In this study, the investigators will address the problem of atmospheric predictability and forecast skill from a phenomenological perspective. Predictability will be analyzed and interpreted in terms of the ability of operational global numerical weather prediction models to forecast the evolution of high-impact weather systems, the large-scale flows in which these are embedded, and the transitions between large-scale flow systems that occur in conjunction with the evolution of selected weather systems. In samples taken from high-resolution ensemble forecasts, case studies for two types of interactions will be diagnosed: tropical-extratropical interactions and arctic-extratropical interactions. In particular, this research will address the physical aspects of the different evolution of ensemble members in the ensemble forecast system. Two graduate students will be involved in this project. The results of this research are expected to translate into improved long-term outlooks and short-term forecasts of high-impact weather events, thereby benefiting operational forecasting and societal activities.
