[scellus]

ECMWF runs many such models at their site, a run two or four times per day, and they have verification statistics too, no need to doubt the accuracy.

The Google model is probably the best so far but ECMWF's own diffusion model was already on par with ENS and many point-forecast models (graph transformers, not diffusion) outperform state-of-the-art physical models.

What is missing is initialization directly from observations. All the best-performing models initialize from ERA5 or other reconstruction.