The NOAA Environmental Modeling System at NCEP

Development of the NOAA Environmental Modeling System (NEMS) framework is ongoing at NCEP with its initial operational implementation scheduled for 2011. The NEMS framework in turn has been built using the Earth System Modeling Framework (ESMF). The forecast component of the Global Forecast System (GFS) and the Arakawa B-grid version of the Nonhydrostatic Multiscale Model (NMM-B) are in place. The forecast models share the highest level components of NEMS while having their own Dynamics and Physics subcomponents. An ESMF ensemble stochastic coupler now couples N independent concurrent runs of the GFS Ensemble Forecast System (GEFS) and will eventually govern atmosphere-ocean ensembles using any of the forecast models within the framework. The first operational implementation of NEMS is planned for the Spring of 2011 when the NEMS/NMM-B will replace the WRF NMM in the North American Model (NAM) slot. Four one-way static nests will lie within the NAM domain and an on-call Fire Weather 'grandchild' nest will lie within either the CONUS or Alaska nest as needed. ESRL/GSD is working to incorporate the Finite Element Icosahedral Model (FIM) under the framework. Development also continues on coupling ocean, aerosol, chemistry, and land surface packages within NEMS.