Wind Arrow/Vector Direction Conventions

[Mark-1]

There are two ways in which a wind arrow/vector vector can be drawn.

1) Arrow pointing in the direction with wind is coming from. ie Arrow points N for Nly wind. (See Chimet.)

2) Arrow pointing in the direction of the flow of wind, ie with the wind, like a wind barb (ie Arrow points S for a Nly wind). (See BBC/Windguru's Meteograms.)

Do the two wind arrow conventions have names?

 

[LadyInBed]

Right and Wrong?

 

[Poignard]

Wrong and right

 

[Mark-1]

Consulting Google, I reckon 1) could be described as indicating Wind Vector Azimuth & 2) could be described as indicating Meteorological Wind Direction.

Any advance on that?

 

[RichardS]

Consulting Google, I reckon 1) could be described as indicating Wind Vector Azimuth & 2) could be described as indicating Meteorological Wind Direction.

Any advance on that?

What practical use is 1) ?

Richard

 

[Mark-1]

What practical use is 1) ?

Richard

Usefulness is subjective, obviously it's what a wind instrument with a dial does.

 

[LadyInBed]

Sounds like a recipe for confusion!
I've always understood that wind is always described as from (as per Shipping Forcast) (and current is always described as going (to)).

 

[RichardS]

Usefulness is subjective, obviously it's what a wind instrument with a dial does.

That's a good point Mark.

When I set off on my boat after the 6 months lay-up for Winter, the first time I look at my wind indicator (the electronic dial not the masthead instrument) I stare at it for a few seconds and think "Is it pointing into the wind or away from the wind". I then feel the wind on my face and it's clear that the sharp end of the needle is pointing into the wind and then I'm sorted for the rest of the season.

I thought about this once and decided that what Raymarine should have is a pointer like an arrow -----------> but with the chevron part above the spindle in the middle of the dial. It would then be clearer (I think?) that arrow is showing the wind direction.

But then I'm probably the only one who gets befuddled about this. :ambivalence:

Richard

 

[nigelmercier]

... obviously it's what a wind instrument with a dial does.

Laalaalaalllaaa! I can't hear you. I don't want to think about that.

 

[DJE]

What practical use is 1) ?

Just historically it's always been much easier to make a weathercock that well weathercocks.

 

[RichardS]

Just historically it's always been much easier to make a weathercock that well weathercocks.

But why would it be and harder to put the vane on the cross-piece with the arrow to leeward of the vane:

''''''''''''''''''''''''''[XXX]
---------------------->>


There you go .... a true wind direction weather cock!

Richard

 

[DJE]

But why would it be and harder to put the vane on the cross-piece with the arrow to leeward of the vane:

Balance?

Edit:-

Maybe not so hard after all!

 

[RichardS]

Balance?

Ah yes .... but check the cross-piece on my design and you will see that the section of cross-piece to windward of the pivot point is thicker and heavier than the leeward section!

(After 50 years of engineering experience you'll have to be very sharp to catch this old dog out! )

Richard

 

[DJE]

Ah yes .... but check the cross-piece on my design and you will see that the section of cross-piece to windward of the pivot point is thicker and heavier than the leeward section!

(After 50 years of engineering experience you'll have to be very sharp to catch this old dog out! )

Richard

Of course - the old depleted uranium counterweight!

 

[RichardS]

Of course - the old depleted uranium counterweight!

Oh hell ...... I forgot to deplete it on my prototype. :ambivalence:

Richard

 

[snowleopard]

This avoids confusion:

 

[{151760}]

Regardless of whether the vane (virtual or real) points North or South, we all agree that that's a northerly wind, and as Sod's Law says it will be bang on the nose most of the time, why worry?

 

[Mister E]

If the rest of the word has the arrow pointing towards where the wind is coming from. Then obviously sailors must have the arrow pointing in the opposite direction.
Those pesky landlubbers can not be right

 

[davidej]

If the rest of the word has the arrow pointing towards where the wind is coming from. Then obviously sailors must have the arrow pointing in the opposite direction.
Those pesky landlubbers can not be right

Sounds a bit like the recent thread on whether French time is UT plus one or minus one.

The upshot of that seemed to be that sailors do it one way and the other 7 billion inhabitants of the earth do it the other.

 

[Mister E]

Sounds a bit like the recent thread on whether French time is UT plus one or minus one.

The upshot of that seemed to be that sailors do it one way and the other 7 billion inhabitants of the earth do it the other.

Can make for some good entertainment even if we do not understand the replies.