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投稿时间:2021-12-27 修订日期:2022-06-19
投稿时间:2021-12-27 修订日期:2022-06-19
中文摘要: 综合应用自动站、雷达、卫星、探空等多源观测资料和ERA-5高分辨率再分析资料,详细分析了2020年6月12日江苏高邮EF2级龙卷的天气背景、环境条件、中尺度系统和对流风暴的演变特征,并总结了监测预警经验和预报思考。结果发现:此次高邮龙卷出现在江苏入梅后首场暴雨中,天气形势与2016年6月23日阜宁EF4级龙卷过程有部分相似,具有梅雨锋龙卷典型特征,产生龙卷的对流系统位于500 hPa东移西风槽前,850 hPa低涡西南象限和低空急流左前端,伴有较强对流不稳定能量和较低抬升凝结高度,不同点在于对流有效位能和垂直风切变弱于阜宁龙卷过程;龙卷出现在地面移动的β中尺度低压顶部,处于地面辐合区和暖湿舌内,风暴中心附近辐合急剧增强可能对应于龙卷出现;产生龙卷的风暴具有较长生命史,在龙卷产生前60 min已识别到连续龙卷涡旋特征(TVS),移经高邮湖面风暴加强出现中气旋(M)并与TVS并存8个体扫,龙卷接地前 TVS底高明显下降且切变增强,随时间演变中气旋直径呈“倒梯形”垂直结构、速度切变迅速增强下探,这些雷达特征可作为龙卷临近预警的重要参考。
中文关键词: 梅雨期龙卷,地面散度辐合区,中气旋,龙卷涡旋特征
Abstract:Based on surface automatic observation data, Doppler radar data, Himawari-8 satellite data and ERA-5 high resolution reanalysis data, this paper analyzes the synoptic background, environmental conditions and evolution characteristics of mesoscale systems and convective storms of the EF2 tornado event that occurred in Gaoyou County, Jiangsu Province on 12 June 2020. The monitoring and early warning experience and forecasting thoughts are summarized as well. The results are as follows. The Gaoyou tornado occurred during the first rainstorm process at the beginning of Meiyu in Jiangsu Province. The synoptic condition was partly similar to that of the Funing EF4 tornado on 23 June 2016. The Gaoyou tornado and the Funing tornado both showed up typical characteristics of Meiyu front tornado. The convective system producing tornado appeared in front of 500 hPa westerly trough, in the southwest quadrant of 850 hPa vortex and left side of low-level jet, with strong convective instability energy and low lifting condensation level. But CAPE and vertical wind shear of the Gaoyou tornado were weaker than in the Funing tornado process. The tornado occurred at the top of a moving meso-β scale depression, which was located in the convergence area of surface divergence and the surface temperature warm tongue. The convergence near the center of storm strengthened sharply, which might indicate the tornado. The storm generating the tornado had a long lifetime. Continuous tornado vortex signature (TVS) was recognized 60 minutes ahead. The storm passing through Gaoyou Lake was enhanced. Mesocyclones (M) appeared and coexisted with TVS within 8 radar volume scans. Before the tornado reached the ground, the bottom height of TVS decreased but shear increased significantly. The diameter of the mesocyclone decreased vertically in an inverted trapezoidal structure. The rotation speed shear strengthened, getting to the minimum height. All these features give good indications for the early warning of tornadoes. Based on synoptic-scale system model, meso- and small-scale environmental physical indexes and convective scale storm characteristic evolutions, Jiangsu meteorological departments had a progressive early warning, achieving a successful practice.
文章编号: 中图分类号:P445,P458 文献标志码:
基金项目:国家自然科学基金项目(U2142203)、江苏省气象局2022年度科研项目(KZ202201、KQ202201、BJG202103)共同资助
引用文本:
王磊,王啸华,李杨,张静,王易,吕润清,2023.2020年江苏高邮EF2级龙卷多尺度特征分析和预警思考[J].气象,49(3):291-303.
WANG Lei,WANG Xiaohua,LI Yang,ZHANG Jing,WANG Yi,LYU Runqing,2023.Multi-Scale Characteristic Analysis and Warning Thoughts of EF2 Tornado in Gaoyou County, Jiangsu Province in 2020[J].Meteor Mon,49(3):291-303.
王磊,王啸华,李杨,张静,王易,吕润清,2023.2020年江苏高邮EF2级龙卷多尺度特征分析和预警思考[J].气象,49(3):291-303.
WANG Lei,WANG Xiaohua,LI Yang,ZHANG Jing,WANG Yi,LYU Runqing,2023.Multi-Scale Characteristic Analysis and Warning Thoughts of EF2 Tornado in Gaoyou County, Jiangsu Province in 2020[J].Meteor Mon,49(3):291-303.