25 May 2018

The 12-month forecast through January 2019 indicates water deficits of varying severity for much of the continent, with large pockets of exceptional deficit in Brazil, including the states of Amapá, Pará, Maranhão, Acre, northeastern Mato Grosso do Sul, and São Paulo. Intense deficits are also forecast for southern Venezuela, southern Guyana, Suriname, French Guiana, the Argentine Pampas, Chile, and along many rivers.

Surpluses are expected in Huánuco Region in central Peru, Peru’s border with Bolivia and into central Bolivia, in Brazil’s easternmost tip, and in Patagonia surrounding O’Higgins/San Martín Lake.

The 3-month maps (below) for the same 12-month period show the evolving conditions in greater detail.

Though the extent of exceptional deficit is forecast to diminish in South America over the next several months, large pockets of intense deficit are forecast for Brazil in Acre, Rondônia, Pará, Maranhão, Tocantin, Goiás, western Minas Gerais, northern Mato Grosso do Sul, and São Paolo. Deficits are also expected to be intense along many rivers. Intense deficits are also forecast for southeastern Venezuela; southernmost Ecuador; along a narrow path from Lima, Peru through northern Chile; southern Bolivia; the Río Paraná in Paraguay; and Tierra del Fuego. Severe to extreme deficits are forecast in Cordoba, La Pampa, and southeastern Buenos Aires Provinces, Argentina. Uruguay will transition from deficit to mild surplus.

Intense surpluses will persist in Peru’s Huánuco Region and moderate surpluses in Loreto. Primarily moderate surpluses are forecast for northern Guyana, Brazil’s easternmost tip and southern Espírito Santo, the border between Peru and Bolivia, northwestern Argentina and along the Río Salado, and surrounding O’Higgins/ San Martín Lake in Patagonia.

From August through September moderate to severe deficits are forecast across the northern bulk of the continent, and large pockets of exceptional deficit are expected to persist in many of the aforementioned states of Brazil and in northern Chile. Deficits in the Argentine Pampas will downgrade. Surpluses in Peru’s Huánuco Region will transition to both deficit and surplus, and surpluses in eastern Río Grande do Norte, Brazil will downgrade. Surpluses of varying severity are forecast for southeastern Peru into Bolivia; northwestern Argentina and the Río Salado in northeastern Argentina; between the Ríos Colorado and Neuquén in southern Argentine; and surrounding O’Higgins/ San Martín Lake in Patagonia.

In the final quarter – November through January – deficits will moderate overall and much of southern Brazil will transition to near-normal conditions, but extreme deficits will emerge in Los Ríos Region in southern Chile.

(It should be noted that forecast skill declines with longer lead times.)

Drought conditions in Brazilian grain-producing states threaten this season’s so-called “second corn," the winter corn crop planted in rotation after soybeans. Mato Grosso, the country’s leading grain producing state, is expected to lose up to 15 percent of its second corn crop. Paraná, the second-largest producer, went almost three weeks without rain last month. Rainy conditions delayed soy harvesting in many areas, which pushed back the sowing of second corn making it more vulnerable to drought.

Likewise, estimates for the 2018/19 Brazilian cane crop dropped around three percent this month due to drought-inflicted crop damage. If harvests are as low as currently projected for Brazil's center-south region - the world's largest sugar producing region - this year’s sugar production could be the region’s smallest since 2010, pushing ethanol production down as well.

After a growth season plagued by drought, recent heavy rains in the agricultural Pampas region of Argentina slowed this month’s harvesting of winter soy and corn. Drought conditions in Argentina, as well as in parts of Brazil, have spiked corn prices, prompting some Brazilian farmers to pre-sell their 2019 crop before the 2018 crop is even harvested, locking in the high prices. Gambling that the weather will cooperate, some farmers have sold more 2019 crop than 2018.

Severe drought since the beginning of the year has pushed Uruguay’s soy harvest estimates down 40 percent from the USDA’s original figures.

There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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Many analyses reported in ISciences-authored blog posts are based on data generated by the ISciences Water Security Indicator Model (WSIM). Other sources, if used, are referenced in footnotes accompanying individual posts. WSIM is a validated capability that produces monthly reports on current and forecast global freshwater surpluses and deficits with lead times of 1-9 months at 0.5°x0.5° resolution. This capability has been in continuous operation since April 2011 and has proven to provide reliable forecasts of emerging water security concerns in that time-frame. WSIM has the ability to assess the impacts of water anomalies on people, agriculture, and electricity generation. Detailed data, customized visualizations, and reports are available for purchase.

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