,this study analyzed a strong convective weather process in Gansu Province on June 9th, 2015.The results were as follows： Mongolia cold vortex was the main influence system of the strong convective weather process;The upper cold advection and low-level warm air formed convective unstable stratification, the ground cold front,low level shear and low level jet were trigger mechanisms of the unstable energy;The low level convergence and upper level divergence provided sufficient moisture condition for strong convective weather;The suitable characteristic layer height also created the condition for the formation and the descent of hail.Further analysis of the radar products showed that the effect of hail echo form was not the same in Hedong area, the extreme value of vertically integrated liquid were better corresponded to the strong echo center and the Placement of hail.