2025年11月4~7日伊犁河谷寒潮降水天气过程分析

Analysis of Cold Wave Precipitation Weather Process in Yili River Valley on November 4~7, 2025

摘要: 利用常规气象观测数据、NCEP再分析资料及伊宁站探空数据，对2025年11月4~7日伊犁河谷寒潮降水及复合型灾害天气过程进行诊断分析。结果表明：此次过程是欧亚中高纬两槽一脊环流形势调整背景下，乌拉尔山阻塞高压崩溃、中亚横槽转竖引导强冷空气大举南下，配合南支槽持续水汽输送共同造成的典型秋冬寒潮过程；地面冷高压东移南下与强气压梯度是区域性大风和阶梯式降温的直接原因，500 hPa强冷平流与850 hPa高能假相当位温耦合为雨雪转换提供了关键动力与热力条件，河谷上空强水汽辐合则为持续性降雪提供了充足水汽支撑；伊宁探空温、湿、风垂直结构清晰呈现暖湿积蓄–冷暖交汇–冷层控制–过程消散的演变特征，与降水、大风、降温及风吹雪等灾害的发生发展高度对应。

Abstract: Based on the conventional meteorological observation data, NCEP reanalysis data and Yining station sounding data, the cold wave precipitation and compound disaster weather process in the Ili River Valley on November 4~7, 2025 were diagnosed and analyzed. The results show that this process is a typical autumn and winter cold wave process caused by the collapse of the Ural blocking high and the vertical rotation of the central Asian transverse trough, which leads to the strong cold air moving southward and the continuous water vapor transport of the southern branch trough under the background of the adjustment of the circulation situation of the two troughs and one ridge in the middle and high latitudes of Eurasia. The surface cold high moving eastward and southward and strong pressure gradient are the direct causes of regional gale and stepwise cooling. The coupling of 500 hPa strong cold advection and 850 hPa high-energy pseudo-equivalent potential temperature provides the key dynamic and thermal conditions for the conversion of rain and snow. The strong water vapor convergence over the valley provides sufficient water vapor support for continuous snowfall. The vertical structure of sounding temperature, humidity and wind in Yining clearly shows the evolution characteristics of warm and humid accumulation-cold and warm intersection-cold layer control-process dissipation, which is highly corresponding to the occurrence and development of disasters such as precipitation, gale, cooling and snowdrift.