2023年12月旅顺连续降雪过程分析
Analysis of Continuous Snowfall Process in Lvshun in December 2023

本文对2023年12月旅顺出现的连续10天强降雪天气事件进行回顾，运用多个站点观测资料、ERA5的位势高度场、海表温度场、中央气象台的天气形势图与近10年12月连续降雪事件加以对比总结，结果表明：2023年12月平均的冷涡强度最强(中心强度为5080位势米)，强大的冷涡以及极为偏东的高空冷空气堆积是此次连续降雪事件的主要系统；渤海海峡的等温线分布有一个明显的向渤海以北延伸的暖舌(5.2℃~7.6℃之间)，平均海气温差在9.4℃，这样冷空气在经过上游暖舌区域增温增湿后可给辽东半岛带来冷流降雪；此次连续降雪既有系统性降雪，又有冷流性降雪，其中冷流降雪(旅顺地区风速小)，850 hpa或700 hpa分别处在涡后或槽后脊前，系统性降雪，500 hpa、700 hpa我区均处于高空槽前，850 hpa处于槽后脊前；冷流降雪前及过程中，辽东半岛北部中低空都出现了明显的垂直运动、水汽输送、水汽辐合，700 hpa相较850 hpa更为明显。
In this paper, the 10 consecutive days of heavy snowfall in Lvshun in December 2023 was reviewed, and the observation data of several stations, the geopotential height field of ERA5, the sea surface temperature field, and the weather situation chart of the National Meteorological Center of CMA were compared with the continuous snowfall events in December in recent 10 years. The results show that: In December 2023, the average intensity of the cold vortex is the strongest (the central intensity is 5080 geopotential meters), and the strong cold vortex and the accumulation of high altitude cold air very far to the east are the main systems of this continuous snowfall event. The isothermal distribution of the strait has an obvious warm tongue (between 5.2？C~7.6？C) extending to the north of the Bohai Sea, the average temperature difference between the sea and the air is 9.4？C, so that the cold air can bring cold flow snow to the Liaodong Peninsula after warming and humidification in the upstream warm tongue area. The continuous snowfall has both systematic snowfall and cold flow snowfall, among which cold flow snowfall (low wind speed in the Lvshun area), 850 hpa or 700 hpa are behind the vortex or in front of the rear ridge of the trough, and systematic snowfall, 500 hpa and 700 hpa are in front of the upper trough, and 850 hpa is in front of the rear ridge of the trough. Before and during the cold current snowfall, there are obvious vertical movements, water vapor transport and water vapor convergence in the middle and low levels in the northern part of the Liaodong Peninsula, the phenomenon is more pronounced at 700 hpa than 850 hpa.