东北冷涡影响下锦州地区特大暴雪灾害天气成因分析

Analysis of the Causes of Extreme Snowstorm Disaster Weather in Jinzhou Region under the Influence of the Northeast Cold Vortex

摘要: 应用常规气象观测资料、多普勒雷达资料、EC再分析资料，对2021年11月7~9日锦州地区出现的极端降雪过程成因分析，结果表明：此次降雪为锦州地区有气象记录以来最强降雪。主要受500 hpa东北冷涡强烈发展诱发低层低涡及地面气旋发展北上、700 hpa低空偏南急流、切变线、能量锋发展、维持以及850 hpa以下冷垫形势背景下的降雪。强降雪分二个阶段，7日03时至8日03时，为锋区持续强降雪，8日4时至9日5时为气旋本身弱降雪。降雪过程地面温度先降后升，由冷空气从低层楔入后被南来暖湿气团取代所致。925 hpa以下存在冷垫，925~870 hpa存在明显逆温层，870 hpa以上为冷层，这种冷–暖–冷结构，提供的动力、热力、水汽条件，引发锦州地区出现罕见“雷打雪”现象。

Abstract: Using conventional meteorological observation data, Doppler radar data, and ECMWF reanalysis data, this study analyzes the causes of the extreme snowfall event in Jinzhou from November 7 to 9, 2021. The results indicate that this snowfall was the most severe on record in Jinzhou. It was primarily driven by the intense development of a 500 hPa Northeast Cold Vortex, which induced the northward movement of a low-level vortex and surface cyclone. Additionally, factors such as the 700 hPa low-level southerly jet, shear line, energy front development and maintenance, and a cold cushion below 850 hPa contributed to the snowfall. The heavy snowfall occurred in two stages: the first (03:00 on the 7^th to 03:00 on the 8^th) was sustained heavy snowfall in the frontal zone, while the second (04:00 on the 8^th to 05:00 on the 9^th) featured weak snowfall from the cyclone itself. Surface temperatures initially dropped and then rose due to the replacement of cold air wedging into lower layers by warm, moist southerly air masses. A cold cushion existed below 925 hPa, with a distinct inversion layer between 925 hPa and 870 hPa, and a cold layer above 870 hPa. This “cold-warm-cold” vertical structure provided dynamic, thermal, and moisture conditions, leading to the rare “thundersnow” phenomenon in Jinzhou.