兰州机场风切变天气过程分析

Analysis of Wind Shear Weather Process at Lanzhou Airport

摘要: 2025年4月26日13:00~16:00，兰州中川国际机场间歇性出现突发性风切变天气，短时间内导致15个航班返航/备降，对航班起降安全构成严重威胁。本文基于当日机场逐小时气象观测报文(METAR/SPECI)、自动观测数据、雷达资料及天气图，系统分析该过程的演变特征与成因。结果表明，此次风切变伴随明显对流活动，期间持续出现积雨云(CB)，风向最大跳变幅度达180˚，阵风峰值达13 m/s，属低空混合型风切变。500 hPa西风急流东移、地面低压系统与地形辐合效应共同提供动力条件，形成“冷顶暖底”不稳定层结，触发对流发展并加剧风场扰动。本文通过多源数据可视化分析，刻画了风切变的时空演变过程，提出应整合激光雷达、自动气象站与积雨云监测信息，构建“观测–识别–预警”一体化机制。研究可为西北复杂地形机场的风切变预报预警及处置提供参考。

Abstract: On April 26, 2025, between 1300 and 1600 local time, Lanzhou Zhongchuan International Airport experienced a sudden wind shear event. Within a short period, this event forced 15 flights to return or divert, posing a severe threat to flight safety. This study systematically analyzes the evolution characteristics and causes of this event based on the airport’s hourly meteorological observation reports (METAR/SPECI), automatic observation data, radar data, and synoptic charts from that day. The results indicate that this wind shear was accompanied by significant convective activity, with persistent Cumulonimbus (CB) clouds observed during the period. The maximum wind direction shift reached 180˚, and the peak gust speed was 13 m/s, classifying it as a low-level hybrid wind shear. The combined dynamic conditions were provided by the eastward movement of the 500 hPa westerly jet stream, a surface low-pressure system, and topographic convergence effects. These factors created an unstable atmospheric stratification characterized by a “cold top and warm bottom”, which triggered convective development and intensified wind field disturbances. Through the visual analysis of multi-source data, this study delineates the spatiotemporal evolution of the wind shear. It proposes the integration of lidar, automatic weather station data, and CB cloud monitoring information to establish a unified “observation-identification-warning” mechanism. This research can provide a reference for wind shear forecasting, warning, and response at airports in complex terrain areas of Northwest China.