Week 2 Forecasts in High Resolution Prototypes of NOAA/NCEP’s Future GFSv17

NOAA/NCEP/EMC is in the process of developing an upgrade of the current operational Global Forecast System, GFSv16. The operational GFSv16 is a global deterministic forecast model with the wave model one-way coupled to the atmosphere model, and prescribed ocean and sea ice forcing, whereas the next version, GFSv17, will be a coupled atmosphere, land, ocean, sea-ice, and wave model. Building on the previously conducted lower resolution Global Coupled UFS Prototypes 1–8, high resolution prototypes targeting GFSv17 are formulated and tested. The prototype development is iterative: results from their evaluation guide model revisions to reduce systematic bias and errors for subsequent prototypes. In this presentation we will discuss the high resolution prototypes to date targeted for GFSv17 that have been developed and tested over a consistent set of dates in recent past seasons. We will present a comparative evaluation of week 2 forecast skill metrics relative to the operational GFSv16. Evaluations will focus on sensible weather elements, radiative fluxes, upper air circulation, MJO, and tropical cyclone tracks and intensity. We will demonstrate the attained progress in reducing forecast errors and improving skill, highlight remaining challenges, and discuss directions for further improvement.