一次特大暴雨水汽输送与中尺度分析

从天气背景、水汽输送、中尺度对流系统等几个方面对宿迁2010年9月7—8日出现的特大暴雨过程进行分析。结果表明,偏东风与西南风的切变风场使得水汽在淮北汇合,对特大暴雨的产生非常有利;高低空急流及其耦合作用、不稳定大气层结和冷空气的锲入,能产生深厚的上升运动和快速的水汽垂直输送;中尺度涡旋、低压、流场辐合线或辐合中心对特大暴雨的落区、强度和维持时间有很好的预报意义。

Vapor transport and mesoanalysis of an excessively heavy rain

In this paper we analysed the circulation background, vapor transport and mesoscale convective system of an excessively heavy rain during 7-8 September 2010 at Suqian. The result showed that vapor convergence in Huaibei of Jiangsu due to the shear of east wind and southwest wind was beneficial to the heavy rain. The coupling of lower and upper jet, unstable stratification and cold air intrusion all were able to intensify the upward movement and vertical transportation of the water vapor. Mesoscale vortex, combined with low and airflow convergence, can be used to forecast where and when heavy rain may possibly happen. Also, they have great predictive significance for intensity and duration of heavy rain.