沈阳市百年最大降雪过程分析

Procedure Analysis of Hundred-year Largest Snow in Shengyang City

2007年3月4日-5日暴雪过程为沈阳地区有观测资料百年以来最大一次暴雪天气过程。为了研究此次天气的特点，以便于对以后此类天气做出更好的预报，作者在本文中对该次天气过程做了多方面的分析。因为此次天气过程为沈阳市百年以来最大的一次降雪过程，包括暴雪、寒潮和大风三大主要特点，所以对此次过程做一深入的研究对于以后的气象工作具有重大意义。通过分析表明本次过程为高空南北槽合并、低空切变发展为低涡、地面南来气旋和极地冷空气的共同配合作用形成。通过水汽条件、动力因素和k指数等多方面物理量的分析，结果表明此次暴雪、寒潮和大风主要成因为①500hPa强冷空气堆积、700hPa垂直运动、850hPa的低涡和地面南来气旋，高低空以及地面的配合相当完美。②前期暖湿空气的堆积和地面江淮气旋带来的暖湿空气，高空强冷平流。暖湿和冷干空气的交汇是暴雪产生的必要条件。③垂直运动是降水产生的动力因数，垂直运动和地面气旋系统的移动路径和降雪区域密切相关。

Snowstorm procedure from March 4th to 5th ,2007 was the largest hundred - year snowstorm since having the observed data in She-nyang City. In order to research the characteristics of this snowstorm and forecast the more accurate weather forecast of this kind, I analyzed snowstorm procedure of this time at many aspects. The snowstorm was the largest hundred-year snowstorm in Shengyang City including the characteristics of snowstorm, cold wave, strong wind, so making a deeper research of this procedure had a great significant to meteorological work in the future. Analysis showed that this procedure was formed with the common cooperation effects of north-south trough combination in high altitude , low altitude shear developed into cyclone of low whirlpool and ground from south and polar cold air. This article through the various physical quantity analysis of water vapor condition, the dynamic factor and the k index, the results showed that the reasons of storm snow, cold wave and strong wind were：①500 hPa strong cold air piled up ,700 hPa vertical movement, 850 hPa cyclone of low whirlpool and ground from south, high, low altitude and ground perfect cooperated.②Warm moist air piled up at early period and warm moist air from ground Jianghuai cyclone, high altitude strong cold advection. Warm air and cold dry air interface were the necessary conditions for a storm snow.③ Vertical movement was the dynamic factor of Precipitation, the vertical movement and the Mobile Path of ground cyclone system and snow area had close relationships.