“0185”特大暴雨的诊断分析

对2001年8月5日上海地区的特大暴雨进行了诊断分析。分析表明热力、水汽条件在降水开始前24小时有一定的反映，水汽输送在上海已有大中心形成；动力条件在降水开始前12小时有所反映，中低层大的正涡度中心已移到上海及其附近地区，使上海的不稳定能量得到释放，产生了特大暴雨。另外，中低层的大的正涡度和高空的涡度集中在非常窄的同一地区，是产生特强降水的原因之一。

Diagnosis of Torrential Rain on August 5th 2001

Torrential rain on August the fifth 2001 in Shanghai is diagnosed.Results show that thermal and water vapor background in Shanghai have changed 24 hours before,a water vapor transportation center has also formed.The dynamic condition imposed 12 hour ago,a large positive vorticity center at the middle and low levels also moved above Shanghai and its nearby region,this made instability energy release and formed the torrential rain.Furthermore,large positive vorticity at the middle and low levels and large negative vorticity at the high level overlapped in such a narrow region is also a inducement of the torrential rain.