一次低涡造成的南宁机场强对流天气过程分析

Analysis of a Strong Convection Weather Process Caused by a Low Vortex at Nanning Airport

摘要: 本文利用EC再分析资料ERA5 (0.25˚ × 0.25˚)、风廓线雷达资料、自动气象观测站资料、探空资料，对2024年5月19日南宁吴圩国际机场发生的强对流天气过程进行分析。结果表明：(1) 高空短波槽东移、中低层低涡切变系统活动与地面冷空气南下共同作用，是此次强对流天气的主要触发条件；(2) 低层湿舌北伸与偏南暖湿气流持续输送，为对流发展提供了充足的水汽供应和辐合抬升条件；(3) 南宁机场探空“上干下湿”的垂直结构，有利于对流不稳定能量积累与释放；(4) 低层辐合与高层辐散形成的垂直抽吸效应，是此次对流天气维持、发展并增强的关键动力机制。

Abstract: This article analyzes the severe convective weather process that occurred at Nanning Wuwei International Airport on May 19, 2024, using EC reanalysis data ERA5 (0.25˚ × 0.25˚), wind profile radar data, automatic weather observation station data, and sounding data. The results show that: (1) The eastward movement of the high-level shortwave trough, the activity of the low-level low vortex shear system, and the southward movement of cold air on the ground are the main triggering conditions for this severe convective weather; (2) The northward extension of the low-level wet tongue and the continuous transport of warm and humid air towards the south provide sufficient water vapor supply and convergence lifting conditions for convective development; (3) The vertical structure of “dry on top and wet on bottom” sounding at Nanning Airport is conducive to the accumulation and release of convective unstable energy; (4) The vertical suction effect formed by low-level convergence and high-level divergence is the key driving mechanism for the maintenance, development, and enhancement of this convective weather.