Extratropical Cyclone and Cold Front Trigger Severe Storms Across Brazil’s Centre‑South

Overview

• Storms intensified on Wednesday, Sept. 30, with the strongest activity focused in Santa Catarina and Paraná and spreading into Mato Grosso do Sul, São Paulo, Minas Gerais and Rio de Janeiro.
• National and state agencies including Inmet and multiple Defesa Civils have issued yellow, orange and red alerts covering dozens to hundreds of municipalities and are sending Cell Broadcast and SMS warnings to residents.
• Forecasts call for heavy rainfall rates (tens of millimeters per hour and spots of 30–100 mm per day), gusts up to about 100 km/h, hail and localized tornado risk especially in Paraná.
• The cold front will drive a marked temperature drop first over the South and then into the Southeast across the next two to three days while other areas remain under strong heat warnings tied to El Niño.
• Authorities warn of likely impacts on people and infrastructure including urban flooding, landslides on vulnerable slopes, fallen trees, power outages and mixed agricultural effects depending on timing of harvests.