The Large-Scale Conditions of the Vortex Moving Out of Qinghai-Xizang Plateau

Based on the comparison analysis of general circulation and impacting systems of Plateau vortex moving out or without moving out of the Plateau during 1998—2004 and by using NCEP reanalysis data,the various complexphysical variable fields are calculated to foregoing two conditions in middle and upper levels of troposphere.The research indicates that the Plateau vortex moving out of the Plateau is caused by the interaction of weather systems in westerlies and weather systems of the subtropical zone.It revealed the macroscale condition differences and physical pictureof Plateau vortex moving out of the Plateau,and also revealed the macroscale condition differences of various kinds of Plateau vortexes moving out of the Plateau.It provide the scientific basis for forecasting of heavy rain and flood.