吉林省2007年一次特大暴雪天气过程分析

利用常规观测资料、自动站资料、T213数值预报产品和FY-2C卫星云图产品，运用天气学原理分析方法，从环流背景及环流形势、影响系统、动力条件、能量条件和水汽条件等方面，对2007年3月4-5日的特大暴雪天气过程进行了分析。结果表明，高空南北槽合并配合地面河套倒槽，加之西南急流携带大量水汽北上和水汽的垂直输送是3月4-5日特大暴雪形成的主要原因；另外，低层辐合、高层辐散造成的强烈的上升运动为降雪提供了强大的动力条件，降雪前期的高温为此次降雪积聚了大量的能量，而高值的假相当位温又对不稳定能量的释放提供了很有利的帮助。

Synoptic Analysis of Heary Snow on 4th and 5th March in 2007 in Jilin Provinc

Using routine observational data,automatic meteorological station datasets,T213 numerical forecast products and FY-2C satellite cloud picture,the synoptic characteristics of heavy snow event is researched.The results show that the north and south trough of upper air merged,which is consistent with the surface inverted trough of Hetao area,the massive water vapor being transported by the southwest jet stream and the vertical transfer of water vapor lead to this heavy snow event.The research also indicates that both the convergence in low-level and divergence in upper-level causing intense upward motion,which provides dynamic condition for the heavy snow event,the earlier period's high temperature of this snowfall accumulates massive energy for it,while the higher potential equivalent temperature is favorable for the unstable energy's release.