Microsoft ships Aurora 1.5, beating ECMWF ensembles on 88.9% of targets with open weights on Hugging Face

Microsoft Research·high signal

Aurora 1.5 extends Microsoft Research's open Earth-system foundation model with 22 additional weather variables, hourly temporal resolution, and probabilistic ensemble forecasting. Microsoft reports it outperforms the European Centre for Medium-Range Weather Forecasts ensemble on 88.9% of evaluated targets, with the ensemble median cutting tropical-cyclone track error by roughly one third on storms including Hurricane Helene. Code is on GitHub and checkpoints on Hugging Face — a genuinely open frontier scientific model, which is rare enough to note.