乌鲁木齐机场2025年11月一次降雪天气过程分析

Analysis of a Snowfall Weather Event at Urumqi Airport in November 2025

摘要: 对2025年11月5~6日乌鲁木齐机场一次雨转雨夹雪转雪的天气过程进行分析表明，此次过程500hPa上受槽前西南气流影响，地面冷空气源地在新地岛一带，北方路径入侵；850 hPa以下为水汽辐合、700 hPa以上为水汽辐散，低层高比湿区较厚，为降水提供了充沛水汽；中低层深厚的上升运动与冷平流的侵入在时间上高度吻合，同时，由于冷平流的持续侵入导致低层逆温层减弱消失，是降水相态转为持续性降雪的重要前兆。

Abstract: Analysis of the weather event from November 5 to 6, 2025, at Urumqi Airport—characterized by a transition from rain to sleet and then to snow—reveals that the system was influenced by a southwest airflow ahead of a trough at the 500 hPa level, with cold air originating from the Xindao Island region and moving in from the north. Moisture convergence occurred below 850 hPa, while moisture divergence took place above 700 hPa, resulting in a thick layer of high specific humidity near the surface, providing ample moisture for precipitation. Strong vertical ascent in the mid- to lower troposphere coincided closely in time with the intrusion of cold advection. The continuous penetration of cold advection weakened and eventually eliminated the inversion layer, serving as a key precursor to the shift in precipitation phase toward sustained snowfall.