Observed and Modeled Trends in Subseasonal-to-Seasonal Tropical Cyclone Predictability

Subseasonal to seasonal (S2S) tropical cyclone prediction, prediction at lead times between 2 weeks to 2 months, is important for preventing disasters, safeguarding livelihoods, and disseminating early warnings for imminent storm activity before and during the hurricane season. Recent projections of global tropical cyclone (TC) activity indicate a likely global increase in the frequency and variability of the most intense TCs under global warming. Concurrently, global warming is expected to increase the variability in two key sources of S2S TC predictive skill - the Madden Julian Oscillation and El Niño Southern Oscillation. But do the robust variability trends observed in both TCs and S2S climate phenomena have any impact on future TC predictability? While many studies have examined future projections in TC activity, little research focuses on how these future changes may impact the S2S environmental variability and our ability to predict subseasonal TC activity. Therefore, we examine trends in S2S TC predictability for both present and future climates using reanalysis data and the PRIMAVERA High Resolution Model Intercomparison Project (HighResMIP), a multi-model ensemble of high-resolution simulations for tropical cyclone and extreme weather studies.