Figure 7 shows the annual mean RPSS scores of the 500-hPa geopotential heights verified over the Northern Hemisphere.
Of the three operational NCEP/GEFS ensembles, the one with optimal bias correction (OPR_OPT) gets the highest RPSS scores among the six curves. The decaying average bias-correction algorithm also works well. The RPSS of the OPR_DAV2% is improved versus the OPR_RAW for all lead times, but especially in the short range, which can be judged from the small distance between the two curves OPR_DAV2% and OPR_OPT.