A question of wind

[ShakyBake]

Due to some confusion over a quiz tonight I wondered if a tone could clarify please:

If there is a South Westerly Wind, does that mean it is blowing from or to that direction?

This is a very interesting question. I’m hanging around.

Blowing from

Where the wind is coming FROM.

From

Wouldn’t a south westerly wind be FROM the south west? And therefore warmer than a northerly wind?

Hence why the North Wind is always perceived as cold, that’s how I remember it.

From. It means the wind is blowing FROM the south west.

wind is always stated from the source not the destination, so a South Westerly Wind means it is coming from the South West (hence probably warm) as opposed to a North Easterly which is blimmin' freezing 😆

Thank you very much, makes sense

It's labelled where it's from because that's what's important - where it's from tells you if it'll be cold or smelly or dusty etc. But it's confusing because it's not where the weather vane points - edit, hang on i think I confused myself there with the double negative. So the weather vane arrow bit points towards where the wind is coming from, not the way the wind is going to. Edit again - unlike a windsock.

Basically op, don't feel bad about being confused about this, I do actually know the answer and still couldn't explain it right. It's not instinctive, especially weathervanes

And … the prevailing weather in the UK is FROM the south west. The mighty Atlantic Ocean drives a lot of our wind & weather. Local hills & valleys can make the local direction change but it mostly comes in off the ocean.

Google:
“ … meteorologists around the world name winds by the compass direction from which they blow (e.g., a "west wind" comes from the west and travels east). This convention is standard globally across science, aviation, and weather reporting, though local names may also describe specific regional weather events.”

"It's confusing because it's not where the weather vane points*

I think it depends on the design of the vane.

Proper old fashioned style ones pivoted in the middle, pointed at one end, broader at the other should swing so the point is into wind,.broad end downwind.

Some of the more modern ones don't have the pointed end so pivot broad end downwind... so yes, there's maybe scope for confusion..

ETA just seen the edit, we're in agreement.

But yep, whether it's referenced to a cardinal point (e.g. westerly) or a bearing (e.g. 270 degrees) it's always direction it's blowing from.

So it's not actually the ocean that drives the prevailing winds, you get them over land just the same (eg above Asia). They're driven by the rotation of the earth and conservation of angular momentum (otherwise known as the Coriolis force).

Briefly...The ground is moving faster at the equator as it's further from the axis of rotation (imagine a spinning top). If air moves northwards, it is now going from west to east faster than the land.

Umm, I'm really not sure about that model.

A lot of air movement (wind) is intially down to pressure difference/ and or temperature differences..

Coriolis really comes into explaining why the air,.once it is moving ends up travelling in the direction it does - e.g. the direction of flow around a depression verses an anti-cyclone.

That's about as far as my aviation met safely takes me so I'll stop digging and wait for a Met person to stop by

Ah I didn't know that modern weather vanes don't have an arrow. But yes either way, the sort of pointy end points towards where the wind is coming from, and also its name eg westerly.

Windsocks do the opposite i believe, as do flags, and other DIY tricks like when golfers drop sand (the sand goes the way the wind is going to, not from).

I guess you could argue that, in golf or sailing, you might prefer to know where the wind is going to. Hence windsock on the beach or flag on a golf course. In everyday type decisions (what to wear etc) you'd rather know where it's coming from, hence weather vane on a town hall etc

You are talking about everyday winds. Pp and I are talking about the prevailing winds, which is something very specific. This is something I studied.

Edit again - please do read about this, I think you would be interested. The rotation of the earth does not just drive localised cyclones, it drives the entire prevailing wind vs trade wind motion around the globe.

I need help understanding the second half of this thread…

You can do a simple Google "how does the coriolis force cause the prevailing winds and trade winds" or "how does conservation of angular momentum explain the prevailing winds".

It is a sort of old wives tale myth that the Atlantic drives them - only Europeans would think this because the Atlantic is to the west of us. But they circle the globe in both hemispheres

On the basis of having studied and actually for a time taught basic Met a bit of over the years (aviation context) I take your point but reckon you're brave bringing Coriolis in so early...it's.in there but so are pressure gradients and thermal gradients,.both at a local and on a global scale...it almost ends up chicken and egg.

.

.

The north wind doth blow,
And we shall have snow,
And what will poor robin do then, poor thing?
He'll sit in a barn,
And keep himself warm,
And hide his head under his wing, poor thing.

North is definitely cold! 🥶

This thread has highlighted to me how very little I know about weather.

Jeez I thought this thread was going to be the answer to my significant flatulence problem…

Ah, there's the old joke that combines your problem, a visit to the Doctor and the actual subject of the thread......

Can’t decide if this is a thread about the weather or a round of Mornington Crescent…….

That poster was talking about prevailing winds being driven by an ocean and I just wanted to correct him/her of a common/ancient misconception... no doubt you have the same motivation to reply to me, but you misunderstood my comment as being about all weather and/or you are not aware of "prevailing" having a very specific meaning in this context. Because the prevailing winds are very much not driven by temperature or pressure gradients. That is why they are called "prevailing".