固原“8.25”冰雹天气过程诊断分析

目的]研究固原市一次冰雹天气过程。方法]综合利用常规观测数据、数值预报产品和和天气雷达资料等,分析了固原市2011年8月25日一次强对流冰雹天气过程。结果]高空冷块、低层暖温气流和低空切变线是这次天气的主要影响系统。低层辐合、高层辐散、旺盛的上升运动以及低空暖气流和水汽供给为冰雹天气的发生发展提供了极为有利的动力条件。冰雹指数(HI)是预报(固原)冰雹天气的有效的雷达指标。反射率因子和VIL与冰雹天气关系较密切。结论]该研究为今后强对流天气的短时、临近预报工作积累了经验。

Diagnostic Analysis of Hail Weather in Guyuan on August 25, 2011

Objective] To study a strong convective hail weather process in Guyuan.Method] By comprehensively using conventional observation data,numerical forecast products and Doppler weather radar data,a strong convective hail weather process which happened in Guyuan on Aug 25,2011 was analyzed.Result] The strong convective weather was mainly affected by the high-altitude cold air,lower warm-wet airflow and shear line.The low-level convergence and high-level divergence,strong rising,lower warm-wet airflow and water vapor supplies offered favorable dynamical conditions for the hail occurring and developing.HI(Hail Index) is an effective radar forecast index of Hail in Guyuan.Reflectivity and VIL(Vertical Integrated Liquid) are significantly correlated with hail weather.Conclusion] The research accumulated the experience for the short-term forecast and nowcasting work of strong convective weather in future.