2018年香日德一次典型大雨天气成因分析

Cause Analysis of a Typical Heavy Rain in Xiangri De in 2018

利用高空、地面、物理量场、卫星云图、地面自动站等资料对2018年香日德典型大雨过程成因进行分析。得出预报此次单点大雨着眼点:东移入境的藏北低涡切变线为此次过程主要影响系统;地面上来自新疆的冷锋未形成锢囚锋、槽的移动和冷锋后期无强冷空气支持给具体大雨落区带来较大不确定性,但冷空气在爬坡消耗时维持在雨区;涡度、散度、垂直速度叠置区及地面至中高层湿区与水汽通量散度汇合区域对大雨落区有较好指示;气团在山脉迎风坡前堆积抬升对较大降水有利,单点降水需更多着眼于地形和中小尺度分析。

Analyzes the causes of the typical heavy rain process in Xiangri de in 2018 by using the data of high altitude,ground,physical field,satellite cloud image,ground automatic station,etc.,and obtains the forecast focus of the single point heavy rain:the shear line of the northern Tibetan vortex moving eastward is the main influence system of the process;the cold front from Xinjiang on the ground does not form a trapped front,and there is no strong cold air in the movement of trough and the later stage of cold front The results show that the air support brings great uncertainty to the specific heavy rain area,but the cold air maintains in the rain area when climbing the slope;the overlapping area of vorticity,divergence,vertical velocity and the convergence area of surface to middle and high-level wet area and water vapor flux divergence have good indication for the heavy rain area;the accumulation and uplift of air mass in front of the windward slope of the mountain is beneficial to the larger precipitation,and the single point precipitation needs to pay more attention to the terrain influence and Small and medium scale analysis.