wind Force or Sea State ?

[BartW]

in UK you are alway's talking about Wind Force when specifying weather or sea conditions. Most Britisch publications I find on the net have a fixed relation between wind speed and wave hights, and specify just one Force (Fx) figure

we all know that wind speed is not always fixed related to wave hight,

I learned to differentiate two figures,
both on a Beauford or similar scale
- Wind speed = speed of the wind in km/hr or in knots or Bf
- Sea state = wave hight, in meters or feet or a scale similar to Beauford

here is a table of wind speed:
http://www.mumm.ac.be/EN/Models/Operational/Wind/table.php

and a table of wave hight, at the same moment:
http://www.mumm.ac.be/EN/Models/Operational/Waves/table.php

you can see that the Beauford (wind speed) and sea state figure are not the same.


when you're talking about a Force 6
are you talking about the wind speed, or the expected wave hight,
to me, depending on where you are, or from which direction the wind comes, this could make a important difference.

 

[colingr]

The Beaufort scale F1 etc is a wind speed scale. It gives an indication of sea state but only that, an indication. Wave height depends on many variables such as fetch, tide state and direction, how lonf the conditions have been in force, water depth etc etc etc.

 

[BartW]

The Beaufort scale F1 etc is a wind speed scale. It gives an indication of sea state but only that, an indication. Wave height depends on many variables such as fetch, tide state and direction, how lonf the conditions have been in force, water depth etc etc etc.

yes I know, but why do most on here usually use "wind Force", when they are talking about a "sea state" ?

 

[jimg]

yes I know, but why do most on here usually use "wind Force", when they are talking about a "sea state" ?

Because they are confused?

You are right, a lot of UK people link Wind Speed directly to wave height. I think this is because almost every table I have seen listed always list a sea condition next to the Beaufort number.
As we know it is not that simple.

 

[mjf]

F6 will have a different sea state say between Portsmouth harbour, the solent , English channel, bay of biscay etc.

with experience you know what to expect in each place and what part the direction plays too

 

[dt4134]

Hi Bart,

I'm not sure of your point? Most experienced yachtsmen would have a good idea of the sea state given wind speed, duration, fetch, tide, seabed topology etc. It takes an experienced observer to measure significant wave height anyway. Or do you have a means of measuring it on your boat?

There are tables that give wave height given a range of factors. I've never bothered to measure their accuracy. I don't take much notice of any simplified table. It is possible to get a chart of predicted swell height from the NOAA website, but again I rarely bother.

I do log observed wind speed, direction and sea state, but if discussing a trip casually I would usually just mention teh wind speed and perhaps whether it was onshore or offshore.

 

[Nick_H]

Yep, sea state on the 0-9, calm - phenomenal scale is seldom used on its own. I guess because historically the scales have been used by sailors, where wind speed and location gives a better impression of the conditions than sea state alone. ie "we were crossing the channel in a F6 westerley", probably gives the reader more impression of the conditions than, "we were crossing the channel in moderate seas". Wind strength is still important to mobo's, as you well know, so whilst a beaufort wind scale on its own doesn't give the full story, neither does a sea state.

 

[colingr]

yes I know, but why do most on here usually use "wind Force", when they are talking about a "sea state" ?

Ah but that is not quite what you asked.

That is what I interpret F6 as but not all do. As others have said it is probably confused by the descriptions that are usually put against the strengths.

The answer is "It all depends"