内蒙古东北部大雪天气个例诊断分析

Diagnostic Analysis of Super Snow Case in Northern Hunlunbeier

利用常规资料、T213物理量产品,红外云图、湿度图、风廓线,对2009年12月8日、10日夜间造成2次呼伦贝尔北部大雪天气事件环流背景、影响系统及成因进行了诊断分析。结果表明:①2次天气事件发生在前期欧亚地区西风环流控制呈现高指数特征,呼伦贝尔异常偏暖背景下;②影响系统蒙古气旋—东南移动变成倒槽—东北上形成强烈的东北涡;③低层辐合高层辐散在50 N°附近形成降雪动力。

By dint of routine documents,T213 physical quantity products,infrared cloud,humidity chart and wind profile,the circulation background,influence system and causes of snow in the northern Hulunbeier on December 8 and 10 in 2009 were diagnosed.Results suggested that the two weather incidents happened in the early period when the westerly circulation controlling in the European and Asian area showed high exponential characteristics under the background of abnormal warm condition in Hulunbeier;second,influencing system Mongolia cyclone-moving southeastward and turning into trough-forming strong northeast vortex in northeast;third,the low layer convergence high layer forming snowing dynamics around 50°N.