GraphCast: ML weather model beats the world's best physics-based 10-day forecast on 90% of targets
GraphCast (Science, Nov 2023), a graph neural network trained on ECMWF reanalysis data, produced 10-day global forecasts in under a minute on one TPU. It beat ECMWF's HRES, the leading deterministic physics model, on 90.3% of 1,380 verification targets. It later became the basis of NOAA's operational AIGFS.
Key facts
- Beat HRES on 90.3% of 1,380 targets (89.9% statistically significant)
- 0.25° resolution; a 10-day forecast in under a minute on a single TPU v4
- Basis of NOAA's operational AIGFS (Dec 2025), which uses ~99.7% less compute
Science result
- Field
- climate-weather / medium-range weather forecasting
- Problem
- Global medium-range weather prediction
- Result
- Learned model outperforming the top operational physics-based deterministic forecast on most variables and lead times.
- AI system
- GraphCast
- Human role
- Human-designed model; forecasts automated
- Verification
- Peer-reviewed in Science; operational adoption
- Status
- confirmed
- Why surprising
- A model trained on 39 years of reanalysis beat decades of numerical weather prediction engineering on most metrics at a fraction of the compute.
What happened
DeepMind showed that a learned simulator could beat physics-based weather prediction on standard skill scores.
Why it matters
It triggered the rapid move of AI weather models into operational forecasting worldwide.
Changelog
- 2026-09-29: created
Related events
- GenCast: diffusion-based ensemble forecast beats ECMWF's ENS on 97% of targets ★★★
- AI weather forecasting goes operational: ECMWF's AIFS (Feb 2025), then NOAA's AI models (Dec 2025) ★★★★
- DeepMind open-sources WeatherNext 2 and WeatherNext Cyclones with a Nature paper showing ~1 extra day of hurricane warning ★★★
- NeuralGCM: Google's hybrid physics-ML atmosphere model matches top weather forecasts and runs decades-long climate simulations ★★★
Sources (3)
- paperLearning skillful medium-range global weather forecasting (Science)
- officialDeepMind: GraphCast
- officialNOAA deploys new generation of AI-driven global weather models
id: 2023-11-14-graphcast-weather · updated 2026-09-29 · open in the interactive timeline