“09．11”山西罕见大暴雪天气过程分析

2009年11月9日-12日，山西出现了有气象记录以来最强的一次大暴雪天气过程，全省大部分地区降雪量在10mm～66mm之间，其中有86个县市出现历史同期最大值，39个县超过历史极值．本文利用高空、地面和卫星云图资料，对此次过程进行了综合分析，结果表明：高空强盛的西南气流和低层东北气流以及地面回流为暴雪过程提供了有利的流场配置，500hPa同位相槽和700hPa切变线是主要影响系统，低空急流的持续及水汽的辐合为这次暴雪提供了充足的水汽，卫星云图上云顶亮温最低区与强降雪落区有着很好的对应关系。

Analysis of Weather Process of Snowstorm in November 2009 in Shanxi Province

It was the most serious snowstorm in history in Shanxi province in November 9 to November 12, 2009. The snowfall was at between 10mm and 66mm in most of counties in Shanxi province. The snowfall of 86 counties was over the historic maximum in same period. The snowfall of 39 counties was over the historic maximum. The weather process was analyzed based on the data of upper air, surface and satellite image. The results show that the powerful southwest flow in upper air, the low level northeast flow and the backflow of surface provided the favorable flow configuration. The major system was the same phase trough in 500hPa and the shear line in 700hPa. The continued low level jet and water vapor convergence provided the sufficient water vapor for it. The minimum area of satellite cloud top temperature was well relative with heavy snow fall area.