Aurora 1.5 adds ensemble forecasts, hourly steps and 22 new variables; beats ECMWF ENS on 88.9% of targets

Microsoft/Aurora

Microsoft released Aurora 1.5 as open source with checkpoints on Hugging Face. It grows from 4 to 26 variables (wind, temperature, humidity, precipitation, radiation and more), forecasts in hourly steps and, through perturbation-based fine-tuning, produces probabilistic ensembles. It is being wired into Microsoft Weather, Foundry and Planetary Computer Pro.

• Outperforms ECMWF's ensemble on 88.9% of evaluated variable and lead-time targets.
• Hurricane Helene 2024: about one-third lower day-5 track error than the original Aurora.
• Trained on ECMWF high-resolution analyses from 2018 to 2023.
• Microsoft Weather serves Windows, Bing, Copilot, Edge and MSN.