With a Prevots risk level of 3, an "enhanced" risk according to Mateusz Taszarek's AI-based website and the GEFS model, and a SALLJ (South American Low Level Jet) of around 75 km/h (40 kt) in the region at 850 hPa:
A severe weather system swept through Argentina, Uruguay, and Brazil on Tuesday 07/28, bringing destructive winds and, above all, gorilla hail.
But by far, the highlight of the day was this clokcwise spin, photogenic and likely violent tornado near the towns of Senador Salgado Filho and Sete de Setembro, in the state of Rio Grande do Sul, Brazil...
It formed from an equally photogenic Left-Mover LP-Supercell that developed over Argentina and quickly expanded and crossed the border into Brazil, where a nudger cell formed and merged with it along its northwest flank.
This resulted in a possible violent tornado tornado that received a preliminary F3 rating from Metsul (the main agency responsible for agro-meteorological forecasts
in the Brazilian state where the tornado occurred), with winds of at least 300 km/h (187 mph); however, Metsul experts themselves clarified that it could also be classified as an F4 once they conduct a more in-depth analysis of the damage:
MetSul Meteorologia classifica preliminarmente o tornado no Noroeste gaúcho com F3 com vento estimado em até 300 km/h.
t.co
Meanwhile, the Prevots are already hard at work investigating and assessing the damage in the area, and their preliminary classification is high-end F3 based solely on an analysis of just 4 of the 81 total damage markers they have been able to collect.
This is already the second potential tornado ≥F4 so far this year in the SESA (Southeastern South America) region amid the super El Niño we are currently experiencing, demonstrating once again that, proportionally speaking, the SESA region is undoubtedly the region most favored (or rather, most disadvantaged) in terms of severe weather and tornado events worldwide.
This is just the beginning, we only have to wait for spring (Southern Hemisphere spring), when the South American corridor is climatologically more active, especially in the context of a super El Niño: