Recent Numerical Weather Prediction Implementations and Progress toward a Unified Forecast System at NCEP
Numerical model development at the National Centers for Environmental Prediction (NCEP) Environmental Modeling Center (EMC) has been rapidly evolving in recent years with efforts to simplify the NCEP Production Suite around a unified set of modeling components and common infrastructure. Led by the transition to the Finite-Volume Cubed-Sphere (FV3) dynamical core as the cornerstone of future atmospheric modeling efforts, an initial success in this endeavor occurred in summer 2019 with the implementation of the FV3 dycore into the Global Forecast System. Moving forward, the NCEP Production Suite will be underpinned by the Unified Forecast System (UFS), which will include ~8-10 modeling applications focused on predictions at specified spatial and temporal scales ranging from medium- and extended-range, global predictions to short-term, local/regional analysis and prediction.
NCEP and the National Weather Service as a whole are in the midst of a particularly intensive year of implementations with more than a dozen models, including atmospheric, ocean, wave, and hydrologic prediction systems, having been recently upgraded or planned for upgrade in the coming months. Some of these implementations, including the Global Ensemble Forecast System version 12 (GEFSv12) and the High Resolution Ensemble Forecast version 3 (HREFv3), take initial steps toward incorporating the FV3 dynamical core into new areas of the NCEP Production Suite. Others, like the Rapid Refresh version 5 (RAPv5) and the High Resolution Rapid Refresh version 4 (HRRRv4), will be the final upgrades to legacy modeling systems prior to their eventual retirement with the planned implementation of various UFS applications.
Over the last 12 months, the Model Evaluation Group (MEG) at EMC led official evaluations for the proposed implementations of the Global Forecast System version 16 (GFSv16) and the aforementioned modeling systems. These official evaluations served as opportunities to conduct final validations of the experimental configurations and to communicate expected strengths and concerns to NCEP’s customers and stakeholders prior to operational implementation. Highlights of these official evaluations along with a brief discussion of future plans will be presented.
