Inmet presents forecast for August, September and October 2023

The National Institute of Meteorology (Inmet) released its agroclimatic forecast for August, September and October 2023. The data considers that El Niño conditions will remain during the end of this winter, with chances of lasting until spring (probability greater than 90 %). The phenomenon is expected to vary in intensity from moderate to strong. (Analysis of El Niño and plagues can be seen in the video with agronomist Suellen Drumond.)

Northern Region

The climate forecast produced with the objective method (multimodel – cooperation between Inpe, Inmet and Funceme) indicates a predominance of rainfall below the climatological average in a large part of the region (Figure 5a), possibly associated with the impacts that El Niño can cause. However, in the months of August and September, the rains should be located further to the northwest of Amazonas and Roraima.

The average air temperature is expected to prevail above the climatology in practically the entire region, mainly in the southeast of Pará and Tocantins (Figure 5b). It should be noted that the lack of rain in the south of the Amazon is very common between the months of August and September and, combined with the forecast of high temperatures and low relative humidity, can favor the incidence of fires and forest fires.

The water balance forecast for the coming months indicates that the highest levels of water in the soil will remain in the extreme northwest of the region, mainly in areas of northwestern Amazonas and western Roraima, with values ​​above 70% (Figures 6a, 6b and 6c). In other areas, low storage levels are expected, reaching values ​​below 10%, mainly in the months of September and October (Figures 6a, 6b and 6c).

North East Region

Just like the North Region, the forecast indicates below-average rainfall throughout the Northeast Region, but mainly in the west of Bahia, south of Maranhão and Piauí, due to the impacts that the El Niño phenomenon can cause (Figure 5a).

As for air temperature, it must be above the historical average throughout the region (Figure 5b).

The predicted reduction in rainfall in the coming months could negatively affect water levels in the soil in all months, reaching values ​​below 10%, impacting crops that are in more sensitive phenological stages, but could favor crops that are found during maturation and harvest (Figures 6a, 6b and 6c). In areas on the east coast of the region, including areas of SEALBA (an area that covers the states of Sergipe, Alagoas and northeastern Bahia), the forecast indicates a reduction in soil moisture, mainly in the months of September and October, with values ​​below 50%, which will also impact third-crop crops that are at more sensitive phenological stages or under water restrictions (Figures 6a, 6b and 6c).

Midwest region

The multimodel forecast indicates a precipitation trend below the historical average (Figure 5a) with a tendency for relative air humidity to decrease in the coming months, very common during the region's dry period. However, there is the possibility of rain from October onwards over the south of Mato Grosso do Sul.

Forecasts indicate that temperatures should be above climatology in the coming months (Figure 5b), due to the persistence of dry and hot air masses, which increases the probability of fires during this period.

Regarding water availability in the soil, the model continues to indicate a reduction in water storage, reaching values ​​below 10% throughout the quarter, due to the decrease in rainfall, which is characteristic of the region. This condition may affect second-crop and winter agricultural crops that are at sensitive phenological stages or under water deficiency, mainly in areas of Goiás and Mato Grosso, but will benefit crops in maturation and harvest (Figures 6a, 6b and 6c). However, in areas in the center-south of Mato Grosso do Sul, the gradual return of rain may favor the maintenance of water levels in the soil, especially from October onwards (Figures 6a, 6b and 6c).

Southeast

Rainfall below the historical average is forecast in practically the entire region (Figure 5a), except in the center and south of São Paulo, where precipitation is expected to be close to and slightly above average.

As in the Central-West Region, the air temperature must be above the historical average (Figure 5b), and combined with the reduction in relative air humidity, the probability of fires in the coming months increases.

The water balance forecast for the region indicates soil water storage values ​​of less than 10% in practically the entire quarter, mainly in areas in the center and north of Minas Gerais, in Espírito Santo and northwest of São Paulo, which will favor the maturation and harvesting operations of second-crop and winter crops (Figures 6a, 6b and 6c). In areas in the south of São Paulo, in addition to the extreme south of Minas Gerais and Rio de Janeiro, rains caused by the passage of cold fronts may favor the maintenance of water levels in the soil, especially in the months of September and October (Figures 6a, 6b and 6c).

South

The forecast indicates the predominance of rainfall above the climatological average in almost the entire region (Figure 5a), due to the presence of more stationary cold fronts, as a result of the impacts that El Niño can cause. In the northwest of Paraná, precipitation is expected to be close to the climatological average.

The air temperature is expected to prevail above the historical average throughout the region, but mainly in the north and west of Paraná (Figure 5b). However, possible incursions of air masses of polar origin cannot be ruled out, which could cause a decline in temperatures and occasional frosts, especially in mountainous areas.

The predicted rainfall volumes will favor water levels in the soil, with values ​​exceeding 90%, even generating a water surplus, mainly in the months of September and October. This condition may impact second-crop and winter crops that are maturing and harvesting, but will favor crops in reproductive development (Figures 6a, 6b and 6c).