2014-2020年梧州市短时大暴雨雷达回波特征分析

Analysis of radar echo characteristics of short-term rainstorm in Wuzhou City from 2014 to 2020

利用梧州市多普勒天气雷达和自动气象站降水资料,分析2014-2020年发生在梧州市的短时大暴雨天气过程的雷达回波特征。结果表明:(1)大暴雨与45dBz以上的强回波和持续时间密切相关,发生短时大暴雨时,最大反射率因子超过50dBz,45dBz以上的强回波持续时间基本在50min以上;(2)质心高度在2km以下,且维持时间10min以上的低质心强回波容易形成暴雨;(3)强回波和辐合区相结合易形成大暴雨,与逆风区辐合区关系最密切,占6成多;(4)强回波带和列车效应相结合易形成大暴雨:回波带上单体或回波团的移动方向和回波带走向一致易形成大暴雨;(5)回波顶高和垂直累积液态含水量产品出现大值的时间对大暴雨预报预警有指示意义。

Based on the Doppler weather radar and precipitation data of automatic weather station in Wuzhou City, the radar echo characteristics of short-term rainstorm weather processes in Wuzhou City from 2014to 2020 were analyzed. The results show that(1) the rainstorm is closely related to the strong echo and duration above 45d Bz. When the short-term rainstorm occurred, the maximum reflectivity factor exceeded 50d Bz, and the strong echo duration above 45d Bz was basically over 50 min.(2) The low centroid strong echo with centroid height less than 2km and maintenance time more than 10 min is easy to form rainstorm.(3) The combination of strong echo and convergence area is easy to form rainstorm, which is most closely related to the convergence area of upwind area, accounting for more than 60%.(4) The combination of strong echo band and train effect is easy to form rainstorms: the moving direction of monomer or echo group on the echo band is consistent with the direction of the echo band, which is easy to form rainstorms.(5) The echo top height and the time when the vertically accumulated liquid water content product has a large value are instructive to the prediction and early warning of rainstorms.