After no rain for almost a month, Santiago can expect some wet weather for the start of the week. At the same time, a blast of cooler air pushes northward, bringing a chill across Chile and the Pampas for mid-week.
A low pressure developing over the Pacific Ocean will move into central Chile on Sunday, bringing with it some light to moderate rainfall; the higher elevations of the Andes will see a round of snow.
"Rainfall amounts west of the Andes will be on the order of 6 to 12 mm (0.25 to 0.50 of an inch)," according to AccuWeather Senior Meteorologist Rob Miller. "Snow amounts in the Andes can reach or exceed 30 cm (12 inches)".
Although the expected rainfall amounts for places like Santiago are relatively small, rain has been in short supply over the last few months.
Despite normally being considered the hear of Chile's "wet season", less than 25 mm (1 inch) of rain fell in Santiago during the month of July. The beginning of August was relatively wet with about 100 mm (4 inches) of rain in about a week, but once again the city has remained dry for the second half of August and into early September.
The incoming rain "will not erase the drought, but any rain is welcome and needed," Miller said, "especially with them heading towards the dry season."
The rain and snow is expected to continue to be light throughout central Chile Sunday and into Monday, before moving eastward across central Argentina and into southern Brazil. However, once crossing the Andes, the system will become significantly weakened.
Rain will be much spottier, with little accumulation in places like Cordoba and Rosario in Argentina; the same is true for parts of Uruguay and southern Brazil.
Meanwhile, a cold front shifts northward from southern Chile and Argentina Sunday and Monday. Pulling in some cool air behind it, temperatures will begin to drop down on Monday in Santiago.
"With afternoon highs only around 14 C (58 F) on Tuesday, temperatures will be about 5.5 C (10 F) below normal," Miller said.
Santiago is not the only city bracing for this shot of cool air. Temperatures in Buenos Aires will bottom out on Wednesday and Thursday, as highs only climb into the middle teens Celsius (upper 50s in Fahrenheit). Cordoba and Rosario will see a similar drop in temperatures for the middle of the week.
The cooldown, however, is expected to be brief. Temperatures should return to normal with a westerly push of warmer air will reach the Andes and the Pampas by the end of the week.