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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. In addition, the the uncertainty about these anomalies is also 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) are assigned to the forecast.
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