Mesoscale Convective Systems and Their Atmospheric Drivers Over South America

Understanding the atmospheric conditions that favor the development of Mesoscale Convective Systems (MCSs) is critical for improving convection-permitting models, particularly in regions with sparse observational data. This study investigates the environmental drivers of MCSs over South America using 20 years of simulations from the Weather Research and Forecasting (WRF) model version 4.1.5. These simulations, conducted within the South America Affinity Group (NSF NCAR), provide high spatial and temporal resolution, downscaling three-hourly ERA5 reanalysis data to produce 4 km and hourly outputs. By focusing on the atmospheric conditions, we aim to identify the key factors that promote MCS formation in South America. We specifically examine the role of cold pools in MCSs, investigating how they interact with surface temperature, precipitation, Convective Available Potential Energy (CAPE), Convective Inhibition (CIN), equivalent potential temperature (θe), and wind shear at varying altitudes above the surface. The results are presented for five South American regions (NWS, NSA, SAM, NES, SES) and analyzed by season, revealing significant spatial and temporal variability. This work contributes to our understanding of convection organization in the region and offers insights into improving the representation of MCSs in weather prediction models. The findings also provide valuable information to help fill observational gaps, particularly in remote or data-scarce areas of South America.