气象学报2025，Vol.83Issue(5)：1169-1185,17.DOI:10.11676/qxxb2025.20240065
一次飑线翻山增强引发极端大风的观测研究
Observational study of extreme winds induced by a mountain-crossing intensified squall line
摘要
Abstract
Based on dual-polarization radar observations,surface data and ERA5 reanalysis product,an extensive propagation high wind event in Hubei province triggered by squall line is studied.Results show that in the environment with typical thunderstorm temperature and humidity profiles(wet downburst),the squall line originating in Southwest Henan province significantly enhanced after crossing Tongbai mountain,and resulted in a Derecho event in Hubei province.The direct reason for the enhancement of the squall line is that several isolated storms on the south side merged into the squall line.Further analysis reveals that the key mesoscale systems for the enhancement of the squall line included a shallow cold outflow from another squall line,an boundary-layer jet forced by the topography and the cold pool outflow of the squall line.The topographic effects include the blocking of cold pool outflow,the valley penetration of outflow,and the orographic uplift,which triggered isolated storms and provided a mesoscale ascending environment.After the squall line crossed the mountain,extreme winds in Guangshui were mainly caused by downward momentum transfer and divergence of strong downdrafts.The intense convective cells in the squall line were composed of graupels or small hails above the melting layer,and many small solid particles melted into large water droplets or water-covered ice cores near the melting layer.Significant evaporation under the melting layer significantly reduced the diameter of raindrops and liquid water content.This indicates that significant melting and evaporation are the main mechanisms for the formation of strong downdrafts in the storm.The results enhance our understanding of the effects of mesoscale topography on storms and physical processes of the formation of extreme winds.关键词
飑线/极端大风/翻山/双偏振雷达Key words
Squall line/Extreme wind/Crossing mountain/Dual-polarization radar分类
大气科学引用本文复制引用
韦惠红,王秀明,孔海妹,韩汶君,章翠红,孙成龙..一次飑线翻山增强引发极端大风的观测研究[J].气象学报,2025,83(5):1169-1185,17.基金项目
国家自然科学基金项目(U2142203、42375018)、中国气象局复盘总结专项(FPZJ2023-084)、全国暴雨研究开放基金(BYKJ2024Z05). （U2142203、42375018）
