The role of convection-permitting RegCM5 simulations in representing synoptic-scale cyclones over Southeastern South America

Southeastern South America (SESA) stands out as a hotspot on the planet where weather and climate extremes occur with notable frequency, exerting negative impacts on various socio-economic activities. One cause of these extremes are the synoptic-scale cyclones. In this sense, the objective of this study is to evaluate the performance of a convection-permitting scale simulation (CP) with Regional Climate Model version 5 (RegCM5) in simulating the cyclone features (frequency, intensity, lifetime, preferential regions, precipitation, etc.) in the SESA region from January 2018 to December 2021. The CP simulation was driven by ERA5 reanalysis with 3.0 km of horizontal grid spacing in a domain covering from ~ 11°S to 35°S. Cyclones are identified with a tracking algorithm based on relative vorticity at 925 hPa. The cyclone features in the CP simulation are compared with that from ERA5. The mesoscale structure of the simulated precipitation associated with cyclones is compared with satellite estimates. Overall, CP simulation captured the main observed features associated with cyclones.