Abstract: Vortices over Tibet Plateau often bring heavy rain and other disasters to China. Generally, they are believed to be generated from bottom to top through sensible heating and latent heating. In this study, however, we find that the May 2013 plateau vortex, which has caused severe precipitation downstream, is actually induced by the synoptic-scale eddies in the upper layer of the troposphere. Using a recently developed functional analysis tools, i.e. the multiscale window transform (MWT), and the MWT-based localized multiscale energy and vorticity analysis (MS-EVA), we reconstruct the ERA5 reanalysis fields into three subspaces of scale, or scale windows, i.e., the basic flow scale window, synoptic scale (plateau vortex scale) window and high frequency window. By the reconstructions, it is shown for the first time that the vortex is generated on the northwestern side of the Plateau, and the generation is through the barotropic instability of the basic flow, i.e., the canonical transfer of kinetic energy from the basic flow window to the vortex scale window, which develops downward from top to bottom. Moreover, the ultimate source of energy for the vortex development is the baroclinic transfer from the basic flow, rather than the non-adiabatic heating as commonly believed. Further analysis shows that there exists a “path” of energy redistribution on the vortex scale window: In the lower layer, the vortex receives available potential energy on the western side, which is then converted into kinetic energy, and transported via vertical pressure work into the upper part. In the upper layer, he kinetic energy on the western side is transported horizontally (via horizontal pressure work) to the east, while the vertical pressure work there carries the gained kinetic energy downward to the lower layer. In doing this the energy received in the lower-western part of the vortex is redistributed throughout, making it possible for an unusually long-duration vortex to develop.