The IRI November briefing says La Niña conditions have arrived, with Nino3.4 sea-surface temperatures near or just below the -0.5°C threshold. Atmospheric signs such as stronger trade winds are only partly in place, so the event is borderline.
A borderline La Niña raises odds of dry US Plains and Argentine risk later, a modest supportive factor for grain prices over the coming months.
After 1,072 past bullish weather events, Wheat (SRW) moved a median +0.2% over 5 sessions (55% higher; middle half -1.4% to +2.3%), and +0.3% over 20.
After 1,465 past bullish weather events, Corn moved a median +0.2% over 5 sessions (54% higher; middle half -1.4% to +1.9%), and +0.9% over 20.
After 1,079 past bullish weather events, Soybeans moved a median +0.3% over 5 sessions (54% higher; middle half -1.4% to +2.0%), and +0.9% over 20.
Moves of each commodity's benchmark from the last close before the event. Historical reads pool past events of the same kind; they describe what happened, not what will. Not investment advice.