Strategies for the verification of ensemble weather element forecasts

Laurence J. Wilson

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Meteorological Service of Canada

Ensemble forecasts present distributions of forecast weather elements valid for each location and projection time. The meaningful verification of these forecasts against observations calls for the design of new verification measures, or at least the careful redesign of existing verification methods. Verification methods for ensemble forecasts are of two types: those which are intended to assess one or more aspects of the quality of the whole ensemble distribution, and those which evaluate probability forecasts extracted from the ensemble distribution.

This presentation comprises a survey of both aspects of ensemble verification, and will be illustrated with examples of the assessment of the Canadian ensemble forecasts and those from ECMWF.