Headwater Box Plot, Low Flows, Hour 30

Here, looking at the zoomed area representing the lowest 80% of observed flows, the ensemble forecast distributions are mainly above the zero error line. This indicates that the ensemble spread has too many high values. In other words, the forecast system is tending toward an overforecasting bias.

Zoomed Box Plot of 30-hour Ensemble Forecast Errors Against Observed Value for Headwater Point at Williamsburg