Forecasts of historical flu seasons from 1997-1998 through 2013-2014 (excluding 2009-2010) by the optimized five-source surveillance system.

The system includes ILINet, WHO, and three Athena data sources. Forecast performance is summarized in top rows of graphs, by RMSE (red), PWE (green), and PME (blue). The bottom row compares the forecasted (red) and actual (black) times series with 95% credible intervals (gray). Vertical dashed lines indicate the last week of the observational periods, after which all predictor and target data are forecasted.