利用各种观测资料和数值模拟结果, 分析了2009年6月3-4日黄淮地区一次罕见强飑线过程的中尺度动力结构演变特征和发展机理。结果表明， 在稳定的东北冷涡环境下， 冷涡后部与短波扰动相伴的冷平流叠加于对流层低层暖脊之上， 为飑线的发生构建了有利的大气不稳定层结； 飑线的发生\, 发展与地面中尺度辐合线密切相关， 两者相互依存\, 促进； 飑线的移动对应着对流层低层水平涡管的传播。在传播过程中， 水平涡管的倾斜会使垂直涡度向水平涡度转化， 促进飑线的发展； 在飑线发展的不同阶段， 动力结构有显著的差异， 发展成熟阶段的飑线结构具有较强的组织性， 而当其减弱\, 消散时， 动力结构逐渐松散， 各因子间不再有密切的配合， 其特定的对流组织作用就会不复存在。另外， 在飑线的发展过程中， 地面气压场呈明显的中尺度扰动特征， 飑线后部产生的中尺度雷暴高压与风场的辐散中心相伴是地面大风形成的主要原因之一。

Using the various observation data with numerical simulation results, the evolution characteristics and development mechanism of mesoscale dynamical structure in a rare strong squall line process occurred in Huang-Huai area on June 3-4, 2009 are studied. The results show that, companing with shortwave disturbance at the rear of northeast cold vortex, the cold advection are overlapped the warm ridge in lower troposphere under stable environment, which constructs a favorable atmospheric unstable stratification for the occurring of squall line; the development of squall line is closely related to surface mesoscale convergence line, with the relation of interdependence and mutual promotion; the movement of squall line corresponds to the propagation of horizontal vortex tube in lower troposphere. In the propagation process, the inclination in horizontal vortex tube makes transformation of horizontal vorticity to vertical one, which promotes the development of squall line; the dynamic structure of squall line has remarkable difference at each stage of its development. At maturity stage, squall line has clear systematic structure, which is gradually loose with the squall line decreases and dissipates. Factors are no longer closely cooperating with each other, whose specific convective organization would cease to exist. Furthermore, the surface pressure field presents significant mesoscale disturbance characteristics in the development process of squall line. The combination of mesoscale thunderstorm high emerging at the rear of squall line with the divergence center in wind field is one of the main reasons causing the strong surface wind.