Spatial maps are produced showing the model-predicted anomalies in seasonally averaged quantities. In most cases both global and regional plots are produced, although global and mid-latitude plots are not publicly available.
Each plot is labeled with the period for which it is valid, e.g. DJF 2006/07 is the three-month period December 2006 - February 2007. The start date of the forecast is given, as is the number of model integrations in the forecast ensemble and the number used to define the climate.
The lead-time in the drop down menus is defined as the time between the forecast start reference date and the start of the verification period.
At the moment the forecast products are released on the 15th day of each month, so the "usable" lead times are half a month less than their nominal values. Plots for
lead times of 1, 2, 3 and 4 months are produced each month. It is good practice to compare the forecast charts for a given target period at different lead times as they become available. The major forecast signals are usually fairly stable, but not always. Weaker signals are subject to appreciable sampling error, and so even if the model signal were to remain unchanged, plots from different months would vary just because of the sampling. The direction of the colour scale generally depends on the field plotted: blue means wet (more precipitation), but also means cold (lower temperatures) or lower pressures. The exception to this is the plots of individual tercile category probabilities and outer quintile (20%ile) category probabilities, which have high probabilities in red regardless of the field or category being plotted.
http://www.ecmwf.int/products/forecasts/seasonal/documentation/system3/ch3.html
Não entendo por exemplo porque é que a Escandinávia ficaria tão quente.
