2021年11月8日雨雪冰冻灾害天气过程分析

Analysis of the Weather Process of Rain,Snow and Freezing Disasters on November 8,2021

2021年11月7日夜间-9日白天黑龙江省出现大范围雨雪、大风、降温天气。此次天气过程中南部地区雨雪相态转换频繁,出现了罕见的冻雨天气。本文通过对高低空环流演变以及大气温度垂直变化的分析,认为主要是极地冷空气向南爆发的过程中,与低层暖湿空气北上强迫产生斜压不稳定,在地面低压北侧暖锋抬升作用下出现的大范围雨雪天气。分析探空资料可以看出大气边界层起到了冷垫作用,后期地面暖锋沿低层冷垫抬升,大气温度垂直分布出现“上暖下冷”的逆温结构。此外,边界层暖湿平流的输送增加了暖层的厚度,地形影响使“冷垫”作用加强。

From the night of November 7th to the daytime of November 9th,2021,there was extensive rain and snow,strong winds and cooling weather in Heilongjiang Province.During this weather process,the convert of rain and snow in the southern region changed frequently,and there was a rare freezing rain.In this paper,it is believed that the main reason was the southward outburst of the polar cold air and the northward forcing of the low-level warm and humid air to produce instability,and a large-scale rain and snow weather occurs under the uplift of the warm front on the north side of the surface low pressure,through the analysis of the evolution of high and low air circulation and the vertical change of atmospheric temperature.Analysis of the sounding data shows that the atmospheric boundary layer acts as a cold cushion and the ground warm front rises along it,so that,the vertical distribution of atmospheric temperature has an inversion structure of"warm up and cool down".Moreover,the transport of warm and humid advection in the boundary layer increases the thickness of the warm layer,and the topographic effect strengthens the"cold cushion"effect.