Removed, April 5th, 2022.
The WW3 model was removed from the server cluster today, April 5th, 2022.
As noted, over a year ago, the ocean parameters in GFS serve as the replacement for the old WW3 model.
Deprecated, March 22nd, 2021.
Note that GFS was updated to v16 on March 22nd, 2021. As part of this update, the old WW3 model has been greatly improved and is now incorporated directly into GFS.
This WW3 old model has now been deprecated and will be removed in the future. Please start to use the wave data available in the GFS model, instead of this model.
This model forecasts ocean conditions. The model includes parameters that forecast ocean primary swell, secondary swell, primary wave and wind waves.
The operational ocean wave predictions of NOAA/NWS/NCEP use the wave model WAVEWATCH III using operational NCEP products as input.
While this model is global, many seas and all lakes are not covered. For example, the Mediterranean is not covered by this model.
This model contains parameters that describe the primary swell, the secondary swell, wind waves and the primary wave. Wind waves are self explanatory - they are the waves caused by the wind. Often on the ocean, there is more than one swell wave present, for example when an area is affected by more than one strong weather system. The largest swell wave that is present is called the primary swell. The second largest swell wave present is the secondary swell.
An interesting parameter is the primary wave, which is either the primary swell or the wind wave, whichever is greater for each point in the model. (This description may be simplified, but I believe captures the essence of what the primary wave represents.)
Please note that the winds in this model have been adjusted to be at the 10m level. The original source for this data are GRIB files at the NOAA site. Those GRIB files indicate that the wind is at the surface. However, the wind is documented as being at 10m and this has been verified through contact with a member of the WW3 team. The LuckGrib server adjusts the wind level to be at 10m, where it appears to belong.
Also, please note that this model is called Multi-grid Wave at the NOAA site. It is also referred to as NWW3, NOAA-WW3.