Swell Period - National Weather Service vs. Windy Models

[jstu23]

Curios as to why specifically swell period vary to drastically between the national weather service and Windy so much. In the pictures you'll see the forecasts for the same days. Windys wave periods are over triple the NWS

[idefix37]

@jstu23
You compare 2 waves models which are different.
The NWS, the US weather department, probably relies on GFS-wave model.
In the Windy forecast table you selected the waves model from ECMWF, the European weather service.
And the difference is not so important 2ft for a model and 3ft for the other one.

[jstu23]

@idefix37 The GFS & ECMWF are very similar. My question isn't much about wave height but more about wave period

[idefix37]

@jstu23
Sorry you were mentioning the wave period indeed. I just remember these 2 models don’t compute the wave period in the same way.

[idefix37]

@jstu23
This thread may explain the difference
https://community.windy.com/topic/3603/different-definitions-for-the-wave-periods-are-shown?_=1711135608499