阿瓦提县初夏一次强冰雹天气成因分析

Analysis of the Cause of a Strong Hail Weather in Early Summer in Awati County

利用MICAPS常规观测资料,对2017年6月7日阿克苏地区阿瓦提县的强冰雹天气过程成因进行分析。结果表明:此次强冰雹天气是巴尔喀什湖附近的低涡底部分裂的短波槽东移影响阿克苏地区所致;降雹前,巴尔喀什湖南部低槽大气斜压不稳定,迫使阿瓦提县上空中低层大气在正涡度平流的作用下促使气块产生气旋转式辐合抬升,气旋式辐合抬升的持续发展与加强,有利于将中低层暖湿空气整体抬升;低层暖湿、高层干冷的不稳定层结为此次冰雹提供了有利的环流条件,高低空天气系统合理配置、局地气象条件和中小尺度系统相互作用和不稳定能量的发展都有利于冰雹产生。

Used the routine observation data of MICAPS, the causes of the severe hail weather process in Awati County, Aksu region on June 7, 2017 were analyzed. The results showed that the strong hail weather was caused by the eastward movement of the short wave trough split at the bottom of the vortex near Balkhash Lake, which affected Aksu area. The baroclinic instability of the low trough atmosphere in the south of Balkhash before hail forced the lower atmosphere in the upper air of Awati county to produce cyclonic convergence and uplift under the action of positive vorticity advection. The continuous development and strengthening of cyclonic convergence and uplift is conducive to the overall uplift of the warm and humid air in the middle and lower layers. The unstable stratification of warm and wet low-level and dry and cold high-level provided favorable circulation conditions for the hail. The reasonable configuration of high and lowlevel weather system, local meteorological conditions, the interaction of small and medium-sized systems, and the development of unstable energy were conducive to the generation of hail.