Verification of European Storm Forecast Experiment forecasts

The European Storm Forecast Experiment's (ESTOFEX) daily 2006-2009 ordered lightning and severe weather forecasts were analyzed by using a two by two contingency table. Probability of detection (POD), frequency of hits (FOH), probability of false detection (POFD), critical success index (CSI), and bias were calculated. These scores were compared among seasons and years to determine how forecasting skill varied by season, and how it changed from 2006 to 2009. They were also compared among forecasters to determine if some forecasters were more skilled than others. It was determined that severe weather forecasts improved in both POD and FOH scores between 2006 and 2009, Forecasts of lightning, however, did not consistently improve during the forecasting period. It was also determined that ESTOFEX issued superior lightning and severe weather forecasts during the spring and summer, and their forecasts were less successful during fall and winter. The differences in forecasting success, among forecasters, however, was not sufficient to determine if some were more skilled. An analysis of the Relative Operating Characteristics curves (ROCs) of ESTOFEX severe weather forecasts indicated that they were useful for decision-making.