2021年岳阳一次混合强对流天气过程成因分析
Cause Analysis of a Mixed Severe Convective Weather Process in Yueyang in 2021
中文摘要：
应用常规气象资料、NCEP逐6 h、逐3 h（空间分辨率为1°×1°）再分析资料和雷达资料等，对2021年5月15日湖南省岳阳市的一次混合型强对流天气过程演变及特征进行分析，并对极大风与强降水中心位置不同进行了简要分析。结果表明：两槽一脊的环流形势下，南支槽、低涡、切变线、冷空气渗入地面倒槽等是天气尺度影响系统；水汽的强烈输送和辐合、“上干冷、下暖湿”的不稳定层结、强垂直风切变是这次强对流天气的有利环境条件。雷达回波的形态特征如三体散射、中气旋、“V”型缺口、中层径向辐合（MARC）、VIL跃增、列车效应等特征对分析和识别强对流天气的种类及强对流天气预警的发布具有重要指示意义。极大风与强降水中心出现位置的不同与水汽辐合的中心位置、垂直运动的强弱以及不稳定能量条件差异有关，与洞庭湖大型水体和临湘东部山区地形的阻挡作用关系密切。
中文关键词：
强对流，环流形势，环境条件，雷达回波特征
KeyWords：
severe convection, circulation situation, environmental conditions, radar echo characteristics
Abstract：
Using conventional meteorological data, NCEP 6-h and 3-h reanalysis data (spatial resolution of 1°×1°) and radar data, the evolution and characteristics of a mixed severe convective weather process in Yueyang City, Hunan Province on 15 May 2021 are analyzed, and a brief analysis of different locations for the extreme wind speed and the heavy rainfall center is carried out. The results show that, under the circulation situation of two troughs and one ridge, the southern branch trough, the low vortex, the shear line, and the cold air infiltration into the ground inverted trough are the synoptic-scale influence systems; the strong transportation and convergence of water vapor, the “upper dry and cold, lower warm and wet” unstable stratification, and strong vertical wind shear are the favorable environmental conditions for this strong convective weather. The morphological characteristics of radar echo, such as three body scattering, mesocyclone, V-notch, mid-level radial convergence (MARC), VIL jump, and train effect are of great significance for the analysis and identification of different types of severe convective weather as well as for the release of severe convective weather warning. The fact that the extreme wind speed and the heavy rainfall center occur at different positions is related to the central position of water vapor convergency, the vertical motion intensity and the difference in the unstable energy conditions. It is also connected to the blocking effect of Dongting Lake, the large water body, and the eastern mountainous areas of Linxiang.