高原切变线背景下日喀则一次强对流天气过程成因分析

Cause Analysis of a Strong Convective Weather Process in Shigatse under the Background of Plateau Shear Line

摘要: 文章利用NCEP FNL全球再分析资料、日喀则市各气象站逐小时数据、日喀则雷达站资料、FY-2G卫星资料对2023年8月6~7日日喀则市强降水天气进行诊断分析，结果表明：此次强降水天气过程中，高空动量下传作用较为显著，由孟加拉湾输送至我国青藏高原地区的暖湿气流与偏北气流交汇，为强降水的发生发展提供了较为有利的天气形势。低空辐合、高空辐散产生的抽吸作用，利于垂直上升运动的加强和维持，为强降水天气的发生发展提供了较为有利的动力条件。本次对流系统在500 hPa高原切变线东侧生成，发展过程中与多个小对流云团接触融合与高原切变线位置重合，随着高原切变线的发展移动而变化。

Abstract: Based on NCEP FNL global reanalysis data, hourly data of meteorological stations in the Shigatse area, data from the Shigatse radar station and FY-2G satellite data, this paper makes a diagnostic analysis of the heavy precipitation weather in the Shigatse area from August 6 to 7, 2023. The results show that during the heavy precipitation weather process, the downward transmission of high-altitude momentum is more significant. The warm and humid airflow from the Bay of Bengal to the Qinghai-Tibet Plateau of China intersects with the northerly airflow, which provides a more favorable weather situation for the occurrence and development of heavy precipitation. The suction effect caused by low-altitude convergence and high-altitude divergence is conducive to the strengthening and maintenance of vertical ascending motion, which provides favorable dynamic conditions for the occurrence and development of heavy precipitation weather. The convective system was formed on the east side of the plateau shear line at 500 hPa. During the development process, it contacted and merged with multiple small convective clouds and coincided with the position of the plateau shear line, which changed with the development and movement of the plateau shear line.