贵州一次秋季暴雨过程的成因及湿位涡诊断分析

Diagnostic Analysis of Causes and Moist Potential Vorticity for an Autumn Heavy Rain in Guizhou

利用常规气象观测资料、区域自动站资料及NCEP 1˚ ×1˚再分析资料对2019年9月7~9日贵州暴雨过程进行成因及湿位涡诊断分析。结果表明:东部沿海维持的低槽对高原槽有明显的阻挡作用,使高原槽在川东至黔西北地区加深为低涡,为贵州中西部连续暴雨提供有利的动力条件;孟加拉湾强烈的水汽输送是此次暴雨产生的重要条件之一;地面弱冷空气持续入侵贵州,为地面辐合锋生提供触发条件;低层MPV1 0是贵州发生暴雨天气的有利形势,MPV1低层负值、高层正值的“垂直叠加”配置形势有利于暴雨的出现。

Based on the data from the conventional meteorological and automated stations, NCEP1˚ ×1˚ rea-nalysis, diagnostic analysis of cause and moist potential vorticity for a heavy rain in Guizhou on September 7-9, 2019, the results show that the rough-maintained along the eastern coast has an obvious blocking effect on the plateau trough, the plateau trough deepens a vortex at eastern Si-chuan and northwest Guihzou, which provides favorable dynamic conditions for continuous heavy rain development in central and western Guizhou;strong water vapor transport from the Bay of Bengal is one of the important conditions for this process. The weak cold air continues to invade Guizhou, providing triggering conditions for surface convergence front generation;lower layers MPV1 0 are a favorable situation for heavy rain in Guizhou. It is a good situation when uphole stack of MPV1 negative value is in lower layers and MPV1 positive value in higher layers.