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The probability of the forecast to be within one of the 7-anomaly category is calculated by counting of the ensemble members in each category and then dividing by 51, the total number of members. In the example of Figure 2, there is no member in the 3 low anomaly categories, while the 'Normal' category has 2 members, resulting in 3.9% probability, the 'Bit high' category has 13 members, with a probability of 27.5%, the 'High' category has 17 members, with a probability of 33.3%, and finally the 'Extreme high' category has 18 ensemble members, with a 35.3% probability. The inset table in Figure 2 shows the numbers and the probabilitiesnumber of ensemble members with the corresponding probabilities in the 7 categories, but also shows the climatological 'size (' in terms of probabilities ) of the 7 categories. For ease of interpretation, the 7 categories are displayed here with different colours. This highlights, e.g., that the normal flow category's 3.9% probability is much lower than the climatologically expected probability of 20%, however, the three high flow categories have each much higher probabilities than the climatological reference probability, especially the extreme high category, where the forecast probability (35.3%) is more than double the corresponding climatological probability (15%). In addition, the extended 'Near normal' category would have 15 members with 31.4% probability, which is lower than the climatological probability of 50%.
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