Unified Forecast System Development and Operational Implementation Plans for Sub-Seasonal to Seasonal (S2S) Predictions at NCEP/EMC

Vijay Tallapragada1, Yuejian Zhu2, Jessica Meixner3, Suranjana Saha4, Avichal Mehra5, Arun Chawla2, Jason Levit6, Ivanka Stajner7, Brian Gross8, Yan Xue9, Dorothy M Koch10 and Farida Adimi11, (1)NOAA/NCEP/EMC, College Park, MD, United States, (2)NOAA/NWS/NCEP/EMC, College Park, MD, United States, (3)Organization Not Listed, College Park, United States, (4)National Centers For Environmental Prediction-Environmental Modeling Center, College Park, MD, United States, (5)National Centers For Environmental Prediction-Environmental Modeling Center, College Park, United States, (6)NOAA/NCEP/EMC, College PARK, MD, United States, (7)NOAA National Weather Service, Boulder, MD, United States, (8)NOAA, NWS/NCEP, College Park, MD, United States, (9)NOAA NWS OSTI Modeling Program Division, Silver Spring, MD, United States, (10)NOAA/NWS, Silver Spring, MD, United States, (11)Office of Science and Technology Integration, Clarksville, MD, United States
Abstract:
NCEP has implemented the first version of the Finite Volume Cubed Sphere (FV3) dynamic core based Global Forecast System (GFS v15) into operations in June 2019, replacing the spectral model based GFS. This is the first instantiation of NOAA's Unified Forecast System (UFS). The next major upgrade is for the Global Ensemble Forecast System (GEFSv12) which will use the same FV3 based global model with advanced stochastic physics perturbations and 2-tiered SSTs, and for the first time, NWS will be providing ensemble based weather predictions for sub-seasonal scales to 35 days. GEFSv12 also comes with 20-year reanalysis and 30-year reforecasts to support stakeholder needs for calibration and validation, and integrates wave ensembles and aerosol capabilities.

NWS is accelerating Subseasonal-to-seasonal (S2S) modeling as part of NOAA’s UFS, consisting of six coupled component models of the Earth system: the FV3 dynamical core for the atmosphere, MOM6 for the ocean, Noah MP for the land surface, GOCART for aerosols, CICE5/CICE6 for sea ice and WW3 for ocean surface waves.

UFS development and operational implementation efforts are centralized and built using community based tools (NEMS, NUOPC, and ESMF). Advancement in model physics and data assimilation are achieved using CCPP and JEDI. The R2O plans are further facilitated through the development of unified workflow and MET+ for verification and validation. All these initiatives involve significant engagement with the research community, with emphasis on research transitioning to operations (R2O).

This talk describes the major challenges in S2S prediction that project onto NWS requirements, and NWS plans and progress in the development of the coupled prediction system with coupled data assimilation for sub-seasonal to seasonal scales. We will also describe the strategy for enabling a robust R2O framework and user support system, and procedures for accelerated transition of advanced community research into operations.