Physical Diagnosis Of .2003.7.30 Qinghai Province ~ Rainstorm Analysis

Conventional soundings and satellite cloud maps are used to investigate the heavy rain events in east part of Qinghai province during July 29-30, 2003. The analysis results shows that main influential system of the rainstorm are the northward motion of Qinghai-Tibet Plateau depression and the warm moist air, and the dry cold air from Xinjiang region. Over the area of heavy rain, there is the maximum of vertical speed , and divergence at the higher level , and convergence at the lower level. The article point out that the downward transport of the high moist potential vorticity from high level causes the development of low level cyclone .The rainfall may occur near the south area of positive center of MPV1 and negative region of MPV2 at 500hPa.