2018年8月2日08时~3日08时暴雨天气诊断分析

Diagnosis and Analysis of the Rainstorm from 8:00 on August 2nd, 2018 to 8:00 August 3rd, 2018

摘要: 本文对2018年8月2日08时~3日08时出现在青海高原东部一次局地暴雨天气进行了诊断分析。分析表明，高短波槽的东移成为了暴雨天气的触发机制；冷空气的入侵是沿西北路径扩散南下，而后由于地形作用倒灌进入高原东部地区；强降水的突发性和局地性都较为明显，具有明显的中尺度特征，卫星云图及雷达回拨都很好地反应了此次过程；水汽源源不断沿着西南气流北上，加之台风的间接影响，其南侧东风气流携带水汽补充，致使水汽辐合中心位于青海高原东部地区；θse高能区和密集带的交界处对强降水的区域预报具有指示性；低层辐合、高层辐散的配置诱发了强烈的上升运动，垂直上升运动有明显的加强过程，并且很深厚，这种深厚的上升运动为这次区域性强降水提供了强烈的动力条件。

Abstract: In this paper, the diagnosis and analysis of a local rainstorm occurred in the eastern part of Qinghai plateau from August 2, 2018 to August 3, 2018 were carried out. The analysis shows that the east shift of the high short wave channel is the trigger mechanism of the rainstorm. The cold air is diffused southward along the northwest route, and then overflows in the eastern part of the plateau due to the action of topography. The sudden and local characteristics of the heavy precipitation are obvious, and it has obvious mesoscale characteristics. The water vapor flows continuously north along the southwest airstream. With the indirect influence of the typhoon, the easterly airstream on the south side carries the water vapor supplement, resulting in the water vapor convergence center located in the eastern part of the Qinghai plateau. The boundary between the high-energy region and the dense zone of θse is indicative for the regional prediction of heavy precipitation. The configuration of convergence in the lower layer and divergence in the upper layer induces a strong upward movement, and the vertical upward movement has obvious strengthening process and is very deep. This deep upward movement provides a strong dynamic condition for this regional heavy rainfall.