Abstract:

Based on analysis of circulation background, influencing system and the characteristics of physical quantity fields on each layer, the diagnostic analysiswas performed on theweatherprocess of the snowstorm happened inTangshanRegion during3 to4March in 2007 by usingMICAPS data and NCEP 1°×1°6-hour interval reanalyzed data. The results are as follows: the deepening upper trough, the vortex at700 hPa layer and the intensive cold airweremain influencing systems that cause the snowstorm weatherprocess;the divergence athigh level and convergence at low leve,l the enhanced positive vortex, the strong ascendingmotion and thewarm air forced to liftby cold airwere the importantdynamicmechanism of thisweatherevent; the vapour transportcame from the deflection east airstream at the low layer; and theQ-vector convergence at700 hPa correlated to the area of snowstorm’s occurrence, which can be used as an indicator in forecasting snowstorm weather.

Key words: snowstorm, diagnostic analysis, Q-vector, Tangshan

摘要：

在分析环流背景、影响系统及诸层物理量场特征基础上,结合MICAPS资料和NCEP 1°×1°的6 h再分析资料,对2007年3月初唐山暴雪天气过程进行了诊断分析。结果表明,加深的高空槽、700 hPa低涡及东北平原回流的强冷空气是这次暴雪的主要影响系统,降雪期间的高空辐散低层辐、正涡度的增强、较强的上升运动以及冷空气强迫抬升是暴雪发生的动力机制,低层持续的偏东风是主要水汽输送通道, 700 hPa的Q矢量辐合区与降雪落区有较好对应关系。

关键词: 暴雪, 诊断分析, Q矢量, 唐山