A nonhydrostatic vertical-slice model based on a hybrid sigma-theta vertical coordinate has been developed. The slice model is developed as a first step and a test bed for the semi-Lagrangian dynamic core being developed at NCEP/EMC, as a part of the multi-institution Weather Research and Forecasting (WRF) initiative. The model equations are in a flux conservative form on an unstaggered grid. The spatial discretization is based on high-order compact schemes. For time discretization, a low-storage 3rd-order Runge-Kutta scheme is used. A parameter in the hybrid-coordinate definition can reduce the vertical coordinate to a sigma coordinate. Results from preliminary tests will be presented.