South America Calling

Another week has gone by and the weather situation has not improved for very many areas of South America. What was a very dry winter has turned into a dry spring for the vast majority of the continent. Though fronts have been consistent and frequent, which both Argentina and southern Brazil rely upon for winter and spring precipitation gains, the actual amounts produced from these fronts have been limited. Pockets in eastern Argentina, but mostly in the state of Buenos Aires, southeastern Paraguay, Uruguay, and the state of Rio Grande do Sul in far southern Brazil have been beneficiaries of these fronts. Soil moisture in these areas is adequate for planting corn or soybeans where appropriate, and growth and development of winter wheat and other small grains.

But outside of these small areas, which may account for as little as 15% of the total production areas of the primary growing corridor in these countries, soil moisture is lacking. Western and northern Argentina have seen some showers move through at times, but they have generally been scattered and light. Soil moisture is generally below normal in these states and, when combined with frequently cold temperatures, corn planting has been slow. The Buenos Aires Grain Exchange notes on X that most of all the center and western portions of the country's growing regions are in drought. https://x.com/…. They also note the moisture situation is much worse than last year, and more reminiscent of 2022, when historic drought gripped the country later in the season. https://x.com/….

In the case of south-central Brazil, the soil moisture situation is even more dire. Some areas in Parana, Sao Paulo, and Mato Grosso do Sul have not seen a drop of rain in almost four months when they regularly see scattered showers in late winter and early spring. Those have just not been very numerous this year. Farther north in central Brazil, the dry season has been especially rough in states like Mato Grosso, Goias, and Minas Gerais, which account for roughly 40% of soybean and almost half of corn production in Brazil. Though it is typical for these states to not see any rain for months at a time, which has been the case this year, temperatures have been routinely well above normal. Temperatures over 40 degrees Celsius (104 degrees Fahrenheit) have been more common this winter and early spring, which has exacerbated the lack of soil moisture. These areas are essentially barren, waiting for the wet season rains to come.

Some of these dry areas are getting rain. A front in southern Brazil has brought more good moisture to southeastern Paraguay and the state of Rio Grande do Sul already. That front will lift northward with potential for more than 50 millimeters (about 2 inches) in the state of Parana this weekend. Nearby areas of southern Mato Grosso do Sul and Sao Paulo will also see some rain out of this as well. Additional showers will likely move through these same areas in the middle of next week, though with much lower coverage and amounts. But many of these areas have soil moisture deficits of 150 millimeters (about 6 inches) or more; 50 millimeters may cut into that, but it would certainly not eliminate the ongoing drought.

A front moving through Argentina late next week and into southern Brazil for the weekend could also produce some showers. But this looks like another case of the rich getting richer, with Buenos Aires, eastern Paraguay, Uruguay, and Rio Grande do Sul getting all the benefit, while western Argentina and south-central Brazil see little or none.

At least for these areas, the fronts look to remain frequent through these regions. What does not look likely is for them to move far enough north into central Brazil to moisten soils before the primary wet season showers begin. They typically start to develop the last few days of September and slowly fill in during the month of October, becoming daily from November through March before they start to wind down again. The end of the latest American GFS models have these rains starting to move in on time on Sept. 26-27. However, with how dry soils currently are, and the lack of rain coming before these wet season rains begin, it may take a long time for producers to begin to think about planting their first crop of soybeans, perhaps deeper into October than they normally would. If they do see delays, that would set off concerns for their second-season (safrinha) corn and cotton crops.

To find more international weather conditions and your local forecast from DTN, visit https://www.dtnpf.com/….

John Baranick can be reached at john.baranick@dtn.com

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