South America Calling

Argentina had been in the midst of a massive drought to start off its 2024-25 growing season; some areas had not seen rain in months in western portions of the country. However, a storm system that started the wet season showers in central Brazil two weeks ago, first moved through Argentina and southern Brazil, setting off a string of very frequent storm systems that were more generous with rainfall.

During the past two weeks, DTN estimates that the largest drought areas in the western end of Argentina -- including the state of Cordoba, a major production area -- have received more than 75 millimeters (about 3 inches) of rainfall while some spots picked up more than 150 mm (about 6 inches). Rainfall has not been as widespread or beneficial in the far southern or eastern portions of the country, with some areas completely missing out, though some of these areas also had more soil moisture and better conditions for growth prior to the last two weeks.

Southern Brazil, which did not have the same dryness issues as western Argentina, also benefited from widespread rainfall. From the state of Rio Grande do Sul to Parana, a general 50-100 mm (about 2-4 inches) has fallen during the last two weeks, providing producers with enough moisture to continue planting corn and soybeans at a good pace, and for early growing conditions to be quite good as well.

After a system concluded Oct. 24, the region is going through a drier stretch though. The train of storms that had been in place finally found its caboose and the weather pattern is going quieter. Outside of a couple disturbances, virtually no rain is forecast to fall in either region through Nov. 1.

A break in the rain may be what producers need to continue with their planting, or for winter crop harvest. The break in good weather is probably not a concern in the short term. Topsoil moisture is much improved and early growing plants can probably take a week off without rainfall.

Drought still remains in some areas though and that could be exacerbated by rising temperatures next week. Highs in the 30s Celsius (upper 80s to upper 90s Fahrenheit) could cause stress to young plants where soil moisture is not as available.

It is not a deep concern as long as the forecast pans out. Mid-to-long range forecasts start to bring showers back into the Andes Mountains Nov. 1 and spread showers with systems moving through both Argentina and southern Brazil in early November as the storm train builds back up.

If models are wrong, however, the dry stretch next week could become more of a concern, especially in Argentina that is still recovering from drought.

The other consideration is the colder-than-normal surface water building in the Pacific Ocean as a weak La Nina is developing. That tends to favor drier conditions across Argentina and southern Brazil during the summertime (December through February). If November turns out to be drier, too, that could cause significant strain for crops. So, the good rainfall that appears to be coming back in early November will be important whether it comes or doesn't.

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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