Inmet: weather forecast between December 02nd and 09th, 2024

Figure 1 shows the forecast of accumulated rainfall, according to the Cosmo numerical model of the National Institute of Meteorology (Inmet), indicating that volumes may exceed 50 mm in much of the country (represented in shades of yellow), except in the north of the North Region and in the east and north of the Northeast, where rainfall is expected to be below 20 mm.

Forecast for December 02-09, 2024

Na Northern Region, areas of instability associated with heat and high humidity will cause rain showers throughout the week, with accumulations above 30 mm (green tones) in much of the region. Rainfall may exceed 100 mm in some places (red to pink tones) in Amazonas, eastern Acre, southern Pará, Rondônia and eastern Tocantins. The action of the Intertropical Convergence Zone (ITCZ) is expected to cause accumulations above 80 mm in northern Amapá. However, in northern Pará and much of Roraima, rainfall accumulations are expected to be below 20 mm.

Na North East Region, the action of an Upper Level Cyclonic Vortex (VCAN) over the region could cause rain showers as the system moves inland throughout the week, mainly in areas of western Bahia, southern Maranhão and areas of Piauí, with the possibility of accumulations above 20 mm. However, in the central-eastern part of Bahia, the hinterlands of Pernambuco and Alagoas, as well as southeastern Piauí, the weather should remain hot and with a low probability of rain.

Na Midwest region, instabilities will persist, providing locally significant rainfall in Mato Grosso do Sul, Mato Grosso and much of Goiás, with expected accumulations above 40 mm, potentially reaching 100 mm in some locations (red tones). In the southwest of Mato Grosso do Sul and southwest of Goiás, volumes are expected to be below 40 mm in the coming days.

Na Southeast, much of the region will experience heavy rainfall in the coming days, due to the instability caused by the approach of a frontal system in the ocean. The highest accumulations over the week are forecast for São Paulo, south-central Minas Gerais and Rio de Janeiro, with volumes above 50 mm, and possibly exceeding 100 mm in some locations. The trend is for reduced rainfall from December 6th in Minas Gerais, Espírito Santo and Rio de Janeiro.

Na South, the week will begin with instability throughout the region, due to the passage of a frontal system that could cause storms, with accumulations above 50 mm. The displacement of the frontal system will reduce rainfall in Rio Grande do Sul, however, from December 6th, a new instability will act, allowing heavy rains in the following days. Accumulations above 100 mm are forecast for the north of Rio Grande do Sul, west of Santa Catarina and Paraná.