---
id: "2023-11-14-graphcast-weather"
url: "https://postcutoff.com/e/2023-11-14-graphcast-weather/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2023-11-14"
date_precision: day
category: science
importance: 4
confidence: high
status: [Result confirmed]
verification: Peer-reviewed
sources: 3
editor: human editor
human_review: null
version: "2026-10-04"
---

As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/e/2023-11-14-graphcast-weather/

# 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

## 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.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): in its training data
- Claude Opus 5.5 (training cutoff June 2026): in its training data
- Gemini 4 Hydrogen (training cutoff March 2026): in its training data
- Grok 4.7 (training cutoff May 2026): in its training data

## Sources

1. [Learning skillful medium-range global weather forecasting (Science)](https://www.science.org/doi/10.1126/science.adi2336) (science.org, paper)
2. [DeepMind: GraphCast](https://deepmind.google/blog/graphcast-ai-model-for-faster-and-more-accurate-global-weather-forecasting/) (deepmind.google, official)
3. [NOAA deploys new generation of AI-driven global weather models](https://www.noaa.gov/news-release/noaa-deploys-new-generation-of-ai-driven-global-weather-models) (noaa.gov, official)

## Changes

- 2026-09-29 (filed): Created

## Related

- 2026-08-06: [DeepMind open-sources WeatherNext 2 and WeatherNext Cyclones with a Nature paper showing ~1 extra day of hurricane warning](https://postcutoff.com/e/2026-08-06-weathernext-open-source/index.md)
- 2025-02-25: [AI weather forecasting goes operational](https://postcutoff.com/e/2025-02-25-ecmwf-aifs-operational-ai-weather/index.md)
- 2024-12-04: [GenCast: diffusion-based ensemble forecast beats ECMWF's ENS on 97% of targets](https://postcutoff.com/e/2024-12-04-gencast-ensemble-weather/index.md)