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In order to display the information content of these 51 ensemble rank values, we use a simplified anomaly representation. For this, 5 main anomaly categories were defined by the 10^th, 25^th, 75^th and 90^th percentiles, representing 5 categories of larger anomalies as 'Extreme low', 'Low, 'Near normal', 'High' and 'Extreme high'. For some products (namely the two maps and the hydrographs ), the 5 main categories are used. However, for the probability evolution table in the reporting point popup window product the 5 categories were extended to a 7-category version by sub-dividing the 'Near normal' category into 'Bit low, 'Normal' and 'Bit high' with the 40^th and 60^th percentiles. In the forecasts, each of these 7 categories has a probability value, depending on how many of the 51 ensemble members they contain. 

The overall expected anomaly category of the forecast is defined by the mean of the 51 ensemble member ranks (rank mean), which represents a robust anomaly value without any random jumpiness. The uncertainty about these anomalies is defined using the standard deviation of the 51 ensemble ranks (rank std). Based on this rank standard deviation value, one of three uncertainty categories (low / medium / high) is assigned to the forecast.

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