Advances Toward an Operational Convection-Allowing Ensemble Prediction System in the Unified Forecast System at NOAA

NOAA plans to unify its numerical weather prediction suite using the Finite-Volume Cubed-Sphere (FV3) dynamical core as the foundation for all operational atmospheric modeling applications. A significant milestone in this process was achieved with the recent implementation of GFS v15, the first system in NOAA’s operational modeling suite to use the FV3 dynamic core, which sets the stage for the Unified Forecast System (UFS).

Following suit, development of convection-allowing applications are underway at the Environmental Modeling Center (EMC) in close collaboration with NOAA Labs (e.g. ESRL, NSSL, AOML, GFDL), partner organizations (e.g. DTC), and wider academic partners. The ultimate goal of this work is the Rapid Refresh Forecast System (RRFS), a convection-allowing ensemble data assimilation and prediction system having rapid updates (≤ 1 hour) - which will be a component of the greater UFS framework.

Progress toward the RRFS with a 3-km Stand Alone Regional (SAR) version of the FV3 dynamic core will be presented with a focus on recent real-time evaluations in testbeds, physics/dynamics testing, advances in data assimilation, and challenges in high performance computing. Plans for the retirement of existing operational regional systems to facilitate the eventual implementation of the RRFS will also be discussed.