山东一次干线触发极端强对流天气的双偏振雷达分析

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关键词极端强对流；干线;超级单体风暴；双偏振特征；大冰雹

中图分类号：P412.25文献标志码：A 文章编号：2096-3599（2025）03-0096-11

DOI ：10.19513/j.cnki.hyqxxb.20240628001

AbstractUsing the data of conventional observation，FY-2F satelite，S-band dual-polarization radarand ERA5 reanalysis，the circulation situations，environmental parameters，characteristics of dual-polarization parameters and triggering mechanisms of the extremely strong convection weather on 17 May 2020 in Shandong are analyzed. The results are shown below.（1） This extremely strong convective weather occurs underthe background of the northeastcold vortex with the low-level jets and convective available potential energy significantly enhanced at night，the precipitable water and vertical wind shear both exceeding the threshold values in Shandong and suitable height of the 0qC layerand melting level，all of which provide favorable environmental conditions for the extremely strong convection.Hails are locatedin the superimposed area of dryline，strong upward movement and water vapor convergence.（2） The supercell storm formed in Weifang led to the occurrence of the large hails in Changyi，Weifang and the exceptionally large hails in Pingdu， Qingdao.The rapid decrease in the vertically integrated liquid water content during the mature phase of the storm，as well as the descent of the storm topand the centroid of the storm cell， has indicative significance for the hail prediction.（3）The supercell storms that resulted in the different hail sizes between Changyi and Pingdu have distinct dual-polarization characteristics. Both have a large ZH （204号 corresponding to a small ZDR ， Cc and KDP ，as well as strong hail attenuation and beam non-uniform filling characteristics， ZDR arcs in the inflow region and near the mesocyclone，and higher ZDR columns in the updraft area.In comparison with the hails in Changyi，the hails in Pingdu have a larger ZH ，but smaller minima of ZDR and Cc .（4）This strong convective weather process is primarily triggered by the dryline， with convective storms developing violently where the surface convergence line meets the dryline.

Keywordsextremely strong convection； dryline； supercell storm； dual-polarization characteristics;large hail

0 引言

极端强对流天气是指直径超过 5cm 的冰雹、EF2级或以上龙卷、瞬时风速 32m⋅s-1 以上的雷暴大风以及1h内80 mm 或3 h内180 mm以上的强降水[1-2] 。（剩余12918字）