2022年6月上饶市极端暴雨天气过程成因分析

Cause Analysis of Extreme Rainstorm Weather Process in Shangrao in June 2022

基于常规气象观测资料、ERA50.25°×0.25°再分析数据和雷达观测资料对2022年6月上饶市的一次极端暴雨过程进行天气学动力诊断和成因分析,结果表明:(1)此次持续性暴雨过程是南海季风暴发、西风带系统东移、东北冷涡后部偏弱的冷空气南下、副热带高压稳定维持共同作用的结果。(2)江西东北部的对流层高层处于高空急流的入口区和低层辐合区叠加,上下抽吸作用加强了暖湿气流的垂直上升运动。(3)冷暖气团长时间在赣东北对峙,是暴雨长时间在赣东北维持的原因,远高于大气可降水量的气候态(近5年),为极端强降水提供了异常强盛的水汽条件。

Based on the conventional meteorological observation data,ERA50.25°×0.25°reanalysis data and radar observation data,the synoptic dynamic diagnosis and cause analysis of an extreme rainstorm process in Shangrao City in June 2022 are carried out.The results show that:(1)the persistent rainstorm process was the result of the combined action of the South China Sea monsoon outbreak,the westerly belt system moving eastward,the weak cold air moving southward behind the northeast cold vortex,and the stability of the subtropical high.(2)The upper level of the troposphere in northeastern Jiangxi was located in the entrance area of high-altitude jet streams and the convergence area of lower levels.The upward and downward suction enhances the vertical upward movement of warm and humid airflow.(3)The long-term confrontation between the cold and warm air mass in the northeast of Jiangxi was the reason why the rainstorm has been maintained in the northeast of Jiangxi for a long time,which was far higher than the climate state of atmospheric precipitable water(nearly 5 years),providing exceptionally strong water vapor conditions for extreme heavy rainfall.