Abstract: The quasigeostrophic barotropic vorticity equation with thermal and topographic terms is used to study temporal evolutions of local flow patterns.Six experiments whose integration times are 72 model days are performed.Results show that various initial fields can creat various approaching behavious such as quasiequilibria,damping oscillations and no-damping oscillations,exhibiting obvious nonlinearity,and that the complexity of the space structure of the thermal forcing plays an important role for the evolution of the local flow patterns.