Forecasting science

AI weather forecasting

In 2023-24, machine learning models started beating traditional physics-based weather models. Here is what they are, why they work, and what they still get wrong.

The paradigm shift

For 70 years, weather forecasting has meant solving the equations of atmospheric physics on supercomputers. Slow, expensive, effective.

In 2023, Google DeepMind's GraphCast beat the industry standard ECMWF model on many metrics. In 2023, Huawei's Pangu did too. In 2024, Microsoft's Aurora. All run on GPUs in seconds instead of hours on CPUs.

This isn't incremental improvement. It's a new paradigm.

How AI weather models work

  1. Start with 40+ years of past weather data (ERA5 reanalysis dataset).
  2. Train a neural network to predict future weather from past weather.
  3. Not physics โ€” pattern learning.
  4. Model learns implicit physics from data.
  5. Result: given current atmospheric state, predict state 6 hours later.
  6. Chain 6-hour steps to get 10-day forecasts.
  7. GPU inference: seconds per forecast.

The three main systems

GraphCast (Google DeepMind, 2023)
Graph neural network. 0.25ยฐ global resolution. 10-day forecasts.
Pangu-Weather (Huawei, 2023)
3D neural network. 0.25ยฐ global. Beats ECMWF on 6 of 8 metrics.
Aurora (Microsoft, 2024)
Foundation model. Fine-tunable for specific tasks (air quality, waves).
FourCastNet (NVIDIA, 2022)
Fourier neural operator. Earlier system, foundational.
Fuxi (Fudan, 2023)
Chinese-developed. Competitive on medium range.
AIFS (ECMWF, 2024)
Official European ML model. Operational since 2024.

What they're good at

What they're still bad at

Why they matter for chasers and safety

What NWS does with them

The training data problem

The interpretability problem

Traditional models: we know why they output what they do (equations).

AI models: we don't. It's a black box.

The future

Learn more