GRIB Model

WW3 Ocean Waves - Multi-grid Wave

Provider:National Centers for Environmental Prediction, NOAA (USA)
Model scope:Global
Update frequency:every 6 hours
Resolution:0.5°, 30.0nm, 55.5km
Model duration:32 forecasts starting at 0 hr, ending at 7 days 12 hrs
Parameters:wind, wind wave, swell, swell/wave combined
GRIB model date:Tue Oct 17 12:00:00 2017 UTC
Download date:Tue Oct 17 16:32:05 2017 UTC
Download delay:4hr 32min


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.

If you are interested in the Mediterranean, please see the DWD Europe model. If you are interested in the North American Great Lakes, please see the WW3 Great Lakes 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.