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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 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 is assigned to the forecast.
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