The
output of an ensemble prediction system is a set of forecast values for each
projection time and for each point in the model domain. The set of forecast
values is intended to represent an estimate of the distribution of possible
outcomes at the valid time. The
evaluation of distributions of forecast values presents challenges to forecast
verification methodology and has led to the extension of the “toolbox” of
verification techniques.
Verification methodology for ensemble forecasts is directed toward two main purposes: The diagnostic assessment of the characteristics of the ensemble distribution, and the verification of probability forecasts derived from the ensemble. More recently, a third purpose has emerged: the assessment of value or potential value of probabilistic ensemble forecasts. This paper presents a brief survey of new verification methods that have been developed specifically for application to ensemble forecasts.