September arrives with rain and cold weather in the South-Central region.

The arrival of September should change the weather pattern in the South-Central region of Brazil, with increased rainfall and temperatures near or below average. According to data released by Meteored, the change should occur between the end of August and the beginning of the meteorological spring, on September 1st, with the advance of cold fronts over areas of the South, Southeast, and Midwest.

The forecast represents a change from the last week of August, which was marked by above-average temperatures across much of the country. For the first week of September, the ECMWF model indicates atmospheric circulation more favorable to the entry of frontal systems in the South-Central region.

Rain is expected to move into inland areas.

According to data released by Meteored, the positive precipitation anomalies, which this week are more concentrated over Rio Grande do Sul and areas of the extreme south of the continent, should shift to lower latitudes between August 31 and September 7.

The trend indicates increased rainfall over Paraná, São Paulo, Mato Grosso do Sul, and parts of the Southeast region. This change may benefit regions still experiencing the dry season. In the North of the country, however, the forecast is different. Rainfall is expected to remain below average, maintaining the water deficit scenario observed in the northern half of the region.

Temperatures are expected to drop in the South-Central region.

The change is also reflected in temperature projections. According to data released by Meteored, the above-average heat prevalent in much of Brazil this week is losing strength in the South-Central region.

The forecast indicates temperatures near or below average in the South, Southeast, and Midwest. The largest negative anomalies are expected to range between 1°C and 3°C below average. In the northern half of the country, the heat should continue to predominate. Temperatures remain above average, although the area with anomalies of 3°C to 6°C above average should decrease slightly and become more concentrated over the Northeast.

A cold front could change the landscape in early September.

According to data released by Meteored, the predicted scenario indicates atmospheric circulation more favorable to the advance of cold fronts through the Central-South region at the beginning of the meteorological spring. This increases the possibility of more widespread cold air incursions than those recorded during the second half of August. At the same time, the potential for rain in inland areas of the country increases.

A cold front is expected to move through the South from Thursday (27). The system should be active during the weekend and leave conditions for heavy rains, with a risk of disruption.

 Between Monday (31) and Tuesday (1st), the system should advance over areas of the Southeast and Midwest. The passage should favor the formation of areas of instability and episodes of rain in regions that are still in the dry season period.

Spring weather begins with a change in pattern.

Meteorological spring begins on September 1st and, being a transitional season, can exhibit characteristics of both winter and summer throughout the quarter.

According to data released by Meteored, the first week of the new season should show different behavior than that observed in the final stretch of August, with a less hot pattern and more favorable conditions for rainfall in parts of the South-Central region.

Despite the indications, the forecast may still be subject to adjustments. The models indicate a consistent trend across different runs, but there are still several days left until the projected period. Therefore, future updates should be monitored to verify the evolution of the cold front, rainfall amounts, and temperatures predicted for the beginning of September.