Brazil’s National Institute of Meteorology (Inmet) has issued a significant danger alert for extreme rainfall projected to impact large swaths of Minas Gerais, Rio de Janeiro, and São Paulo. The critical weather warning, which commenced at 12:00 PM on Thursday, February 6, 2025, is slated to remain in effect until 11:59 PM on Saturday, February 8, 2025, encompassing a period of heightened vigilance for millions across the Southeast region.
Forecasts indicate precipitation volumes could exceed 60 millimeters per hour or accumulate over 100 millimeters within a single day. These levels are categorized by meteorological authorities as extremely high, carrying substantial potential for widespread flooding, dangerous river overflows, and devastating landslides, which pose direct threats to infrastructure and public safety.
The severity of the forecasted conditions has prompted the activation of the Committee of Extreme Events, an interagency body now closely monitoring meteorological developments across the affected states. This proactive measure aims to coordinate response efforts and ensure timely assistance to areas most at risk from the incoming weather system.
Region-Wide Impact and Affected Municipalities
The alert encompasses a broad geographical area, targeting several key regions known for their vulnerability to heavy rains. In Minas Gerais, the warning applies to the Southern and Southwestern regions, as well as the Zona da Mata Mineira. Rio de Janeiro faces a comprehensive alert, including its Southern Fluminense, Baixadas, Central Fluminense, the sprawling Greater Rio Metropolitan Area, and the Northern Fluminense.
Meanwhile, in São Paulo, residents of the Vale do Paraíba Paulista are urged to prepare for adverse conditions. These geographical zones include urban centers, mountainous terrains, and coastal areas, each presenting unique challenges for managing the impact of intense rainfall. The diverse topography means a wide range of potential hazards from flash floods to mudslides.
A total of 160 municipalities are currently under this high-danger alert, highlighting the extensive nature of the weather event. Among the named cities are prominent tourist destinations and densely populated areas, including Campos do Jordão (SP), Taubaté (SP), Angra dos Reis (RJ), Cabo Frio (RJ), Belford Roxo (RJ), Paraty (RJ), Niterói (RJ), Juiz de Fora (MG), Santa Bárbara do Monte Verde (MG), and Rochedo de Minas (MG).
Authorities are stressing the importance of community preparedness and local government readiness to respond effectively to emergencies that may arise during this period. The scope of the alert necessitates broad communication and coordination to mitigate potential harm and ensure public safety throughout the affected regions.
Safety Guidelines for Residents
Inmet has issued crucial guidelines to help residents navigate the impending severe weather safely. These recommendations are designed to minimize risks associated with flooding, electrical hazards, and geological instabilities that often accompany heavy rainfall.
The institute advises the population to take immediate precautions:
- Disconnect electrical appliances from power sources, especially during periods of intense rain or if water begins to rise.
- Carefully observe any signs of alteration in slopes and terrains, such as cracks in the ground, leaning trees, or changes in water flow, which could indicate an increased risk of landslides.
- Remain in a sheltered location during periods of intense rain, avoiding unnecessary travel or exposure to open areas.
- In any situation of imminent danger or emergency, promptly contact the Civil Defense (Defesa Civil) at 199.
Adherence to these safety measures is paramount for safeguarding lives and property, as rapid onset events like flash floods and landslides can develop with little warning. Residents are encouraged to prepare emergency kits and stay informed through official channels.
Meteorological Context: The ZCAS Influence
Meteorologists from Climatempo have identified this episode of severe weather as a direct consequence of the South Atlantic Convergence Zone (ZCAS), a persistent weather pattern known for bringing heavy and continuous rainfall to parts of Brazil. The ZCAS is expected to solidify its presence over the region for the coming days, prolonging the period of instability and high precipitation.
The establishment of the ZCAS is a critical factor driving the intensity and duration of the current rainfall alert. This atmospheric phenomenon typically creates a band of cloudiness and rain that extends from the Amazon basin into the South Atlantic, drawing moisture and concentrating it over the southeastern states. Its influence makes prolonged periods of significant rainfall more likely.
Understanding the underlying meteorological dynamics helps authorities and residents anticipate the nature of the threat. The ZCAS often leads to saturated soils, increasing the risk of landslides even after the initial heavy downpours have passed, as water continues to permeate the ground and destabilize slopes.
Weekend Forecast for Key Cities (February 8, 2025)
Detailed forecasts for Saturday, February 8, 2025, provided by Climatempo, underscore the high probability of rain across the threatened areas. Temperatures will vary, but humidity levels are expected to remain high, exacerbating the feeling of moisture and increasing the potential for cloud cover.
Key city forecasts include:
- São Paulo (capital): Minimum 19°C, Maximum 32°C; Humidity 55% to 100%; 88% chance of rain.
- Campos do Jordão (SP): Minimum 17°C, Maximum 21°C; Humidity 81% to 95%; 99% chance of rain.
- Taubaté (SP): Minimum 20°C, Maximum 29°C; Humidity 66% to 100%; 99% chance of rain.
- Rio de Janeiro (capital): Minimum 23°C, Maximum 34°C; Humidity 69% to 96%; 94% chance of rain.
- Angra dos Reis (RJ): Minimum 23°C, Maximum 28°C; Humidity 76% to 98%; 99% chance of rain.
- Cabo Frio (RJ): Minimum 24°C, Maximum 28°C; Humidity 80% to 97%; 97% chance of rain.
- Belford Roxo (RJ): Minimum 23°C, Maximum 30°C; Humidity 71% to 97%; 94% chance of rain.
- Paraty (RJ): Minimum 22°C, Maximum 27°C; Humidity 76% to 96%; 92% chance of rain.
- Niterói (RJ): Minimum 24°C, Maximum 29°C; Humidity 73% to 97%; 89% chance of rain.
- Juiz de Fora (MG): Minimum 20°C, Maximum 27°C; Humidity 73% to 100%; 96% chance of rain.
- Santa Bárbara do Monte Verde (MG): Minimum 19°C, Maximum 28°C; Humidity 68% to 100%; 94% chance of rain.
- Rochedo de Minas (MG): Minimum 21°C, Maximum 27°C; Humidity 79% to 100%; 100% chance of rain.
These detailed city-specific predictions offer residents and local authorities vital information for proactive planning and response. High chances of rain, coupled with elevated humidity, underscore the need for continuous monitoring and adherence to safety protocols through the weekend.
