甘肃中部一次强对流天气的多普勒雷达特征分析

利用兰州CINRAD/CC多普勒天气雷达观测资料及探空资料、自动站及测站150 km范围内的数字高程模型(DEM)资料等,对2004年8月18日发生在甘肃中部的中小尺度冰雹天气过程进行分析。结果表明:这次强对流天气过程主要在高空冷干低层暖湿及地形影响下触发的,属典型的不同平流型降雹过程[1];在多普勒雷达反射率因子图上出现典型的“人”字型、“弓”型回波;在平均径向速度图上出现逆风区、中气旋;在冰雹形成区有低层辐合、高层辐散等特征;在不同仰角的PPI上气流表现出强烈的旋转和上升;强回波区与辐合区、逆风区、中气旋、VIL在位置上有很好的对应关系,同时VIL产品对冰雹落区预报有很好的指示作用。

Analysis of Echo Character of Doppler Radar for a Severe Convection in the Mid-Part of Gansu Province

Combining CINRAD/CC Doppler radar data with some routine observation data including surface and aerological chart,Yuzhong RW station information,ground-based automatism stations observations and DEM data in the distance of 150 km,the mesoscale weather processes on 18 August 2004 have been analyzed.The results show that the severe convective processes happened under upper level cold and lower level warm advection circumstance and terrain effect belonging to different advection type hailstorm.The herringbone and bow echo shape of reflectivity factor have occurred,adverse wing region and microcyclone appear of average radial velocity,and there are convergence on lower level and divergence on upper level characters in the regions of hail formed.There are strongly circumgyrating and rising air current in the PPI.The strong echo region may be some relationships with convergence region,adverse wind region,microcyclone,VIL region,at the same time,VIL product is well used for region prediction of hail happened.