“2003.1”黔东南暴雪天气过程的对称不稳定分析

Analysis on Symmetric Instability of "2003.1" Snowstorm Event in Southeast Guizhou

采用对称不稳定判据,对发生在2003年1月5～6日一次罕见的黔东南暴雪天气过程进行了分析,结果表明:暴雪产生在对称不稳定大气中,低空急流促使对流层低层暖湿气流辐合上升,触发对称不稳定能量释放,产生暴雪天气.西南涡、横切变和暴雪区有向对称不稳定区移动的趋势.

The symmetric instability criterion is applied to analyze a rare snowstorm weather event in Southewst Guizhou on January 5 - 6, 2003. The result indicates that the snowstorm formed in the symmetric instability atmosphere, the low-level jet triggers the convergence ascending of tropospheric warm and humid airflow and the release of symmetric instability power, thus it appear the snowstorm weather. In the event, southwest vortex, the shear line in east-west direction and the region of snow storm moved towards the area of symmetry instability.