In the next lines we describe an illustrative example considering  one-month lead time forecasts of minimum surface temperature for January over a window centered in Europe ---0$^{\circ}$W -- 30$^{\circ}$E and 35$^{\circ}$S -- 65$^{\circ}$N---. A more ellaborated example describing a multi-model selection of a similar dataset will be further developed in Appendix~\ref{app1}.