Facilitating Development of Physical Parameterizations for NOAA's Unified Forecast System

The National Centers for Environmental Prediction (NCEP) has decided to adopt a modularized system architecture for its new Unified Forecast System (UFS), which will be transitioned gradually to operations within the next few years. Applications of the UFS will range from analysis and nowcasting to weather and subseasonal prediction, encompassing both global and limited-area configurations, in deterministic and ensemble forecast mode. While the dynamical core for the UFS has been selected to be the Finite-Volume Cubed Sphere (FV3) developed by NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL), the physics suites for the various applications are currently under review.

The Global Model Test Bed (GMTB) within the Developmental Testbed Center was established by NOAA’s Next Generation Global Prediction System (NGGPS) program to facilitate the community involvement in the process of developing and testing advanced physics. Much of the GMTB work to date has been devoted to the development of the Common Community Physics Package (CCPP; see attached figure), which encompasses a library of physical parameterizations envisioned to contain operational and developmental parameterizations (the CCPP-Physics), as well as a framework that connects the parameterizations to host models (the CCPP-Framework).

The CCPP-Physics and its associated CCPP-Framework are developed as open source codes and freely distributed through GitHub. The first public release of CCPP took place in April 2018. This package included all parameterizations of the current operational GFS, and the ability to connect to the GMTB Single Column Model. Since then, additional parameterizations have been added to the CCPP and the code is undergoing integration with the UFS. In this presentation we will describe the CCPP public release and its progress in transition to operations. Additionally, we will discuss a hierarchical model testing framework that is being put in place to assess the performance of the physics schemes and of the physics suite as a whole using tools ranging from the GMTB SCM to a workflow for fully cycling the UFS with data assimilation.