Ag Weather Forum

Mostly Favorable Dry Week in South America

Mike Palmerino
By  Mike Palmerino , DTN Senior Ag Meteorologist
Primary southern Brazil and Argentina crop areas have moderate to heavy rain returning to the scene over the next week. (DTN graphic)

After a wet month in November across Brazil and Argentina, welcome drier weather has developed so far in December. This has lessened disease pressure in central Brazil, and has provided better planting conditions in Argentina.

We have now reached the point where more rain would be welcome in central Argentina and southern Brazil, as temperatures have begun to reach the middle 90s Fahrenheit. That tells as that topsoil has dried out. Scattered showers and thunderstorms have started to return to Argentina, and are expected to continue the next few days, with heavy totals expected.

This rain will reach southern Brazil late this week and into early next week. This will maintain favorable growing conditions in these areas. In central Brazil, rainfall is expected to remain limited during the next week. This will reduce disease pressure from building in soybean fields.

The next important situation to monitor will be the weather pattern for the early soybean harvest at the end of December. Although it is too early to make a confident call, there are indications on the longer-range forecast guidance that a wetter weather pattern could develop during the last seven-to-10 days of the month.

In the U.S., late harvest continues. There are still soybeans left in the fields in the Ohio and Tennessee Valleys. Cold and unsettled conditions are expected to continue, with the next chance of some significant precipitation being later in the week. Quality issues and some harvest losses are being experienced. The weather will be favorable for any remaining corn harvest in the Northern Plains and northwest Midwest, with mostly dry and mild conditions.

The sea surface temperature departure in the eastern equatorial Pacific for the month of November was 1.8 degrees Celsius above normal. This is up from 1.4 degrees C above normal observed during the month of October, and is well within the parameter for a weak El Nino, which is judged to be in place when the sea surface temperatures reach 1.0 degree C above normal. We will have our mid-month update next week, which will have details on the sea surface temperatures for the first half of December.

Michael Palmerino can be reached at



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