新疆地区2024年2月一次强寒潮天气过程分析

Analysis of a Strong Cold Wave Weather Process in Xinjiang in February 2024

摘要: 本文基于NCEP FNL再分析数据、地面气象站实况数据等多源资料，对2024年2月16~17日发生在新疆地区的强寒潮引起的极端降水、大风过程，重点分析了前期气候背景、环流形势、寒潮天气发生的原因等内容，结果表明：异常高温天气为冷空的爆发提供有利的温度基础，天气过程期间极地冷空气持续南压促使极地冷空气在强劲偏北气流引导下不断向南侵袭，为寒潮提供有利的大尺度天气背景。500 hPa环流形势为典型的“里海涨脊、横槽转竖”型，地面冷高压生成于新地岛附近，在地形强迫作用下，冷空气加速下沉，引发动量下传效应，致使北疆和南疆地区出现强西北大风，寒潮爆发呈现出显著的热力和动力条件耦合特征，低层大气同时出现较强的负温度平流、上升运动以及高相对湿度是降雪发生及维持的重要原因。

Abstract: Based on the NCEP FNL reanalysis data, ground meteorological station live data and other multi-source data, this paper analyzes the extreme precipitation and gale process caused by the strong cold wave in Xinjiang from February 16 to 17, 2024, focusing on the previous climate background, circulation situation and the causes of cold wave weather. The results show that the abnormal high temperature weather provides a favorable temperature basis for the outbreak of cold air. During the weather process, the continuous southward pressure of polar cold air promotes the continuous southward invasion of polar cold air under the guidance of strong northerly airflow, which provides a favorable large-scale weather background for the cold wave. The circulation situation at 500 hPa is a typical “Caspian Sea rising ridge and transverse trough turning vertical” type. The surface cold high pressure is generated near Xindi Island. Under the action of terrain forcing, the cold air accelerates to sink and triggers the momentum downward effect, resulting in strong northwest wind in northern and southern Xinjiang. The cold wave outbreak shows significant coupling characteristics of thermal and dynamic conditions. At the same time, strong negative temperature advection, ascending motion and high relative humidity in the lower atmosphere are important reasons for the occurrence and maintenance of snowfall.