A potent storm system will bring the threat for flooding rainfall to areas from far northern Argentina and Bolivia through Paraguay and southern Brazil.
The storm system will emerge from the Andes Monday night into Tuesday spreading heavy rain and thunderstorms across far northern Argentina into Paraguay.
The storm will track slowly eastward leading to locally heavy rainfall in northern Paraguay and southern Bolivia on Wednesday. These areas can expect 25-75 mm (1-3 inches) of rainfall within a 24 hour time period leading to enhanced risk for flooding.
The heavy rain will shift across central and eastern Bolivia into Thursday while also spreading into Mato Grosso do Sul and southern Mato Grosso.
From later Thursday into Friday the heaviest rain will fall over eastern Brazil, impacting the states of Minas Gerais, Espirito Santo and southern parts of Bahia.
Total rainfall this week will average 25-75 mm (1-3 inches) with localized amounts up to 150 mm (6 inches).
Showers and thunderstorms will shift further north across Brazil this weekend allowing the hardest hit areas to recover from any flooding problems.
While flooding is a concern, much of the rain will be beneficial for eastern Brazil, an area that is in the midst of an extreme drought that has devastated reservoir levels.
Areas impacted by this drought include Sao Paulo and Belo Horizonte where rainfall has averaged less than 50 percent of normal since the start of the year. Some of the hardest hit areas have received less than 10 percent of their normal rainfall for the year, leaving parts of the region more than 890 mm (35 inches) of rain below normal.
New rainfall amounts of 25-75 mm (1-3 inches) will begin the slow process of rebuilding reservoir supplies, however many months of above normal rainfall will be needed erase the extreme drought conditions that have gripped the region.