ROC Curve for Climatologically-based QPF
The ROC curves are also plotted for the climatologically-generated QPF. These fall very close to the diagonal. The diagonal represents no forecast discrimination skill.
If the curves had fallen below the diagonal, that would indicate negative forecast discrimination skill. In other words, if an observation indicates an event, the forecast had indicated a non-event.
So climatological input results in little or no forecast discrimination skill.
