AI Weather Forecasting: GraphCast, Pangu-Weather, FourCastNet Compared
AI weather models are now in operational use alongside classical NWP. The honest comparison of GraphCast, Pangu-Weather, FourCastNet, AIFS, and what they.
AI weather forecasting models — GraphCast, Pangu-Weather, FourCastNet, AIFS, and successors — went from research demos to operational use over 2023–2025. By 2026, they run alongside (and increasingly compete with) classical numerical weather prediction (NWP) at multiple national meteorological services. The breakthrough is real. The deployment realities are nuanced.
The honest comparison.
What the AI weather models actually do#
The pattern: train a neural network on decades of reanalysis data (ERA5 typically). Input: current atmospheric state. Output: state N hours later. Iterate to produce forecasts.
Key properties:
- Speed. A 10-day GraphCast forecast runs in ~60 seconds on a single GPU. The equivalent IFS run takes hours on a supercomputer.
- Accuracy. Competitive with or better than IFS deterministic on many metrics in the medium range (3–10 days).
- Resolution. Currently 0.25° (~25km). Higher-res variants in development.
- Ensemble. Cheap to run many forecasts; produces useful ensemble outputs.
GraphCast (Google DeepMind)#
The first to demonstrate clear win over operational IFS deterministic at the medium range. Graph neural network architecture. Open-source.
Strengths: strong overall accuracy, particularly on tropical cyclone tracks; open-source.
Weaknesses: standard resolution; some artifacts in physically extreme situations.
Pangu-Weather (Huawei)#
3D Earth-specific transformer architecture. Competitive accuracy. Asian regional benchmarks particularly strong.
Strengths: excellent for tropical cyclones; faster inference than GraphCast.
Weaknesses: deployment infrastructure less widely supported outside Huawei stack.
FourCastNet (NVIDIA)#
Adaptive Fourier Neural Operator. Earlier model, retired or superseded but historically important.
AIFS (ECMWF)#
ECMWF’s own AI model. Iterating quickly. Integrated with ECMWF’s operational infrastructure. Increasingly the default AI forecast at the national meteorological service level.
What they’re good at#
- Medium-range deterministic forecast (3–10 days)
- Tropical cyclone track guidance
- General atmospheric pattern prediction
- Ensemble generation (cheap to produce many runs)
What they’re not (yet)#
- Sub-daily skill comparable to high-resolution regional models for severe weather
- Convection-permitting forecasts (HRRR, AROME, regional models still better at 1–4km)
- Extreme event physics — some research suggests AI models underestimate the most extreme tails
For most operational uses, the classical models still anchor the forecast chain. AI models are added as an additional source of guidance.
Where the operational shifts are happening#
Energy. Wind and solar forecasting use AI weather extensively. The cost-benefit is compelling.
Aviation. Long-range planning uses AI weather guidance; convective and short-range still depend on classical models.
Insurance. Cat modeling integrates AI forecasts for medium-range guidance; classical models for the convection details.
National weather services. ECMWF, UK Met Office, NOAA, JMA, and others run AI models alongside classical NWP and combine.
The hardware reality#
Running a single GraphCast forecast: ~1 minute on an A100/H100. Producing operational forecast guidance at scale across many regions: still meaningful compute, but vastly less than IFS.
This changes the economics of forecast production. Smaller national meteorological services can produce ensemble forecasts that would have required supercomputers in the classical paradigm.
What we ship for weather-dependent clients#
For operational forecasting engagements via our data engineering practice:
- Hybrid pipelines that consume both classical NWP and AI model outputs
- Post-processing layer that combines for the specific use case
- Site-specific bias correction
- Probabilistic forecast generation
- Application integration with the operational decisions
The 2026 outlook#
The trajectory:
- AI models continue improving on accuracy benchmarks
- Higher-resolution variants under development
- Convection-permitting AI models (still ahead of us)
- Tighter integration of AI and classical for hybrid forecasts
The classical NWP infrastructure isn’t going away. The combination is the future. The clients that build pipelines that consume both win.
Where the work is#
For organizations using weather data:
- The model choice (classical, AI, hybrid) is part of it
- The data engineering (ingestion, normalization, query, integration) is most of it
- The use-case-specific post-processing earns the gain
- The operational integration delivers the value
Our weather data pipelines notes cover the data engineering.
AI weather models are operational and improving. The integration determines whether you capture the value. Our team builds operational forecasting platforms across classical and AI sources. Tell us about the use case.