Future Changes in the ENSO –Tropical Cyclone Teleconnection and Extreme Atlantic Hurricane Seasons

Tropical cyclone (TC) risk depends on multiple factors, including the severity of TC hazards and the probability of TC occurrence. Although future changes in TC occurrence remain uncertain, substantial advances have been made in projecting future changes in the severity of TC hazards, including associated wind and precipitation. These advances have been enabled in part by considering how historically-impactful TC events could change if similar events were to happen in a future warmer climate. Here, we applied this “storyline” approach using ensembles of convection-permitting (3.5km resolution) regional model simulations. First, the historically-impactful TC events were hindcasted under the actual synoptic conditions and climate state in which they occurred. After verifying that the hindcast quality is reasonable, we then performed experiments representing the TC events if they were to occur in the future, by retaining the original synoptic conditions but perturbing the climate state to represent a future warmer climate. We investigated how 33 Atlantic TCs that produced substantial impacts could change in the future. In addition, we investigated how future projections of TC characteristics could be sensitive to the treatment of the ocean (i.e., using prescribed sea-surface temperatures compared to atmosphere-ocean coupling). This research aims to provide information on how TCs in a changing climate could impact coastal and island communities in the future, by focusing on events for which there is a historical context.