贵州一次梅雨锋西段暴雨成因分析

Analysis of a Meiyu Front Rainstorm in the West Guizhou

摘要: 利用常规观测资料、区域自动站及NCEP再分析资料，对2014年7月3日贵州暴雨天气过程成因进行诊断分析。结果表明：高空急流形成强的“抽吸”效应对暴雨过程的维持和发展起着主导作用。槽前及副高西侧的偏南暖湿气流不断向长江流域一带输送与北方南下的干冷空气交汇形成准静止锋；西南涡发展和西南急流增强，暴雨发生在高空急流入口处右侧辐散区以及低空急流左侧和切变线的右侧强辐合区。此次暴雨的水汽来源主要来自孟加拉湾和南海，水汽辐合中心与强降水落区基本一致，水汽通量及其散度对强降水落区有一较好的指示意义。

Abstract: Based on the conventional observation data, the regional automatic station and NCEP reanalysis data, the causes of the formation of the rainstorm weather in Guizhou in July 3, 2014 were analyzed. The results show that the strong wind jet stream in the North West of 200hPa is strong, and the "pumping" effect on the formation of the heavy rain process plays a leading role in the maintenance and development of heavy rainfall. Front of 500 hPa trough, the southwest warm wet air current and the west side of the subtropical high southerly warm moist air flow continuously to the drainage area of the Changjiang River Transportation cool dry air from the north and south of the convergence of quasi stationary front, the rainstorm occurred when frontogenesis intensifies; low-level southwest vortex development, enhance the southwest jet and rain storms occur scattered area and the low altitude of the left side of the jet and shear line on the right side of the strong convergence zone in upper level jet entrance on the right side of the web. The rainstorm water vapor source mainly comes from the bay of Bengal and the South China Sea, the bay of Bengal have low value system, with the Western Pacific subtropical high is weakened back East, on the west side of the partial southerly water vapor transport is enhanced, and the southwest airflow rendezvous was transferred to Guangxi, Guizhou, the Yangtze River Basin, is conducive to the occurrence of heavy rainfall, water vapor convergence center of strong precip itation area consistent, the water vapor flux and its divergence of strong precipitation area has a good indication.