冷涡背景下一次阵风锋与海风锋碰撞触发强对流的观测分析

Observation and Analysis of a Strong Convection Triggered by a Collision between a Gust Front and a Sea Breeze Front under the Background of a Cold Vortex

摘要: 利用常规观测资料、NCEP/FNL再分析资料、多普勒雷达资料等，对2023年8月16日厦门市的雷暴天气进行分析，结果表明：此次雷暴天气发生在冷涡后部西北气流中，高低空温度差动平流加强了不稳定层结，高CAPE值和0~6 km弱垂直风切下，在阵风锋与海风锋碰撞区域形成脉冲风暴，具有爆发性强对流的典型特征。触发的新生对流沿着海风锋自东北向西南发展加强给闽南地区带来较大范围、较长时间的强降水天气；通过此次雷暴个例分析可知，沿海地区的预报员加强地面辐合线推移和演变的监测，一定程度上可以提前判断出多条辐合线碰撞触发新生对流，由此对此类强对流天气提前作出预报决断。

Abstract: Using conventional observation data, NCEP/FNL reanalysis data, Doppler radar data, etc., an analysis was conducted on the thunderstorm weather in Xiamen on August 16, 2023. The results showed that the thunderstorm occurred in the northwest airflow behind the cold vortex, and the high and low altitude temperature differential advection strengthened the unstable stratification. Under high CAPE values and weak vertical wind shear of 0~6 km, a pulse storm was formed in the collision area between the gust front and the sea breeze front, with typical characteristics of explosive strong convection. The newly triggered convection develops and strengthens along the sea breeze front from northeast to southwest, bringing large-scale and long-term heavy precipitation weather to the southern Fujian region. Through the analysis of this thunderstorm case, it can be seen that forecasters in coastal areas can strengthen monitoring of the movement and evolution of ground convergence lines, which can, to some extent, predict in advance the collision of multiple convergence lines triggering new convection, and thus make forecast decisions for such severe convective weather in advance.