In this paper,the nonlinear gravitational waves in a baroclinic atmosphere are studied.It is found by use of the WKB method that the interaction between two wave packets is governed by coupled nonlinear schrödinger equations and the immobile wave may occur.It is shown by numerical calculations that the waves amplify and the width of waves becomes narrow after the collision or chase of two solitary gravitational waves.The results indicate that the nonlinear interaction between the gravitational waves may be one of the causes for the outbreak of severe convective weather.