Bright key facts / Demonstrated
A better forecast can start by learning its own mistakes.
New research shows how machine learning can improve the odds in three- and four-week weather outlooks by correcting forecasts that already exist.
- AI’s role
- Probabilistic bias correction learns from earlier forecasts and outcomes to adjust forecast probabilities.
- Documented result
- In the Nature study’s 2025 test, PBC doubled the average ranked probability skill score of ECMWF’s subseasonal AI system across the tested variables and lead times.
- Important limitation
- This is a gain in a particular measure of forecasting skill, not a claim that the system gets the weather right twice as often.