The NCEP RSM is a limited-area atmospheric numerical model for weather simulations and predictions. It was developed fully inside the NCEP based on the structure of the NCEP global spectral model, called MRF or AVN.

The dynamic system can be hydrostatic or nonhydrostatic. The horizontal difference is computed by spectral computation with perturbation method. The vertical difference is computed by finite difference method. The model physics are used full package from those in the MRF. They are radiation, surface energy budget, planatary boundary layer physics, gravity wave drag, shallow convection, cumulus convetion, large scale precipitation, and soil model. For the sake of appling to mesoscale conditions, some mesoscale physics are added or planned to add, such as prognostic cloud scheme.

The model structure is the same as the MRF model. All the routines are very much plaugible and portable to any machine. It is running on different platform, such as Cray C90, Cray J90, IBM risc, DEC alpha, HP UX, SUN sparc, and SGI indy etc.