驻马店市一次罕见特大暴雪过程诊断分析

王政

摘 要：本文利用MICAPS常规资料、多普勒雷达产品，对2018年1月3日发生在驻马店的特大暴雪过程进行形势场、物理量、雷达产品分析，得出“天南地北”是驻马店暴雪的典型流场配置。低层东北急流的建立提供了温度条件和水汽补充。西南暖湿气流辐合区与降水带的分布基本一致，逆温层、高层辐散与低层辐合、高层正涡度与低层负涡度的垂直结构提供了动力条件。暴雪区出现在正涡度平流的右前方，正涡度平流中心加强时，暴雪出现一个增幅期且正涡度平流区先于暴雪出现，这对暴雪产生有先兆指示意义。高层辐散、低层辐合的垂直结构先于暴雪发生，也有一定指示意义。

关键词：暴雪;影响系统;动力机制;回波特征;对比

Abstract： This paper used conventional MICAPS data and Doppler radar products to analyze the situation field， physical quantities， and radar products of the blizzard process that occurred in Zhumadian on January 3， 2018， and concluded that "the Flow Field Configuration of Top South Airflow and Lower the North Airflow" was a typical flow field configuration of Zhumadian Blizzard. The establishment of the lower northeast jet provided temperature conditions and water vapor replenishment. The distribution of the convergent area of warm and humid airflow in southwest China was basically consistent with that of the precipitation zone， the vertical structure of inversion layer， high-level divergence and low-level convergence， high-level positive vorticity and low-level negative vorticity provide dynamic conditions. The blizzard area appeared to the right of the positive vorticity advection， when the positive vorticity advection center was strengthened， there was a period of increase in the blizzard and the positive vorticity advection zone appears before the blizzard， which had a precursory indication for the occurrence of blizzard. The vertical structure of high-level divergence and low-level convergence preceded the occurrence of blizzard， and it also had certain significance.

Keywords： blizzard;influence system;dynamic mechanism;echo characteristics;comparison

暴雪是我國常见的灾害性天气之一，会严重影响当地的交通、农业、群众生活。广大气象工作者对暴雪天气的气候特征、环流形势、暴雪成因和形成机理做了大量的研究[1-7]，并取得了很多有价值的成果。赵桂香等[8]认为，通过数值预报产品分析形势演变和物理量诊断分析，不仅可以提前12～24 h进行暴雪预报，而且可以判断暴雪的持续或加强。2018年1月3日和2018年1月24日，河南省南部出现了两次大范围的强降雪天气，豫南部分地区出现了特大暴雪过程，这两次降雪过程都具有范围广、强度大、持续时间长、积雪深度厚的特点，分析两次过程发现，其环流背景相同，但是降雪大致区的位置截然不同，多站日降雪量突破1月历史极值。本文通过对此次特大暴雪过程进行综合分析，分析两次过程降雪位置不同的决定性因素，试图找出对暴雪预报有参考价值的信息，更好地为驻马店的防灾减灾工作服务。……