Polar Air Drives Frost in the South as a Coastal Front Keeps Rain Over the Southeast

Overview

• - A polar air mass over southern Brazil on Wednesday is producing widespread frost in Rio Grande do Sul and Santa Catarina while a coastal front keeps skies cloudy and wet in São Paulo and Rio de Janeiro.
• - Inmet alerts call for heavy rain of 20–30 mm per hour, up to 50 mm per day, wind gusts near 60 km/h and isolated hail across parts of São Paulo, Rio, Minas, Paraná, Mato Grosso do Sul and Piauí through Thursday.
• - São Paulo logged its coldest afternoon of the year on Tuesday, with a high of 18.3°C, and forecasts point to a cool, gray stretch with light showers this week and a higher chance of heavier rain on Saturday.
• - The Intertropical Convergence Zone, a belt of rising air near the equator, is fueling frequent downpours and storm risk in the North, especially Amapá, Pará, Amazonas and Roraima, with spotty showers on parts of the Northeast coast.
• - Frost warnings raise crop damage concerns in the South, while urban areas under the rain alerts face a risk of street flooding, fallen trees and power outages, and officials urge residents to follow Civil Defense guidance.