2021年秋季平凉东部罕见大暴雨成因分析
Analysis of Rare Heavy Rain in the East of Pingliang in Autumn 2021

基于常规观测资料及NCEP再分析资料，从影响系统、物理量诊断、云图及雷达回波分析2021年秋季出现在平凉东部罕见大暴雨过程形成的成因，结果发现：此次大暴雨过程是在异常偏强的西太平洋副热带高压位置偏北较强而且维持稳定，其西北侧暖湿气流强盛，不断向平凉东部暴雨区输送源源不断的水汽，低层切变线辐合系统长时间维持在平凉东部，同时叠加地面辐合线，增幅了对流降水，导致灵台极端强降水的出现。
Based on the conventional observation data and NCEP reanalysis data, the causes of the rare rainstorm process in the east of Pingliang in autumn 2021 were analyzed from the perspectives of impact system, physical quantity diagnosis, cloud map and radar echo. The results showed that: the process of this rainstorm was strong and stable in the north of the abnormally strong Western Pacific subtropical high, the strong warm and wet air in the northwest side of the rainstorm continued to transport water vapor to the east of Pingliang rainstorm area, the convergence system of the low-level shear line maintained in the east of Pingliang for a long time and the ground convergence line, which increased the convective precipitation and led to the extremely heavy precipitation in Lingtai.