德兴“6.15”特大暴雨天气过程的特征分析

Feature Analysis about the "6.15" Heavy Rain in Dexing

利用高空和地面观测资料、WRF数值模式和IHR_LAPS系统资料,对2011年6月15日特大暴雨过程的环境场及物理量特征进行综合分析,结果表明:(1)低涡切变线、中高层冷温槽,以及与高空急流的合理配置,加强了暴雨区垂直环流发展,使降水区形成高空辐散、低空辐合的流场特征,促进了强降水的产生;(2)低层强而持续的水汽输送是产生强降水和大暴雨必需的水汽条件;(3)强降水区域对流有效位能大值区与暴雨中心相对应,对流有效位能的时空变化能较好地反映暴雨的时空演变特征;(4)地面温度密集区的存在,温度梯度锋稳定少动,有利于地面中尺度辐合的形成、发展和维持,有利于强降雨的发生;(5)暴雨产生在中低层螺旋度中心和不稳定能量高能区中,局地螺旋度大值中心的高低层耦合叠加且持续,对暴雨的落区及预报有指示意义。

Using the sounding data,surface meteorological observations,WRF numerical model and IHR_LAPS data,potential conditions of environmental field and physical characteristics were analyzed during the heavy rain on June 15,2011.The results showed that：（1）Vortex shear line,the high-level cold temperature slots,and compositional with jet stream,developed the vertical circulation of the heavy rain area,produced the characteristics with upper level divergence and low level convergence,make precipitation strengthening.（2）Plentiful vapor leaded to the strong precipitation and heavy rain.（3）The high value of CAPE corresponding with the rainstorm center,the space-time evolvement of CAPE showed the space-time evolvement characteristics of the heavy rain.（4）The ground stable temperature front was useful for the development of the mesoscale convergence,as well as the heavy rain occurred.（5）Both the low-rise spiral degrees center and high value of CAPE were the areas where the heavy rain occurs.The high value of local spiral degrees compositional with numerous lays,it was significant for the heavy rain forecast.