北上台风引发锦州连续性暴雨的成因分析

Analysis on the Cause of Continuous Rainstorm Caused by Northbound Typhoon in Jinzhou

【目的】诊断分析锦州地区2019年8月10日至15日出现的连续性暴雨。【方法】利用Micaps实况数据资料、ECWMF再分析资料等进行分析。【结果】受西风带冷空气、副热带高压及减弱台风“利奇马”外围云系等连续影响,锦州地区此次暴雨过程持续时间长、累计雨量大、风力较强、致灾程度高,总降水量达暴雨到大暴雨量级,局部特大暴雨。【结论】此次暴雨持续时间长、累计雨量大主要是由于副热带高压和大陆高压两高对峙,移速较慢,以及源源不断的水汽和能量补充的影响,高层辐散、低层辐合的高低空配置有利于垂直上升运动发展。此外,冷空气从底层卷入使台风“利奇马”结构破坏,减弱填塞,斜压发展,虽然缩短了台风生命史,却是造成本次暴雨“长时效”特点的关键。

[Purposes]In this paper,the continuous rainstorm occurred in Jinzhou area from 10 to 15 Au⁃gust 2019 was diagnosed and analyzed.[Methods]Micaps live data and ECWMF reanalysis data were used for analysis.[Findings]Under the continuous influence of the cold air in the westerlies,the sub⁃tropical high pressure and the outer cloud system of the weakened Super Typhoon Lekima,the rainstorm in Jinzhou area lasted for a long time,the accumulated rainfall was large,the wind was strong,and the de⁃gree of disaster was high.The total precipitation reached the level of rainstorm to heavy rainstorm and lo⁃cal heavy rainstorm.[Conclusions]The long duration and large cumulative rainfall of this rainstorm are mainly due to the confrontation between the subtropical high and the continental high,the slow move⁃ment speed,and the continuous supply of water vapor and energy.The high and low altitude configura⁃tion of high-level divergence and low-level convergence is conducive to the development of vertical as⁃cending motion.In addition,the involvement of cold air from the bottom destroyed the structure of ty⁃phoon“Lekima”,weakened the packing,and developed baroclinicity.Although the life history of ty⁃phoon was shortened,it was the key to the“long aging”of this rainstorm.