河北廊坊一次局地强对流天气过程分析

Analysis of a Local Severe Convection Weather in Langfang, Hebei

摘要: 利用常规观测、加密自动站及雷达观测资料，分析2017年廊坊北部一次局地短时强降水和短时大风强对流天气过程成因。结果表明：本次天气过程是发生在高空槽后部西北气流形势下，水汽条件和动力条件均有利于强对流天气的发生和发展，但强对流出现的具体地点和时间仍为预报难点。强对流天气发生前地面辐合线触发新对流向东南传播并加强，强回波和较大VIL值预示短时强降水的出现，径向速度大值区预示着短时大风的出现，雷达STI产品较好预报了强回波移动方向，预警提前量约为30 mins左右。

Abstract: A local short-time heavy rainfall and strong wind convection weather in northern Langfang in 2017 were analyzed in this paper by using conventional observation data, ground encryption automatic station data and radar data respectively. The results showed that: this weather process occurred under the condition of northwest airflow at the rear of the high-altitude trough. The conditions of water vapor and dynamics are conducive to the occurrence and development of strong convection weather, but the exact location and time of the occurrence of strong convection are still difficult to predict. Before the occurrence of strong convection weather, the ground convergence line triggered the new convection to propagate to the southeast and strengthened. Strong echoes and large VIL values foreshadow the occurrence of short-term heavy precipitation. The region of large radial velocity indicates the occurrence of short-term strong winds. STI better predicts the direction of strong echo movement, and the early warning amount is about 30 mins.