The NOAA Environmental Modeling System at NCEP

The forecast component of the Global Forecasting System (GFS) and the Arakawa B-grid version of the Nonhydrostatic Multiscale Model (NMM) have been placed together under the NOAA Environmental Modeling System (NEMS) framework. This framework in turn has been built using the Earth System Modeling Framework (ESMF). The two forecast models share the highest level components of NEMS while having their own Dynamics and Physics subcomponents. Work is nearing completion on the models' sharing an asynchronous output component that writes history/restart files with NEMS-I/O. An ESMF coupler is being used in the GFS ensemble system to couple N independent concurrent runs. One-way static telescoping nesting is in place for the NMM-B that will be used for high resolution 'windows' in future operational NAM forecasts. Work is ongoing to incorporate additional models from inside and outside of NCEP into NEMS. Efforts are also underway to couple aerosol, chemistry, and land surface packages within NEMS.