ECMWF-IFS and fvGFS Forecast Skill with the Same Initial Conditions

In a collaboration between NOAA/GFDL and ECMWF, the GFDL fvGFS model has been initialised with the ECMWF analysis for a set of dates in the past. The fvGFS model has also been initialised with the GFS analysis for the same set of dates. This gives 2 sets of forecasts with the same (FV3) model but different initial conditions and 2x2 sets with same initial conditions (including the GFS operational forecasts). These pairs of forecasts give the opportunity to disentangle the impact of errors from initial conditions and from the model, and also to get a better understanding of some systematic errors. The collaboration also includes comparisons of forecasts for tropical cyclones. In this presentation we will give example of the impact on mean errors, correlation of forecast busts and hurricane performance.