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09/29/2018, 10:41 am EDT

South America Season 1-3 Ahead

Highlight: Far Northeast Argentina to southeast Brazil wet pattern Executive Summary: The Climate Impact Company season 1-3 ahead forecast for South America is updated. CIC is not expecting major drought for Argentina soybeans/wheat or Brazil wheat. There is some risk of drought for northern Brazil soybeans. Climate discussion:  ENSO will (largely) govern the South America warm season climate. The outlook is reasonably certain that a weak El Nino will develop. However, the character of the El Nino is very much in question. Most of the equatorial Pacific warming present since last MAR/APR the bulk in both the surface and subsurface has been near the Dateline. This includes a surge of warmth into the far eastern equatorial Pacific during MAY/JUN which quickly retreated. Another such eastward surge of warmth has developed the past several weeks. Will the recent sharp warming of the Nino12 SSTA region off the northwest coast of South America continue and spread westward causing El Nino onset? Or will the warming off the northwest coast of South America retreat leaving anomalous warmth near the Dateline to cause El Nino Modoki-climate for the South America warm season. Cautiously, the El Nino Modoki scenario is favored. Somewhat recent El Nino Modoki analog years are 1994, 2002, 2004 and 2009 and the analog years are used to project South America climate to next autumn. Analog year(s) with warm SSTA east of Argentina are favored. Fig. 1: GFDL global SSTA forecast for NOV/DEC/JAN 2018-19 indicates an El Nino (probably too strong) biased toward the Dateline with anomalous warmth off the Argentina Coast as lead (climate) predictors for summer climate across South America. Outlooks: Temperature and precipitation anomaly forecasts for October and November plus DEC/JAN/FEB 2018-19 and MAR/APR/MAY 2019 are indicated. The DEC/JAN/FEB and MAR/APR/MAY outlooks are compared to the previous forecast. October 2018: Wetter than normal climate is projected across far northeast Argentina, Uruguay and southeast Brazil. Far northern Brazil is drier than normal with attendant anomalous warmth. Parts of central coastal Brazil is wetter than normal. Fig. 2-3: The Climate Impact Company temperature and precipitation anomaly outlook for October 2018. November 2018: Anomalous warmth and dryness are projected across central and northeast Brazil for late spring. The wet pattern is established over northeast Argentina to southeast Brazil for spring. Fig. 4-5: The Climate Impact Company temperature and precipitation anomaly outlook for November 2018. DEC/JAN/FEB 2018-19: The meteorological summer outlook is wetter than normal across Bolivia, Paraguay to Uruguay. Some of the wet risk extends to northeast Argentina and southwest/south Brazil. Far northeast Brazil is the dry zone. Anomalous heat is attached to the dry forecast in northeast Brazil. Elsewhere the temperature outlook is near normal although central Brazil and central Argentina may be warmer. The updated outlooks are not quite as hot for Brazil or as wet for southeast Brazil. Fig. 6-7: The Climate Impact Company temperature and precipitation anomaly outlook for DEC/JAN/FEB 2018-19.  MAR/APR/MAY 2019: The meteorological autumn outlook remains warmer than normal across Brazil although not quite as warm as the previous forecast. The outlook is dry across much of Brazil. Drought is likely affecting much of Brazil given dryness of the warm season. The wet zone remains Bolivia to Uruguay and is adjusted wetter from the previous outlook. Fig. 8-9: The preliminary Climate Impact Company temperature and precipitation anomaly outlook for MAR/APR/MAY 2019.