2007年3月3—5日辽宁特大暴雪过程物理量诊断分析

通过对2007年3月3—5日辽宁历史罕见特大暴雪过程天气形势及物理量场分析,探讨了同期的天气形势特征及相关物理量场与暴雪落区的对应关系。结果表明:500 hPa阶梯槽和地面江淮气旋是此次过程的主要影响系统。对流层中低层辐合、高层辐散及来自2个源地的充沛水汽在有利环流背景下汇合并被抬升是产生暴雪天气过程的主要原因。强降雪出现在850 hPa涡度和200 hPa散度大值区内。温度平流的强弱及冷暖过渡带位置能够较好地反映出降水的强度及落区。

Diagnostic analysis of very heavy storm from March 3 to 5 in 2007 in Liaoning province

Based on the synoptic situation and physical field from March 3 to 5 in 2007 in Liaoning province,the relationships between the characteristics of synoptic situation,the related physical field and the main falling areas of very heavy storm were discussed.The results showed that ladder trough in 500 hPa and Jianghuai cyclone were the key influence systems in this process.Under the background of advantageous circulation,the lower convergence and the upper divergence in troposphere as well as the flush water vapor from two sources were converged and were raised,which were the main reasons causing the heavy storm.The heavy storm occurred in vorticity area of 850 hPa and in large divergence area of 200 hPa.The intensity and falling area of the heavy storm could be reflected by the temperature advection intensity and the cold-warm transition belt location.