Heavy rain and thunderstorms will expand across central South America with the greatest threat for flooding focusing on northern Argentina and eastern Paraguay into Friday night.
A storm system and its cold front will be the culprit behind drenching rain and thunderstorms spreading from northern Argentina to Uruguay into early Friday morning, then pressing northward into southern Brazil and Paraguay Friday into Friday night.
While heavy rain will be more localized around Cordoba, Buenos Aires and Montevideo, numerous downpours will occur to the north with rainfall amounts averaging 25-75 mm (1-3 inches). Flash flooding may ensue in low-lying and poor drainage areas.
"Thunderstorms can also produce isolated wind gusts of 65-80 km/h (40-50 mph)," stated AccuWeather Senior Meteorologist Dale Mohler.
The greatest concern for the rain to total 75-150 mm (3-6 inches) and lead to more widespread and serious flooding will center on far northeastern Argentina, eastern Paraguay and western parts of the Brazilian state of Rio Grande do Sul. Even locally higher totals cannot be ruled out.
Runoff from the heavy rain may flood corn and soybean crops in southern Brazil and eastern Paraguay, added Mohler. "Farmers may be forced to replant crops, but it is early enough for them to do so if needed."
"The heaviest rain will fall north of the prime crop land in Argentina," continued Mohler.
Drier air will work into central South America this weekend as the rain and thunderstorms shift northward into more of southern Brazil and Bolivia.