According to World Meteorological Centre Beijing (WMC-BJ), affected by a converging cyclone (Figure 1), it is expected that from April 22 to 25, regions including southeastern Bolivia, most of Paraguay, northern Argentina, and southwestern Brazil will experience moderate to heavy rain, moving from west to east. Specifically, the Upper Paraguay Department and Guairá Department in Paraguay, as well as the Formosa Province in Argentina, will see torrential rain, accompanied by severe convective weather such as short-range heavy precipitation and thunderstorms with strong winds.

Figure 1: 500 hPa Geopotential Height (Isopleths) and 850 hPa Wind Field (Wind Barbs) at 12:00 UTC, April 24, 2025

The accumulated precipitation in most of these areas is anticipated to be between 20 and 50 mm, with some regions receiving 80 to 150 mm, and localized areas exceeding 250 mm. Additionally, influenced by the interaction of warm and cold air masses, southern Chile will also experience moderate to heavy rain, with localized torrential rain (Figure 2).

Figure 2: Forecasted Accumulated Precipitation from April 22 to 25, 2025 (Unit: mm)

Source: WMC-BJ

Editor: JIANG Zhiqing