h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: How Traditional Weathervanes Work - A737787
Author: Ashley - U276



This is a short, very short, entry on how traditional weathervanes work.

What I would really like, but failed to find, is data that interprets what wind direction actually means.

For instance in the UK a North Easterly wind is a Siberian wind, which means cold weather.

I'd like to include links for as many countries as possible, so it's over to you

Many thanks

Ashley

The site http://www.quibs.co.uk/geography.html gives a list of winds with names (fohn, tramontana, mistral etc), and has the wind directions for a lot of them.

Azara

And the site
http://www.1yachtua.com/Medit-marinas/Mediterranean_Sailing/mediterranean_winds.shtm

gives a nice picture of the directions of Mediterranean winds..

How about a few examples of well-known weather vanes, such as Old Father Time at Lords

Azara,


Thanks for this - I've added those links, that's exactly what I was looking for...

As for images of weathervanes... I may have something up my sleeve.

Ashley,

It's not only the current wind direction that is of interest. By observing the weathervane over a period of time you can tell if a low pressure is passing through, and where.

As general rule, if you stand with your back to the wind and stretch out your arms, the left hand will point to the low pressure zone (in the northern hemisphere). So - if the weather vane shows that the wind is veering (the vane turns clock-wise) or backing then you can work out where the low pressure area is moving from/to.

Our local radio weather announcer is very bad at mis-using "veering". He'll use the term without regard to direction. When I get up in the morning I can't tell if the wind has veered 270 (unlikely) or backed 90

Awu.

P.S. It was my job on a cruise off of the Turkish coast to get the weather forcast every morning. I'd ask the harbour master if we were in a port. The answer was always "Meltemi".

Nice one.

A bit obscure, but that's what we all love most about the Guide eh?

One thing to mention, in the US and especially in Pennsylvania, weather vanes adorn the top of barns.



- Jimi X

Thanks Jimi, I've mentioned barns...

It's amazing, since I wrote this entry, I've noticed weathervanes absolutely everywhere....

in the wind as a tumbleweed threatens to pass this entry by...

I think this is a good entry, although a little short for my liking, I think that if this is all that can be said about the subject, then it is fine. However, do you know anything about the history of the weathervane, as that might be interesting, although it would be going off the subject.

Also, in the section on how they work, you say that
'The inequality of mass mentioned above causes resistance for the oncoming wind and hence forces that section to the back and forces the pointer (the lighter end) to face the wind.' You say that the inequality of mass causes the resistance for the oncoming wind. I would have though there would be resistance even if the masses were equal, but they would roughly cancel each other, or alternately aligh towards and away from the wind, whereas the inequality of masses means the heavier end bears more resistance, so forcing the heavier end away from the wind ,whilst the lighter end has little resistance.

You also refer to 'that section', without telling us which 'that section' is, in the section I quoted above.

Finally, perhaps you should make it clear, at the end of the first section, that the pointer should be pointing towards the lighter end, when talking about the rules governing the upper section.

There's also quite a lot info about winds at A673508 .

I couldn't resist

The North wind doth blow
And we shall have snow
And what will the robin do then,
Poor thing?

He'll sit in the barn
And keep himself warm
And hide his head under his wing,
Poor thing.

There must be a lot more where that came from.

Thanks Guys,

I've made clearer what section I was referring to as it was a little vague to say the least.

I've not mentioned the history of weathervanes as that is the subject of a different entry - any volunteers?


Cheers one and all.

Ashley!