Spire AI-S2S: A more accurate, differentiated sub-seasonal weather forecast
Published May 28, 2026A 200-member generative AI ensemble, built fully in-house, independent of public sub-seasonal models, and verified to outperform the ECMWF’s sub-seasonal-range forecasts (S2S)* across all forecast lead times, most notably weeks 3-6, when other models trend to climatology.
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