A collection of 10 high-impact extreme precipitation events occurring in Southeastern South America during the warm season has been analyzed using statistical (ESD) and dynamical downscaling approaches. Regional Climate Models from the CORDEX database for the South American domain at two horizontal resolutions, 50 km and 25 km, short-term simulations at 20 km and at 4 km convective-permitting resolution and statistical downscaling techniques based on the analogue method and the generalized linear model approach were evaluated. The analysis includes observational datasets based on gridded data, station data and satellite products that allow assessing the observational uncertainty that characterizes extreme events in the region. It is found that the ability of the modelling strategies in capturing the main features of the extreme rainfall varies across the events. The higher the horizontal resolution of the models, the more intense and localized the core of the rainfall event, being the location of the exit region of the low-level jet and the low-level moisture flux convergence during the initial stages of the events the most relevant features that determine models’ ability of capturing the location and intensity of the core of the heavy rainfall. ESD models based on the generalized linear approach overestimate the spatial extension of the events and underestimate the intensity of the local maxima. Weather-like convective-permitting simulations depict an overall good performance in reproducing both the rainfall patterns and the triggering mechanisms of the extreme events as expected, given that these simulations are strongly controlled by the initial conditions.

已使用统计（ESD）和动态降尺度方法分析了南美洲东南部在暖季期间发生的10个高影响力极端降水事件的集合。来自CORDEX数据库的南美地区区域气候模型，两个水平分辨率分别为50 km和25 km，短期模拟为20 km和4 km，对流许可分辨率和基于模拟方法和广义化的统计缩减技术评估了线性模型方法。分析包括基于栅格数据，台站数据和卫星产品的观测数据集，这些数据集可以评估表征该地区极端事件的观测不确定性。结果发现，建模策略捕获极端降雨的主要特征的能力随事件的发生而变化。模型的水平分辨率越高，降雨事件的核心就越集中和集中，即在事件的初始阶段低空急流出口区域的位置和低空水汽通量的收敛。决定模型捕获强降雨核心位置和强度的能力的最相关特征。基于广义线性方法的ESD模型高估了事件的空间扩展，而低估了局部最大值的强度。