The Great Lakes Wave forecasting system uses the WAVEWATCH III model to provide several wave parameters made available via gridded and point outputs. Two runs are performed: an early run (GLW), generating forecasts up to 84h, at 00Z, 06Z, 12Z and 18Z, forced with NCEP's regional NAM model winds; and a late run (GLWN), generating forecasts up to 144h, at 03Z, 09Z, 15Z and 21Z, forced with winds from the National Forecast Digital Database (NDFD). Output wave data made available via NCEP's NOMADS consist of 3hrly gridded wave parameter fields.