Jul 21, 2010
Brazilian Meteorologists Worried About Developing La Nina
Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.
As a La Nina develops in the eastern Pacific, Brazilian meteorologists are predicting an increased chance of dryer than normal conditions during the Brazilian spring and summer growing season. The last La Nina, which occurred during the 2007/08 growing season, had a minimal affect on the Brazilian crops, but it developed late in the growing season. Its principal affect occurred during the start of the 2008/09 growing season when a prolonged drought afflicted southern Brazil. This La Nina is developing early, even before the growing season has started, and it has the potential to be much more intense than the last one.
During El Nino events, rains from the Amazon Region move southward into central Brazil resulting in good soil moisture and generally high yields. But during La Nina events, some of moisture stays bottled up in northern Brazil and the southward progression of the moisture is generally delayed. Under those conditions, soil moisture in central Brazil may not be adequate for spring planting until sometime in October, which would be a month later than normal. La Nina events also generally cause periods of dryness in central Brazil during the summer.
In southern Brazil, the rainfall is generally the result of frontal systems moving up from the south. During La Nina events the northward progression of those rains can be delayed as it was in late 2008 when the state of Parana remained without measurable precipitation from November 12th until December 31st. The result was of course, a significant reduction in summer crop yields.
The future development of La Nina is still speculation, but the odds of repeating record soybean yields in South America during the 2010/11 growing season seem to be diminishing.