云南一次强对流冰雹过程的环流及雷达回波特征分析

Circulation Background for a Severe Convective Hailstorm Weather Process in Yunnan and Its Dopplar Radar Echo Features

详细分析了云南2001年7月6日强对流冰雹天气过程的多普勒雷达加密观测回波资料和各种物理量场。结果表明,高层辐散流场和低层辐合流场的配置形成大气强烈不稳定,在有利的大尺度背景条件下产生的三个中-β系统直接导致此次滇中强对流冰雹天气过程,在多普勒雷达回波上具有典型的右后侧V型槽口回波、弱回波区(WER)、弓形回波、阵风锋回波、钩状回波、回波墙穹隆(弱回波区)和悬挂回波等特征,并且强回波区与多普勒雷达速度场上的逆风区、大风区和风辐合区相关。

The intensive observation echo data of the Doppler radar and the physical quatities of the severe convective hailstorm weather on 6 July 2001 are analyzed, the results show that the combinations of upper air divergence and lower air convergence form the strong atmospheric instability, the three meso-βscale convective systems producted under the advantageous large scale background directly cause severe convective hailstorm process in middle part of Yunman. There are many features of Dopplar Radar echoes, such as rear-flank notch, weak echo region （WER）, bow echo, gust front echo, hook echo, echo wall, vault, echo overhang etc, and the strong echo areas are related to the areas of the anti-wind, the large radial velocity and wind convergence in Dopplar radar velocity field.