Verification: Assessment of Calibration and Accuracy

In ensemble forecasting, forecast verification methods are needed to diagnose both the need for statistical postprocessing and the effectiveness of the postprocessing methods in producing calibrated and accurate forecasts. This chapter discusses an array of techniques that can be used in this context, making the distinction between verification tools that are useful for ranking competing forecasters and those that are more appropriate for improving our understanding of the performance of a single method. With a focus on continuous variables, verification methods for both univariate and multivariate forecasts are discussed, including approaches that are specifically tailored to the evaluation of extreme events.