Sub-seasonal Predictability of Large-scale Atmospheric Parameters in the Tropical Atlantic Basin

Given that there is utility in ensemble forecasts of synoptic-scale tropical phenomena beyond a week, a natural question is whether these phenomena exhibit predictability out to sub-seasonal time scales. Focusing on lead times between 2-4 weeks, ensemble predictions of quantities such as area averaged vertical wind shear, humidity and sea level pressure produced during the real-time Sub-seasonal Experiment (SUBX) project in 2017 are evaluated and compared to historic data from the European Centre for Medium-Range Weather Forecasts Reanalysis Interim (ERAI). Climatological values of the bulk parameters in SUBX models are compared the climatology in the ERAI to assess biases. Following these evaluations, the ability of various individual models and multi-model ensembles within the SUBX project to capture TC activity is investigated.