长沙地区一次暖区暴雨特征及成因分析

The Characteristics and Causes of a Warm-Sector Torrential Rainfall in Changsha

摘要: 2019年5月12~13日，长沙地区发生了连续暴雨天气，利用常规观测资料、FY-2G卫星TBB资料，自动站降水量以及NCEP/NCAR再分析资料，着重分析此次暖区暴雨的特征及成因，得出以下结论：1) 此次暖区暴雨为低层暖平流强迫型，对流条件弱，水汽条件好，持续时间长，降水落区上游有明显的水汽通量大值区。2) 此次过程低空急流较弱，长沙位于高空急流南侧300 km左右，为暴雨提供了良好的条件。3) 此次暴雨以层积云降水为主，主要降水落区与TBB大值区配合较好。

Abstract: The characteristics and causes of warm-sector rainfall in Changsha during 12-13 May, 2019 are analyzed using the data of conventional observation, FY-2G, automatic weather station precipitation, and NCEP/NCAR reanalysis product. Results are as follows: 1) The warm-sector torrential rainfall is the type of low layer warm advection forcing with weak convection conditions, sufficient water vapor and lasts a long time while there is obvious high water vapor flux in the falling area. 2) The low-level jet is weak in this process, and Changsha is located about 300 km south of the high-level jet, which provides good conditions for torrential rainfall. 3) The rainfall is dominated by cumulus precipitation, and its falling area is located in the TBB large area.