Aug 05, 2022

After Extended Dry Weather, Rainfall Forecasted to Return to Brazil

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

After a prolonged period of dry weather in central and southern Brazil caused by a blocking high pressure system, the forecast is calling for changes starting as soon as this weekend. States in central Brazil such as Mato Grosso and Goias have not received a significant rainfall in more than three months, while areas of southern Brazil have been dry for about 30 days.

The high pressure ridge has prevented cold fronts from moving into southern Brazil and progressing northward to central Brazil, but the various weather models are now forecasting that the ridge is starting to weaken.

The models are not in complete agreement, but the states in southern Brazil may receive 20-40 mm of rainfall next week (0.8 -1.6 inches) or maybe even as high as 50-70 mm (2 to 3 inches). Rainfall amounts will diminish as the front moves north with Mato Grosso and Goias forecasted to receive approximately 10 mm (0.4 inches). Coverage of these first rains can be very irregular and generalized rains in central Brazil usually do not occur until late September or October.

Any rainfall would be important to help recharge the soil moisture ahead of planting the 2022/23 crops. The first crop to be planted will be the full-season corn in southern Brazil. Farmers are allowed to start planting their corn as soon as the weather permits. Generally, the first corn is planted by the end of August with September being the main planting month.

Brazilian farmers are allowed to start planting their soybeans after the "Soybean Free" period ends. In the state of Parana, the "Soybean Free" period will end on September 10th and in Mato Grosso, it ends on September 15th. The "Soybean Free" period ends a little later in other states depending on location. There are no live soybean plants permitted during the "Soybean Free" period was a way to slow the spread of soybean rust from one growing season to the next.

The main crop growing right now in Brazil is the winter wheat in southern Brazil. Brazil's three southernmost states of Parana, Santa Catarina, and Rio Grande do Sul account for approximately 90% of Brazil's wheat production.