三明市强对流天气的风廓线雷达探测分析

Analysis of Wind Profile Radar in the Severe Convective Weather in Sanming

利用永安风廓线雷达对近年来发生在三明的强对流天气进行特征分析。分析表明：水平风场上强对流发生前在1500~5000m一般伴有短波影响,0~500m高度伴有风向随时间旋转,说明中低层有小槽波动,近地层有小尺度气旋活动;降雹天气时,5~6km最大风速均达25m/s以上,以西南或偏西风居多,短时强降水时最大风速达15m/s;在0~1500m高度出现大风核（≥20m/s）时,一般伴随降雹天气;降雹时,6000m以下一般会出现≥20m/s的西南急流,可探至4000m以下,同时≥12m/s的急流可探至1600m以下;而强降水≥12m/s的急流可探至2000m以下。垂直速度上测站出现降水时其上空均出现≥4m/s的垂直速度区,出现强对流天气时≥4m/s的垂直速度区一般会扩展到3600m以上,强度越强扩展的高度越高;降雹和短时强降水的最大速度值差别不明显,但一般降雹时的最大正速度区（3000~5000m）高于强降水的最大正速度区（1000~3000m）。

The characteristics of the severe convective weather in Sanming were analyzed by using wind profile radar of Yongan. The results show that there was an effect of shortwave between 1500-5000 m before the severe convective broke out on horizontal wind field, and the wind direction had revolved with time under 500 m. It showed that the weak wave had been moving eastward on middle and low levels, and there was a little-scale rotation circulation on the surface layer. The maximum wind speed reached more than 25m/s during the hail fall, and the direction of wind was mostly west and southwest. The maximum wind speed reached more than 15m/s during the short-time heavy rainfall. It appeared that when the wind speed reached more than 20m/s between 0-1500 m, the hail fall often occurred. The southwest jet stream of more than 20m/s often appeared under 6000 m and even under 4000 m. Meanwhile, the jet stream of more than 12m/s often appeared under 1600 m and the jet stream of more than 12m/s often appeared under 2000 m during a heavy rainfall. The vertical velocity more than 4m/s often appeared during a rainfall, and the vertical velocity of more than 4m/s generally reached 3600 m. Additionally, if the vertical velocity was faster, the height was higher. The maximum vertical velocity of a hail fall was not obviously different from a short-time heavy rainfall. However, the area of the maximum positive velocity during a hail fall was larger than that of the short-time heavy rainfall.