Data-driven artificial intelligence models are disrupting this landscape, offering improved computational performance and competitive forecasting accuracy.
However, data-driven models for medium-range forecasting have limitations including low effective resolution and a narrow range of predicted variables.
A study compares the physics-based GEM model with the AI-based GraphCast model, showcasing their strengths and weaknesses in global predictions.
GraphCast excels in predicting large scales over longer lead times but suffers from excessive smoothing at fine scales.
A hybrid NWP-AI system is proposed where GEM's temperature and wind predictions are nudged towards GraphCast predictions for large scales while GEM generates fine-scale details independently.
This hybrid approach enhances prediction skill by leveraging GraphCast's strengths while maintaining physically consistent forecast fields.
The system shows improved accuracy in predicting tropical cyclone trajectories without significant intensity changes.
Efforts are underway to operationalize this hybrid system at the Canadian Meteorological Centre.