AI and the World's Hard Problems · Earth & climate science · Nature · 2026-10-14
Advancing subseasonal forecasting with machine learning
Forecast skill drops sharply at subseasonal timescales of 2 to 6 weeks ahead. The authors introduce probabilistic bias correction, a machine learning framework that learns to correct historical probabilistic forecasts, and apply it to ECMWF's leading dynamical and AI models. It doubled the modest subseasonal skill of the AI Forecasting System and improved the dynamical model for most pressure, temperature and precipitation targets, and in ECMWF's 2025 real-time competition its global forecasts were the best.