Evaluation of North Atlantic Tropical Cyclones in a Convection-Permitting Regional Climate Simulation

Abstract. This study employs a 20-year, convection-permitting (CP) regional climate model, forced by ERA5 reanalysis, to assess the representation and climatology of tropical cyclones (TCs) over the North Atlantic. We demonstrate that, relative to observations from Hurricane Database version 2 (HURDAT2), the model better captures TC frequency, averaging 12.25 TCs a year compared to 12.5 in HURDAT2 and 7.45 in ERA5. The model also successfully resolves the upper tail of the observed TC intensity distribution, while ERA5 only resolves TCs of Category 2 or lower intensity on the Saffir-Simpson scale. By contrast, the model and ERA5 show comparable skill at resolving the overall distribution of TC central pressure, implying that minimum central pressure may be a skillful predictor of TC intensity for coarser datasets. Spatially, the CP model exhibits particular added value over data-sparse coastlines in Central America and the Caribbean, successfully resolving clusters of TC track density that are missing in ERA5. Finally, a composite analysis of the 10 strongest TCs in each dataset, along with a case study of Hurricane Isabel (2003), reveals that TCs in the CP model have realistic structural features of the TC inner core that are not apparent in ERA5, including a more compact and intense radius of maximum wind. This is likely due to the CP model’s enhanced capability to capture small-scale convection and storm structure. These improvements exemplify the represented CP model’s efficacy for TC-induced local-scale hazard preparedness, and risk assessment of critical infrastructure, especially in regions lacking existing high resolution climate data.