Observed mesoscale convective systems over South America (2001-2021)

Observed Mesoscale Convective Systems (MCSs) over South America (2001-2020) This dataset was developed and used by Rehbein et al. (2025). Please review this paper for a complete description of this dataset. The MCSs in this dataset were first identified and tracked using brightness temperature (Tb) from geostationary infrared satellite imagery (MERGIR product; Janowiak et al., 2004). For each timestep of all objects tracked with Tb, the precipitation (IMERG; Huffman et al., 2019) underneath the cloud shield was calculated. Then, the family of objects that had met the criteria for an MCS (as described below) was selected. MCSs were obtained through the identification and tracking of all cloud systems over South America using the Forecasting and Tracking the evolution of Cloud Clusters (ForTraCC*; Machado et al., 1998; Vila et al., 2008). ForTraCC was set to identify and track all the objects with one or more contiguous pixels with brightness temperature equal to or above 241 K. Since ForTraCC tracked and stored all pixel families that match that criteria, a post‐processing program was used to select the MCSs in that huge dataset (see https://github.com/salvatirehbein/percolator). The final MCSs have, therefore, in common the following characteristics (Prein et al., 2024): 1. The continuous Tb ≤ 241 K area must be at least 40,000 km2 for at least four continuous hours.2. The maximum hourly precipitation underneath the ≤241 K Tb area must be larger than 10 mm hr^-1 for at least 4 continuous hours.3. The hourly precipitation volume must exceed 20,000 km2 mm h^-1 (e.g., 100 km × 100 km × 2 mm h^-1) at least once in the lifetime of the MCS.4. The minimum Tb must be <225 K during the MCS lifetime to account for overshooting tops. _______________________________________________________________________ *Besides its immense contribution to research, ForTraCC is also used operationally at the Brazilian Center for Forecast and Climate Studies of the National Institute of Spatial Research (CPTEC/INPE; http://pindara.cptec.inpe.br/fortracc/) for nowcasting. _______________________________________________________________________ References Machado, L. A. T., Rossow, W. B., Guedes, R. L., & Walker, A. W. (1998). Life cycle variations of mesoscale convective systems over the Americas. Monthly Weather Review, 126(6), 1630-1654. Prein, A. F., Feng, Z., Moon, Z., Ocasio, K. M. N., Kukulies, J., Roca, R., ... & Rasmussen, R. (2023). Km-scale simulations of mesoscale convective systems (MCSs) over South America-A feature tracker intercomparison. Authorea Preprints. Rehbein, A., Prein, A. F., Ambrizzi, T., Ikeda, K., Liu, C., & Rasmussen, R. M. (2025). 20 Years of MCSs simulations over South America using a convection-permitting model. Climate Dynamics, 63(1), 38. Vila, D. A., Machado, L. A. T., Laurent, H., & Velasco, I. (2008). Forecast and Tracking the Evolution of Cloud Clusters (ForTraCC) using satellite infrared imagery: Methodology and validation. Weather and Forecasting, 23(2), 233-245.