4 and show that while forecast reliability is good for days 4-11, it quickly drops to a flat line in the reliability diagram for days 12-18 onward, indicating no useful forecast reliability on these time scales.
As discussed in the previous section "Forecast reliability," an initial-value reliability diagram does not only indicate whether the model is able to capture the predictable features of the event under consideration, it also indicates whether the model can predict climatological probabilities in situations where the event is unpredictable.
The reliability diagram provides a simple framework for calibrating probabilities to make them (in sample) reliable.
The reliability diagram associated with the idealized MODEL of REALITY for the six sets of initial conditions A-F.
(2016) discuss, but largely discount, the use of initialized seasonal forecast reliability diagrams for assessing the ability of a particular climate model to be used for extreme event attribution.
Examples of actual reliability diagrams from a state-of-the-art numerical weather prediction MODEL are given below.
(2016) comment in the introduction: reliability diagrams do not only test the ability of models to capture the predictable features of the event under consideration, they also test the ability of the model to predict reliably the situations where there is no predictable signal, that is, by producing an ensemble probability equal (within sampling uncertainty) to the climatological frequency of the event.
In this section, we discuss and present some reliability diagrams on seasonal and subseasonal time scales from the ECMWF operational system to assess the reliability of initialized ensemble forecasts performed with complex state-of-the-art coupled ocean-atmosphere models.
Nowadays, the ASG previsional reliability is evaluated (Billinton & Allan, 1987; Felea & Coroiu, 2001; Patrick & O'Connor, 1991) basing on its structure (Kostenko & Piotrovski, 1979), representing the equivalent reliability diagram
, the event tree, failures or the states graph, indicating the reliability indices.