一次东北冷涡型暴雪天气过程分析

Analysis of an abnormal northeast cold vortex snowstorm

本文从高空环流背景、地面影响系统、水汽条件及动力条件等方面,对2015年12月2-4日一次冷涡产生的暴雪天气过程进行分析,总结出现此次冷涡型暴雪天气受各层正涡度中心(系统近乎垂直)随着东北冷涡逐步东移至鹤岗市中心,并且偏东气流在鹤岗地区形成小兴安岭的迎风面,地形的抬升导致了上升运动的维持,低涡东南部有一东北西南向的水汽通道,持续输送渤海的暖湿气流,加之偏东气流带来的水汽,在鹤岗市东南部上空形成堆积辐合,为降雪提供了充足的水汽来源,综上因素的作用使降雪量明显增加。

This paper analyzes the snowstorm process caused by a cold vortex on December 2-4,2015 from the aspects of upper air circulation background,ground influence system,water vapor condition and dynamic condition,It is concluded that the positive vorticity center of each layer(system is nearly vertical)moves eastward to the center of Hegang along with the northeast cold vortex,and the easterly airflow forms the windward side of Xiaoxing'an Mountains in Hegang area,The uplift of the terrain leads to the maintenance of the ascending movement.There is a northeast southwest water vapor channel in the southeast of the vortex,which continuously transports the warm and humid air flow from the Bohai Sea.In addition,the water vapor brought by the easterly airflow forms the accumulation and convergence over the southeast of Hegang City,which provides sufficient water vapor source for snowfall.In summary,the effect of other factors on the snowfall has an obvious increase.