South America: Exceptional water deficits to persist across northern South America, particularly the Amazon Basin

The Big Picture
Exceptional water deficits are forecast to persist across northern South America, particularly across the Amazon basin, as seen in the 12-month map (below). Surpluses are forecast in central Paraguay, central and western Argentina, Uruguay, and Rio Grande do Sul, Brazil.*

Impacts
Venezuela's Guri Dam, which supplies about 60 percent of the nation's power demand, recently hit a historic low of 243 meters. In an effort to reduce power consumption President Maduro has reduced work hours of public servants and has asked women to air-dry their hair and laundry. "Water is gold now" said one Venezuelan, recounting how he and his desperate neighbors, victims of the nation-wide water shortage that has left faucets dry and created rolling black-outs, hijacked a hotel water truck.

Concern is mounting that the drought in Brazil's Corn Belt could result in a reduced safrinha corn crop, a second crop planted after soybeans, which would put additional strain on Brazilian livestock producers who are already facing record corn prices. Yet another stress point as well, perhaps, for Brazil's President Rouseff who currently faces impeachment proceedings on charges of manipulating government accounts.

In Chile demand for liquefied natural gas rose sharply as hydroelectric generation fell 21.8 percent in February.

Between 800,000 and 900,000 hectares of soybeans will go unharvested in Argentina - the world's leading supplier of soy oil and soy meal - as heavy El Niño rains pounded nearly half of the country's soy fields, destroying crops, delaying harvest, flooding roads, and threatening disease. On April 11 of this year 612 trucks of soy arrived at export docks, down from 4,273 trucks on the same day last year.

Forecast Breakdown
The 3-month maps (below) for the same 12-month period illustrate conditions in more detail. Deficits in Colombia, Venezuela, Guyana, Suriname, French Guiana, and western Brazil are forecast to moderate somewhat April through June. Much of northern Brazil and Chile will continue to experience drought conditions. Surpluses will persist during this period in central Paraguay and Rio Grande do Sul, Brazil. Surpluses are forecast to emerge throughout Uruguay, in the Ibará Wetlands of eastern Argentina, and in the state of Buenos Aires.

From July through September deficits will spread in Ecuador, Colombia, Venezuela, Guyana, Suriname, and French Guiana, which may be severe to exceptional in many areas. Deficits will persist in Peru, Bolivia, Chile, and much of Brazil, though deficits in Chile are expected to be somewhat less severe. Rio Grande do Sul, Brazil may transition from water surpluses to nearly normal conditions. Surpluses will diminish in Uruguay but central Paraguay and much of northern Argentina will remain wet.

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

* Please note that effective March 28, 2016 NOAA changed the initialization procedure for CFSv2 to address issues with unrealistically cold sea surface temperatures in the Tropical Atlantic Ocean. As a result, this month's Watch List is based on an ensemble of 14 CFSv2 forecasts issued after this fix was implemented instead of the normal 28. For more information see http://www.nws.noaa.gov/os/notification/tin16-09cfs.htm and http://www.nco.ncep.noaa.gov/pmb/changes/downloads/CFSv2_Atlantic_cold_bias_problem.pdf.