A Comparison of the Predictability of Arctic and Atlantic Basin Cyclones

Previous research has suggested that Arctic cyclones can lead to rapid declines in sea ice during the summer. As a consequence, it appears that sea ice predictions are predicated on being able to predict cyclone-related wind speed and direction, which critically depends on the cyclone track and intensity. Despite this, there are relatively few studies that have documented the predictability of Arctic cyclones during the summer, beyond a few case studies, nor has there been an extensive comparison of whether these cyclones are more or less predictable relative to midlatitude cyclones, which have been studied in greater detail. The goal of this study is to document the predictability of Arctic cyclone position and intensity forecasts over a large number of cases and compare it to Atlantic basin midlatitude cyclones using the Global Ensemble Forecast System (GEFS) Reforecast V2. This dataset contains 11-member ensemble forecasts initialized daily from 1985-present using a fixed model. Here, predictability will be defined as the ensemble standard deviation. In this presentation, we will document the methods used to identify cyclone cases in both basins and compare the position and intensity predictability as a function of time before cyclogenesis occurs.