An absence of La Niña conditions in October allowed Brazil rainfall to develop much more normally than last year. Sufficient rain fell to bolster soil moisture in much of the nation with some areas in the south getting a little too much rain for a while. In the meantime, Argentina continued to fight dryness, but it was not as serious as that of 2020.
Fear ran through the marketplace during much of 2021 that drought would first harm US production and then it would impact South America. Rumors of significant drought in North America during the summer of 2021 were rampant in the winter and spring, and that, along with low grain and oilseed stocks, led the marketplace in an impressive run-up in commodity futures prices. Well, several months later it has been learned that production cuts were not nearly as bad as feared and the corrections in market valuations began. Soybeans were the most inflated trade of the year and the market is still bringing that market valuation back into a more realistic range.
The fear of a second year of La Niña in South America leading to another year of delayed seasonal rains and then poor rain amounts in southern Brazil during its spring season fed into the market frenzy early in 2021. As time has rolled along it became obvious that La Niña was not evolving like that of 2020, resulting in a mostly normal evolution in seasonal rainfall. Not only did rain fall in a timely manner during October, but it also occurred in some significant quantities.
Portions of interior southern Brazil and southeastern Paraguay received well-above-average rainfall during the first three weeks of October. The rainfall was significant enough to seriously reverse the moisture deficits that had built up in the previous six months. Moisture deficits in southern Paraguay and interior southern Brazil ranged from 200 to more than 500 millimeters, which is roughly 8 to nearly 20 inches. That is how much less than usual rain fell from April 1 through Oct. 1. Those are some impressive amounts and earlier this year that seemed like an impossible task to replace the moisture lost.
However, in just a few weeks interior southern Brazil and Paraguay reported nearly that much rain, which helped greatly in restoring favorable soil moisture. Additional rainfall must occur to fully restore soil moisture to normal, but that might not occur as easily as the first 8 to 20 inches because normal rainfall is steadily rising as each day goes by. The rain reported in October was a Godsend for southern Brazil and will actually help to deter the onset of crop moisture stress this late spring and summer if the weather pattern turns drier biased because there is now a more favorable amount of moisture in the ground to carry crops for a while without significant rainfall.
La Niña years, like this one, do not usually allow normal rain to fall in southern Brazil. The region including Rio Grande do Sul, southern Paraguay, eastern Argentina and Uruguay typically has below-average rainfall during November, December and sometimes January. La Niña has only recently begun to influence world weather patterns and it may take a little more time in early November for the phenomenon to fully kick in, but when it does the October rainfall will help delay the onset crop moisture stress because it will take a little longer for the region to turn dry once rainfall diminishes since the ground is now almost completely saturated with moisture.
Accompanying La Niña this year will be a solid 22-year solar cycle also promoting below-average precipitation in southern Brazil. There is also evidence of poor rainfall in the 18-year cycle. All three of these patterns will work together to create less-than-usual rainfall in the next few months in southern Brazil. The drying bias might be welcome in the near term, but if the pattern prevails, as it might, there will be a fair chance that dryness may take longer to evolve than usual because of the abundant October rainfall eliminating long-term moisture deficits that had prevailed during the April through September period.
Argentina weather might also be better than usual in early November while La Niña is still evolving. The timeliness of rain during the month might initially offer better spring and summer crop planting and emergence conditions and may stave off a more threatening dry pattern for a while. Argentina might yield better this year than last year depending on how well rainfall is distributed over the next several weeks.
Brazil’s increased area planted to summer crops also will help counter yield losses that might occur in southern Brazil from dryness this summer, but the timeliness of rainfall and its distribution will be critical in determining yields.
In the meantime, research continues ongoing about the prospect for dryness in the US Plains, western Midwest Corn Belt and southwestern states this winter and next spring. The two-year La Niña event along with the 22-year solar cycle and a drier-biased 18-year cycle already playing out along with the negative phase of Pacific Decadal Oscillation are all hinting that dryness may return or remain in the central United States this winter into next spring. The pattern will continue to promote wet-biased conditions in portions of the eastern Midwest and there may be a few weather systems impacting the southwestern Canada Prairies and a part of the northern US Plains as well. Southwestern portions of the United States; including southern California and the southern Rocky Mountain region may also have a drier bias this winter and spring along with a drier bias in the southeastern states during spring as well.
The bottom line remains that Brazil and Argentina may still have some production issues in 2021-22 because of La Niña, but the losses might not be as significant as those of this past year. The better bottom line in South America might be good news for commodity futures trade and prices during the winter and early spring ahead of what might become a challenging year for parts of the United States and a part of Canada once again.