JMA's Global Spectral Model
Global Spectral Model Upgrade History since 1988
Model upgrade history
Global Spectral Model Verification Results
Monthly-mean error maps
Latest verification results are available at the WMO Lead Centre for Deterministic Forecast Verification (WMO-LCDNV):
https://wmolcdnv.ecmwf.int/
Archived verification results from January 2011 to April 2019