重庆江北机场一次罕见大暴雨天气过程成因分析

Analysis of a Long-Time Torrential Rain Process at Chongqing Jiangbei Airport

摘要: 采用江北机场AWOS系统数据、机场天气实况报文和欧洲中心ERA5再分析资料等，对2025年7月8~9日一次长时间大暴雨天气过程进行分析，结果表明：1) 本次过程副高势力显著偏强且西伸北抬，与西西伯利亚平原至日本的高压系统、台风“丹娜丝”共同形成稳定的阻塞形势，导致西风槽和切变线东移受阻，长时间维持在重庆上空；2) 该次过程的水汽条件具有极端性，西南季风与副热带高压西南侧暖湿气流、台风“丹娜丝”北侧外围水汽在重庆上空汇合，为强降水的持续提供了充足的水汽供应，同时加剧了大气层结不稳定；3) 江北机场上空850~500 hPa出现明显水汽辐合中心，与上升运动区配合良好，中到大阵雨伴雷暴天气出现、持续时间与之高度吻合。

Abstract: Analysis of a long-time torrential rain process during July 8~9, 2025 by using the Chongqing Jiangbei Airport AWOS system data, Meteorological Terminal Aviation Weather Report, and the ERA5 reanalysis data reveals the following: 1) The subtropical high intensified and expanded westward and northward. Combined with a high-pressure system from the West Siberian Plain to Japan and Typhoon Danas, it formed a stable blocking pattern, resulting in the prolonged stalling of the westerly trough and shear line over Chongqing. 2) The moisture conditions during this process were extreme. The convergence of the southwesterly monsoon, the warm and moist airflow on the southwestern flank of the subtropical high, and the peripheral moisture on the northern side of Typhoon “Danas” over Chongqing provided abundant and sustained moisture supply for the heavy rainfall, simultaneously increasing atmospheric instability. 3) A pronounced moisture convergence center was observed between 850 hPa and 500 hPa over Jiangbei Airport, which corresponded well with the region of upward motion. The occurrence of moderate-to-heavy showers with thunderstorms, as well as their duration, corresponded closely in both timing and duration to the abovementioned features.