Evaluation methods for tropical cyclone forecasts: Moving beyond basic metrics

Tropical cyclones are known worldwide to have some of the greatest impacts of all weather events, causing large amounts of damage from wind, extreme precipitation, storm surge flooding, and severe weather. In addition, tropical cyclones provide critical water resources in many areas of the world. Due to these large impacts, accurate prediction of tropical cyclones is a high priority for many weather services, and much effort has been extended toward improving these predictions. Traditional verification of tropical cyclone forecasts has focused on evaluations of the location of the storm center and the storm intensity as measured by the highest wind or lowest pressure associated with the storm. Many challenges are associated with verification of these basic predictions; for example, intensity values typically are inferred from satellite measurements since direct observations of the maximum wind speed are rarely available. Moreover, the “maximum” of any variable is typically very difficult to measure. As evaluations of additional variables (e.g., wind structure) are considered, and as new types of forecasts (e.g., ensembles) are implemented, new verification challenges are being faced. This talk will review current methods for evaluating the various attributes of tropical cyclone forecasts, consider challenges associated with application of these methods, and discuss new tropical cyclone verification approaches that are being developed.