20 Years of MCSs simulations over South America using a convection-permitting model

Mesoscale convective systems (MCSs) are complex meteorological phenomena that significantly influence precipitation and weather patterns globally. While extensive research on MCSs has been conducted in various parts of the world, South America, home to some of the most intense MCSs and storms, remains a relatively understudied region. This study addresses this knowledge gap by investigating observed MCSs and their representation in a 20-year 4 km grid spacing simulation using the Weather Research and Forecasting model across different subregions of South America. MCS characteristics, such as size, duration, and maximum precipitation, are found to be well-represented by the model, although there is a tendency to overestimate maximum precipitation. Additionally, this research explores the impact of the El Niño Southern Oscillation (ENSO) on MCS occurrence in South America. The Southeast South America tends to experience more MCS occurrences during El Niño events, while the North–South America exhibits the opposite pattern. However, the study also reveals nuanced deviations from expected correlations during specific ENSO events, highlighting the complex relationship between ENSO and MCS behavior. These findings contribute to advancing our comprehension of mesoscale convective processes in South America and set the stage for further investigations that will focus on climate change impacts on the region.