The AFGL Spectral Model of the Moist Global Atmosphere

The baseline version of the AFGL model of the moist global atmosphere is described in detail. The numerical methods include spectral representation in the horizontal, the Arakawa vertical differencing scheme, and the semi-implicit time scheme. For this version, the pre- and postprocessing, the nonlinear normal mode initialization and the parameterized boundary layer processes and moisture physics are adapted from the NMC spectral model. A series of test forecasts indicate that the model performance is comparable to that of similar large-scale models.