Operational Global Modeling Advancements at NCEP: Beta Version of FV3-GFS Parallel Implementation Details and Performance Evaluation

NCEP is implementing beta version of the Finite Volume Cubed Sphere (FV3) dynamic core based Global Forecast System (FV3GFS) into operations in May 2018, which runs in parallel to the current spectral model based operational GFS. This provides a unique opportunity for the users of GFS to have products from two global models running in operations until the planned replacement of operational GFS with an advanced version of FV3GFS in 2019. Accelerated development of FV3GFS was made possible with support from NOAA's Next Generation Global Prediction System (NGGPS) Program. This is a significant milestone for NGGPS and for NOAA's National Weather Service, and signals the creation of NOAA's Unified Forecast System (UFS) centered on FV3 dynamic core for weather prediction at all spatial and temporal scales.

The beta version of FV3GFS is designed to have comparable resolution to the operational GFS with ~13 km horizontal resolution and 64 vertical levels. FV3GFS is configured to run with fully cycled Global Data Assimilation System (GDAS) using current 4D Hybrid EnVar System, and also features a new multi-species 6-class microphysics scheme developed at GFDL (GFDL MP) replacing Zhao-Carr bulk microphysics scheme.

This paper describes details of development and performance evaluation of FV3GFS beta version, and efforts taken to distribute the operational products to the forecasters and users.