Madden Julian Oscillation Update: Influence on La Nina and Potential SSW Events
10/29/2025, 1:00 pm EDT
Shifting Climate Pattern Brings Wet Weather to Brazil
11/03/2025, 5:10 am EST
Climate Impact Company Week 2-to-4 South America Outlook
Issued: Friday October 31, 2025
Headline: Trending drier/hotter Argentina; East Brazil rains.
Charts of the day: Are the “weeklies” following the constructed analog precipitation anomaly climate forecasts?
Discussion: The Climate Impact Company constructed analog precipitation anomaly forecasts for South America have a wet bias in Brazil in November shifting east and weakening in December while steadily drying Argentina projections appear.
Week-2 Valid November 9-16, 2025: Wet East Brazil.
Discussion: Upper trough off the coast of Southeast Brazil extends northwestward causing wet weather in East Brazil. Subsidence away from that wet zone dries Northern Argentina and Northeast Brazil.
Week-3 Valid November 16-23, 2025: Wet East Brazil; Hotter Argentina.
Discussion: The persistent upper trough rests on the Southeast Brazil Coast. The trough maintains wet weather in East Brazil with compensating dryness over Northeast Argentina/Southeast Brazil and growing anomalous heat affecting Argentina.
Week-4 Valid November 23-30, 2025: East Brazil stays wet, Argentina hot.
Discussion: Upper air support stays wet on the East Coast of Brazil while Southeast Brazil is dry. Anomalous heat continues across Argentina.