冷涡背景下飑线过程发生前环境场分析

Environmental Field Analysis before the Occurrence of the Squall Line Process in the Cold Vortex Background

摘要: 本文利用NCEP再分析资料，对冷涡背景下有飑线和无飑线进行对比分析，得出以下结论：1) 有飑线发生的冷涡各层系统的配置有利于引发对流天气。2) 飑线发生前6 h各层的水汽条件比较好。3) 飑线发生前6 h，对应地区上空气流在中低层气旋性旋转，在高层反气旋性旋转，低层辐合高层辐散，这种配置非常利于强对流的形成。无飑线发生日对应地区则为低层辐散高层辐合，不利于对流发生。

Abstract: In this paper, the NCEP reanalysis data is used to compare and analyze the squall line and the no squall line in the cold vortex background, and the following conclusions are drawn: 1) The configuration of the cold vortex system with the occurrence of the squall line is conducive to convective weather. 2) The water vapor conditions of each layer 6 h before the occurrence of the squall line are better. 3) 6 hours before the occurrence of the squall line, the air flow in the corresponding area rotates in the middle and lower layers, and the anti-cyclonic rotation in the upper layer and the high-level divergence in the lower layer are very favorable for the formation of strong convection. The corresponding area of the occurrence of the no squall line is the low-level divergent high-level convergence, which is not conducive to convection.