Heavy Rainfall Expected in Chile, Argentina and Surrounding Regions

Over the next week, influenced by a cyclone and cold air (Fig. 1), regions including central and southern Chile, northeastern and southwestern Argentina, southern Paraguay, western Uruguay, and southern Brazil will experience moderate to heavy rain, with some areas facing torrential rain to extremely heavy rain in central Chile. Southern Chile and high-altitude areas, along with southwestern Argentina, will see moderate to heavy snow, with isolated regions experiencing blizzard or severe blizzard conditions. The cumulative precipitation in most of these areas is expected to range from 30 to 70 mm, with some parts receiving 90 to 130 mm, and localized areas in central Chile, northeastern Argentina, southern Paraguay, and southwestern Brazil may see 150 to 200 mm (Fig. 2). From the 15th to the 18th, a significant temperature drop of 4 to 6°C is anticipated across much of central and southern South America, with parts of central Chile and central Argentina experiencing a more pronounced drop of 8 to 10°C. These regions will also be accompanied by winds of 4 to 6 on the Beaufort scale, with gusts reaching 7 to 9 (Fig. 3).

Figure 1: 500 hPa Geopotential Height (contours, units: dagpm) and 850 hPa Wind Field (wind barbs, units: m/s) on June 15, 2025

Figure 2: Forecast of Accumulated Precipitation from June 13 to 20, 2025 (Unit: mm)

Figure 3: Forecast of Maximum Gusts in 24 Hours on June 15, 2025 (Shaded, Unit: m/s)

Author: Min Yue                                 Reviewer: Liu Xiaobo 

English reviewer:Wang Yi                                                                        Issue approver:Dai Kan