Waves vs Swell
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Hi,
I’ve used windy for sailing, channel crossing etc - all good.
What I’m confused about is “Waves”. For instance it predicts 1.5m - 2.5m WAVES in Biscay today (but there aren’t!) More generally if Windys WAVES were ever real, no sailor would leave harbour.
How does it arrive at its wave values?
What does windy class as a wave?
I can see its relation to wind, but how much fetch is allowed for in the prediction?
How does windy give 0m swell and 1.5m Waves off shore at the same time (the swell/wave values seldom match)Any help understanding this would really be great!
Thanks
Greg
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@Greg-Livermore said in Waves vs Swell:
What I’m confused about is “Waves”. For instance it predicts 1.5m - 2.5m WAVES in Biscay today (but there aren’t!) More generally if Windys WAVES were ever real, no sailor would leave harbour.
Hi,
I don't know where you observe wave heights in Biscay.
How can you say that the wave heights don't match the ECMWF wave model forecasts? Are you currently sailing in the middle of the Biscay zone ?
By the way, the GFS and ICON wave models provide roughly the same heights. Windy's default wave model should therefore be close to reality.
Personally, I don't remember encountering offshore sea conditions that were completely different from Windy's forecasts.How does it arrive at its wave values?
Wave heights and other wave parameters come from major waves models.
What does windy class as a wave?
The height of waves is the significant height i.e. the mean height of the third of highest waves.
https://codes.ecmwf.int/grib/param-db/140229I can see its relation to wind, but how much fetch is allowed for in the prediction?
The influence of the fecht is compute by the model.
How does windy give 0m swell and 1.5m Waves off shore at the same time (the swell/wave values seldom match)
If you have 1.5m waves and 0m swell, that means waves are only wind waves produced by local wind.
https://community.windy.com/topic/17449/swell?_=1745317399920 -
@idefix37
In addition here is the weather prediction from the Met Office for the Biscay zone today.
The sea state is based on Douglas scale
https://en.m.wikipedia.org/wiki/Douglas_sea_scale
You see that the default waves model in Windy was in line with the Met Office forecast
