Using ECMWF's Forecasts (UEF2019)

An update is given on the evolution of forecast skill of the IFS as seen in headline and supplementary scores, with emphasis on ensemble forecast performance. Comparison with ERA5 and with forecasts from other global models are made to distinguish the effect of model upgrades from changes in atmospheric predictability. The user-oriented supplementary headline score for 2-m temperature which measures the number of large ENS errors in the medium range is discussed, and a perspective on further reductions in 2-m temperature error is given. The increase in forecast skill expected from model cycle 46r1 is assessed, and new results on the inclusion of observation error in ensemble verification are presented.