South America Calling

Outside of southern Brazil, Uruguay and portions of eastern Argentina, dryness and drought have been the two words most commonly used to describe the weather situation over South America's primary growing areas so far this season. Though planting should be increasing in early October with corn and sunflowers in Argentina and first-crop soybeans in central Brazil, that has been off to a slow and protracted start. Very limited areas have decided to start planting as conditions have been so poor.

Central Brazil is especially vulnerable because there is literally no soil moisture in the region. After enduring five to six months of near complete dryness in the states of Mato Grosso, Goias, and Minas Gerais, producers have to get some rain before they can plant to avoid the risk of germination after a brief rain only for the crop to dry up in the dry soils. Isolated showers have occurred but have been incredibly spotty to start off the wet season.

Argentina has not been in great shape either. Though fronts have gone through with regularity over the course of the spring, precipitation has been limited to far southern and eastern areas of the country. High production areas from Cordoba to northwestern Buenos Aires, and Santa Fe have had less than 50% of normal rainfall during the last 90 days, amounting to less than 50 millimeters (about 2 inches) while some areas have not had a single drop of rain in that time. There have been reports of producers abandoning their winter wheat in the drought and the first round of corn planting has been slow in these areas for obvious reasons.

Producers in Argentina plant corn in two separate windows. The first round is from September to October. The second window is from December to January. A long growing season allows producers to reduce risk by planting in multiple windows, to avoid complete catastrophe from a bad window of weather that can sometimes get very dry.

Unfortunately for producers this year, they aren't getting much of a choice when soil moisture is so low to begin the year. Soybeans are planted mainly in November and December. Argentina, along with central Brazil need to see rain picking up quickly. And they may see it starting next week.

A system will start to move into northern Argentina on Oct. 6, spreading some showers there. The main impulse from the storm will build showers across more of the country for Oct. 7-8. Rainfall amounts are forecast to be in the 30- to 60-mm (about 1.2- to 2.5-inch) range with some areas that will likely see more than that.

That is enough to moisten soils and improve soil moisture, but not eliminate the drought for most of the region. And models have been tightening the location of the best rainfall. Southern areas like La Pampa and southern Buenos Aires are no longer expected to see rainfall out of this system. And the southern end of the range has been creeping up toward Cordoba.

Some areas that are in the extreme drought may be left dry. But even if they do get rainfall, they will need more in the coming weeks to allow producers to ramp up their planting and save their wheat.

From there, the storm will push a front into southern Brazil for a couple of days of rain. But unlike previous fronts that have fizzled out in southern Brazil, this one is forecast to penetrate deep into central Brazil, producing widespread showers from Mato Grosso to Minas Gerais by the end of the week. Showers may even start developing over northern Brazil, in the still-important states of Tocantins and Bahia. Long-range models mark this system as the true start to the wet season rainfall, with showers continuing thereafter the rest of the month. For the following week, most models paint the region as receiving 30-60 mm of precipitation, a decent start.

The European model is the most bullish of the long-range models, showing above-normal precipitation going into November. But the American GEFS and CFS models and the Canadian CMC model show below-normal precipitation during the month, even with the burst of showers forecast starting late next week.

Despite the improved outlook for both Argentina and central Brazil with the system for next week, there are still some concerns about the weather situation for both areas as we get deeper into the season.

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

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