A more active storm track across central and north-central Chile will be one of the biggest stories across South America, following several winters with below-normal precipitation.
Storms crossing the Andes from Chile in Argentina will bring occasional rain to central Argentina but will allow for shots of milder air to build over the region. Overall, Buenos Aires can expect a mild winter with near-normal rainfall.
A corridor of soaking rain and thunderstorms will set up from northeast Argentina into much of Paraguay, northern Uruguay and southeast Brazil throughout the winter.
A strengthening El Niño will result in little or no drought relief across northern and eastern Brazil.
Needed Rain and Mountain Snow Return to Chile
High pressure building to the south of Chile will cause the primary storm track for the winter to be farther north than previous years.
As a result of the shifted storm track, a wet winter is expected across central and north-central Chile. These areas remain in a severe drought and an increase in rain and mountain snow will be beneficial for the region.
According to AccuWeather Senior Meteorologist Jason Nicholls, "The improvement for the drought across central Chile will be gradual. While rains will return to Santiago, the most significant rainfall is expected during the months of July and August."
The mountain snow is expected to increase during July and August, allowing for a much-improved ski season for the resorts central Chile.
Since the start of the year, only 5.6 mm (0.22 of an inch) of rain have fallen in Santiago, a mere 7 percent of the normal.
"During the strong El Niño of 1997, Santiago received 142 percent of normal precipitation during the months of June, July and August and even though the most significant rains will be delayed, similar rainfall totals are possible this year," Nicholls said.
Along with the frequent storm systems, temperatures will be mild as air masses from the Pacific Ocean will dominate over any air arriving from the south or interior.
Stormy Winter With Widespread Rains From Brazil Into Uruguay and Paraguay
Frequent frontal boundaries along with ample moisture from the Atlantic Ocean will lead to an unsettled winter across northern Uruguay, northeast Argentina, Paraguay and southeast Brazil.
This weather pattern will favor above-normal precipitation along with near-normal temperatures. While cold air will be infrequent across this region, above-normal temperatures will be kept at bay by the numerous days of wet and cloudy weather.
Numerous rounds of heavy rain and slow-moving or stalled frontal boundaries will result in a high risk for localized flooding over the next several months.
"The rainfall will be largely beneficial for crops that have already been planted across northern Argentina and southern Brazil; however, if flooding does occur, then quality and quantity of crops will become an issue," Nicholls said.
The surplus of moisture could cause some planting delays in the spring; however, where flooding is not an issue, soil moisture will be at ideal levels for early crop development.
The overall mild winter will also limit the threat for any damaging freezes across the Brazil coffee belt.
Drought to Worsen Across Northern Brazil; Limited Relief Farther South
While parts of southeast Brazil will experience a very wet winter, eastern and northern Brazil will see another winter of near- to below-normal rainfall.
Lesser precipitation amounts are expected across northeast Brazil where drought continues, and drought conditions will worsen through August.
Locations that are expected to see well below-normal precipitation include: Fortaleza, Natal, Recife and Belem.
Near-normal rainfall is expected farther south from Brasilia to Rio de Janeiro and Sao Paulo, but it will not be enough to bring relief from the drought conditions gripping the region.
Meanwhile northwest Brazil will see a more active weather pattern, which will result in above-normal rainfall and also keep temperatures seasonably cool.
Winter to Lack Extremes for Buenos Aires, Central Argentina
Buenos Aires, Cordoba and Montevideo can expect a fairly typical winter that will lack any big extremes.
While cold shots will frequent southern Argentina, central and north-central Argentina and southern Uruguay will experience a near-normal winter with a lack of extreme cold reaching areas as far north as Buenos Aires.
Occasional cold air masses will reach Buenos Aires, Cordoba and Montevideo. However, long-lasting below-normal cold is not expected throughout the winter months.
Frontal passes from the south and a few storms spreading rain in from the west will result in near-normal precipitation but no widespread flooding is expected. Temperatures will average near to above normal across the region due to infrequent cold shots.