Heavy Rainfall and Convective Weather Expected in Central and Southeastern Brazil

Affected by a low-pressure trough between two subtropical high-pressure systems (Figure 1), moderate to heavy rain, with localized downpours, is expected in central and southeastern Brazil, as well as northern Bolivia from January 3 to 6, 2026 (BJT). The areas most likely to experience intense rainfall include the Brazilian states of Mato Grosso, Goiás, the Federal District, Minas Gerais, Espírito Santo, and Rio de Janeiro, as well as the Bolivian departments of Beni and Pando. Accumulated rainfall during this period is forecasted to be between 40 and 80 mm, with localized areas potentially reaching 120 to 150 mm (Figure 2). These conditions may be accompanied by short-duration heavy rain, thunderstorms, and strong winds (Figure 3). Precautions are advised against potential secondary disasters such as flooding, landslides, mudslides, and urban waterlogging in the aforementioned regions, as well as adverse impacts on power infrastructure, transportation, and other sectors.

Figure 1  Forecast of 500 hPa Geopotential Height (units: dagpm) and 850 hPa Wind Field at 08:00on January 4, 2026 (BJT) (units: m/s)

Figure 2 Accumulated Precipitation from 08:00 on January 3 to 08:00 on January 7, 2026 (BJT) (Unit: mm)

Figure 3  Forecast of 850 hPa Wind Field (wind barbs, unit: m/s) and K-Index (shaded, unit: °C) at 02:00 (BJT) on January 4, 2026

           Author: Xie Jin                        Reviewer: Bao Yuanyuan

English reviewer:Wang Yi                                                                       Issue approver:Dai Kan