一次东北暴雪天气过程诊断分析

利用Micaps系统的实况资料,应用天气学分析及物理诊断分析方法,对2007年3月3~6日东北地区特大暴雪天气过程进行环流形势、物理量场诊断分析。结果表明:南方气旋东移北上强烈发展和500 hPa南北2支高空槽合并是造成该次强降雪的主要影响系统。700 hPa偏南低空急流为东北地区产生暴雪提供了充足的水汽来源;低空辐合、高空辐散配置形势的强烈抽吸作用以及低空急流和切变线的耦合作用为暴雪提供了强有利的上升动力条件;强冷空气东移南下与暖湿空气的交绥作用,使得系统强烈发展,触发了强降雪的发生。

Diagnostic Analysis of a Snowstorm Process in Northeast China

Based on the observed data from Micaps system,the diagnostic analysis of circulation situation and physical quantity field was made on the exceptional snowstorm weather process in Northeast China in Mar 3rd-6th,2007.The results showed that the strong development of southern cyclone shifting from southwest to northeast and the combination of northern and southern branches of upper trough at 500 hPa were the main influencing systems of this snowstorm.Southern low-altitude jet stream at 700 hPa supplied sufficient water vapor source for snowstorm in Northeast China.Strong pumping action of disposal situation of lowaltitude convergence and high-altitude divergence and the coupling effect of low-altitude jet stream and the shear line provided favorable rising power.The southeastern shifting of strong cold air and the conflict of warm moist air made the system develop intensively and triggered the occurrence of snowstorm.