NOTICE:
The Global Wave Ensemble System (GWES) was discontinued on 23
Sep 2020 and has been replaced by an improved GEFS-Waves,
consisting of a one-way nesting of the WAVEWATCH III system with
the recently upgraded GFS Ensemble Forecast System. The NOAA
press release on the upgrade is
here, and information on GEFS is available
here.
The GEFSv12 Service Change Notice (issued 8/20/2020, PDF) is
here, and you can find information on the evaluation of the GEFS-Waves portion
of the GEFS system in the
Model Evaluation Group (MEG) Summary page on the
GEFSv12 upgrade
here.
The model data is available four times a day (0, 6, 12, 18)Z from:
-
Production FTP (gefs.YYYYMMDD -->cycle-->waves)
-
NOMADS (Ocean Models-->GFS Ensemble Wave-->(grib filter or https file download).
Details on the products can be found
here (scroll down to GEFS - Wave - Global).
www.nws.noaa.gov 
