乌鲁木齐机场2022年夏季1次短时雷雨天气分析

Analysis of a Short-Time Thunderstorm in Urumqi Airport in Summer 2022

本文利用FNL 1. × 1.逐6小时的再分析资料、新疆加密自动站资料、常规气象观测资料及乌鲁木齐机场自动观测资料(AWOS)等,对乌鲁木齐机场2022年6月25日短时雷雨天气特征及成因进行分析,结果表明:1) 500 hPa高空槽带动700 hPa切变东移南压,提供了较好的天气尺度的上升条件,850 hPa始终为偏北风,结合地形抬升作用,大气层结不稳定,地面辐合线的存在,为本次强对流天气的出现提供了背景条件。2) 乌鲁木齐站的抬升凝结高度在850 hPa附近,抬升凝结高度较低的情况下,较小的外力作用就可以将气块抬升形成对流泡。探空层结整体中层湿,高低层干,“上冷下暖”的配置有利于对流不稳定层结的增长。“沙漏”结构有利于雷暴大风的形成。3) 在中阵雨转中雷雨期间,出现了显著的减温增压并伴随明显的风速风向突变的情况,容易造成航班复飞。

Based on FNL 1. × 1. 6-hour reanalysis data, Xinjiang encrypted automatic station data, conventional meteorological observation data and Urumqi Airport Automatic observation data (AWOS), the characteristics and causes of short-time thunderstorm weather in Urumqi Airport on June 25, 2022 were analyzed. The results show that: 1) The 500 hPa upper trough drives the 700 hPa shear eastward to southward pressure, providing better weather scale upward conditions. The 850 hPa is always a northerly wind. Combined with the topographic uplift, the atmospheric junction is unstable and the surface convergence line exists, providing background conditions for the emergence of this strong convective weather. 2) The lifting condensation height of Urumqi Station is around 850 hPa. When the lifting condensation height is low, the gas block can be lifted to form a convective bubble with less external force. The whole middle layer of sounding stratification is wet, the high and low layers are dry, and the configuration of “cool above and warm below” is conducive to the growth of convection-unstable stratification. The “hourglass” structure is conducive to the formation of thunderstorms and gales. 3) During the transition from moderate shower to moderate thunderstorm, there is a significant temperature reduction and pressurization accompanied by an obvious change in wind speed and direction, which is easy to cause the flight to go around.