一次强对流风暴的新一代天气雷达特征分析

Analysis of New Generation Weather Radar Data for a Severe Convective Storm

利用兰州皋兰山的CINRAD/CC多普勒天气雷达资料,对2005年5月30日15～19时发生在甘肃中部地区的一次强对流风暴进行了分析。引起此次强对流风暴的中尺度天气系统是飑线,飑线尾部位于甘肃中部的强雷暴区在15时生成,沿东南方向移动,在16时15分至17时03分多单体风暴加强合并为超级单体风暴,并呈现出人字型回波、带状回波特征。此次超级单体南边出现2条明显的出流边界,一条位于钩状回波的西南,一条位于钩状回波的东南。超级单体左前方的低层反射率因子呈现明显的倒“V”字型结构,最大的回波强度出现在有界弱回波区之上,其值>70 dBZ,相应径向速度图呈现出成熟的中气旋特征,期间垂直液态水含量持续偏高,最大垂直累积液态水含量>70 kg/m2,回波顶高达17～18 km,该风暴具有强烈超级单体风暴的典型特征。

A severe convective storm process occured in the middle of Gansu province on May 30, 2005 was analyzed by using CINRAD/CC Doppler weather radar data. It is found that the main meso - scale system causing this severe convective storm was the squall line. The storm first appeared at 15：00, then moved to the southeast, and from 16：15 to 17：03 the multi -cell storm became more strongly and developed into the super - cell storm with the characteristics of vortex and zonal echoes. There were two obvious outflow boundaries observed in south of the supercell lying to the southwest and southeast of the hook echo of the storm, respectively. The shape of the low elevation reflectivity in the left front flank of the supercell was an inverted ＂V＂, the maximum of echo intensity appeared in the bounded weak echo zone with the value over 70 dBZ. The corresponding radial velocity maps showed a strong mature meso - cyclone feature. In this period the maximum vertical integrated liquid water （VIL） reached above 70 kg/m^2 and the height of echo top （ET） was 17 - 18 km. Hence, this storm presented the typical features of superceU storms.