“98.7”鄂东连续特大暴雨的中尺度分析(一)

MESOSCALE ANALYSIS ON THE SUCCESSIVE EXTREMELY HEAVY RAIN IN EAST HUBEI PROVINCE IN JULY 1998(I)

使用 10分钟间隔的武汉 WSR- 81S数字化雷达回波资料 ,结合逐时地面风场及雨量 ,对 1998年 7月 2 0～ 2 1日出现在湖北省东部的特大暴雨过程进行了详细的中尺度分析。结果指出 :地形对地面中 - β尺度系统的发生发展起着重要的作用 ,对流回波的发生发展则与地面中 - β尺度系统有着较好的对应关系 ,在对流层低层低涡的组织作用下 ,回波系统呈现出明显的涡旋运动 ,通过多次合并加强 ,最终造成特大暴雨。

Using ten minute WSR 81S digital radar echo data,together with hourly wind and rainfall data,the extremely heavy rain occurring in East Hubei Province in 20～21th July 1998 is analyzed.The results show that the terrain plays an important part in the occurrence and development of the surface meso scale synoptic system,and that the convective echoes correspond with the surface meso β scale system.In the organization of the vortex in the lower troposphere,the echo systems make the eddy motion and is strengthened by the many combinations so that the extremely heavy rain results from it.