一次久旱转暴雨天气过程诊断分析

Diagnostic Analysis of Heavy Rain Process After A Prolonged Drought

利用各种实测和计算的气象资料,对陕西省商洛地区2000年6月1～3日出现历史罕见的久旱转暴雨过程进行了详细的分析,结果表明:这次久旱转暴雨过程既与东亚大槽减弱,西太平洋副热带高压增强西伸北抬,西太平洋副热带高压外围的'SW'气流增强等大形势有关,也与低空急流、切变线和不稳定层结的发展等有关,天气转变时各物理量场的变化特征也较明显.暴雨产生在低层高能舌、水汽辐合中心,以及低层辐合高层辐散的上升气流区内.

In this paper, a heavy rain process after a prolonged drought in Shangluo, Shaanxi on 1~3 June, 2000 has been analyzed, utilizing various observed and calculated meteorological data. The results show that the heavy rain process not only related to the circulation on large scale of the weaken East Asia trough and the strengthened and extended westward subtropical high over west Pacific etc, but also related to the local characters like strong lower-level-jet, shear line and straticification unstability. When the heavy rain weather occurred, the heavy rain is located in the area with the high energy tonguein the lower level, the center of vapor convergence, the convergence and ascending center in lower level, and the divergence at the upper level.