AI weather models out-track ECMWF's physics ensemble on tropical cyclones, preprint finds

Researchers at Inria, Sorbonne Université and the insurer AXA compared three AI weather models — GenCast, FourCastNet 3 and FGN — with ECMWF’s operational physics-based ensemble, IFS-ENS, across 178 tropical cyclones, in a preprint posted Oct 15. FGN beat IFS-ENS on probabilistic track scores for about 90% of the 41 storms retained from 2025, the authors report. The AI models still showed biases in storm intensity and errors in ensemble spread, they found.