South America: Exceptional water deficits forecast for northern Brazil; water surpluses in northern Argentina

Exceptional water deficits are forecast to persist across northern Brazil, Suriname, French Guiana, coastal Peru, western Bolivia, and northern and southern Chile, as seen in the 12-month map (below). Surpluses are forecast to emerge in Ecuador and northern Peru. Surpluses are also forecast for southern Brazil, Paraguay, Uruguay, and Argentina, and are expected to increase in extent and severity with exceptional surpluses in central Argentina.

Amid a myriad of national crises - crippling recession, presidential impeachment proceedings, and a corruption scandal - heavy rainfall fell over the depleted Cantareira reservoir in Brazil's populous southern state of Sao Paulo. It will take more than one good rainy season, however, to rescue the region and some water refugees have decided to move. Across the Amazon Basin in the north exceptional water deficits persist. Scientists at the University of Edinburgh have determined that prolonged water shortages in tropical rainforests could kill off the tallest trees by causing the breakdown of the transport system that takes water from soil to the leaves.

Evident in the 3-month maps (below) for the same 12-month period is the forecast of a shift from deficit to surplus in northern South America primarily from March through May. (It should be noted that forecast skill declines with longer lead times.)