Cape Town Basic Rules

[Toby]

Same same. In Germany I rode pretty similar water conditions, but has more power windwise.

Hmm... But what else could it be? It can't be temperature. I ride in Germany. Now we have ~ -5°C in summer we have up to 30°C and I never felt a noticeable difference from ~30 degrees difference in temperature, at the same spot.

Yes, I have some thermal spots up high in the mountains which feel different. Thermal winds are very different at that spot: airspeed is often higher close to the water and get's slower more upward.

So maybe the wind is 20knot at the ground but a lot higher ~5m above ground?

- Oliver

maybe, I just don't know. Brazil has normal wind plus thermal...therefore it gets stronger. But look at the BAKL Brazil and compare to CT videos from the lagoon they ride in...there it is always higher. We should ask one of those riders what difference they feel.

[Jan:)]

If you try to get maximum height, the more gusty it is, the better.
If you have 20 Kn average wind, switching between long periods of 17kn and gusts of 26kn, you will jump much higher than constant 20kn.

CT has super gusty wind, brasil has extremely constant wind.
So that matches my expectation.

[Peter_Frank]

Hmmm, this is involving into some, IMO, wrong assumptions now.

I could be wrong, but my take on this is:

No, it is not about wind density, typically really warm 25-40 degree celcius air in CT.
Current not an issue, and if, it goes downwind often so thats not it.

Water conditions, naaah, doesnt matter in my experience and what I see.

BUT, for one, when you rig a kite in CT, to fit the wind, the wind almost always without exception, picks up.
In fact the most normal scenario (but with a few exceptions, it can kick in earlier) is, no wind early, and around 14 o'clock wind kicks in.
And it just accelerates all day, till even after sunset.

Meaning, this fact alone, I believe is one of the reasons why wind feels SO much harder in CT.

The other thing is, there could be at least two additionals facts in play.
Wind measured right at the coast, all weather stations even if up high, will have less wind than a bit further from the coast.
We all know this, and a lovely thing, as when riding waves close to shore you are perfectly powered, and when going upwind further out, you can go much faster upwind because you are almost overpowered.

Also, there is a good chance the wind gradient can be different, so a more pronounced wind gradient, combined with quite some more wind as soon as you leave the beach - is my shot on why 20 knots in CT feels like a lot more, apart from the obvious if you have ever been there, that the wind accelerates all day, so wind is higher when you are out on the water, no matter which size you rigged for.

My take on why 20 knots feels like a lot more than 20 in CapeTown

And it does, believe me (and everybody else riding there)

Peter

[Toby]

Once someone said it’s the difference in air temp to water temp in CT that makes the wind stronger somehow.

Not sure, anyone knows more about it ?

[Peter_Frank]

Once someone said it’s the difference in air temp to water temp in CT that makes the wind stronger somehow.

Not sure, anyone knows more about it ?

You are right Toby, the wave and air temperature difference is huge, compared to other spots.
So would be an obvious thought.

But I honestly dont think it matters in respect to air "power".

Wind is sideshore, actually often a tad offshore but guided sideshore by the coast - which means the wind can be a lot stronger just a tad out.

I really think this is the main reason, besides the fact the wind usually keeps increasing all day, why everybody without exception find there is more wind and power in CapeTown wind

Peter

[dracop]

Wind in Cape Town has alot more push than same speed wind elsewhere.

Air density is very high compared to other locations. Keep in mind the kite canopies are made of fabric - once the gaps in the fabric are saturated the rest of the wind is going to push the fabric wind trap much harder as it has nowhere else to go. The canopies are air proof - air does flow thru the gaps in the fabric.

30 kts in CPT feels really strong compared to 30 kts in most tropical destinations and you can jumo much higher. Take a trip there and find out the reality of it.

[Peter_Frank]

Wind in Cape Town has alot more push than same speed wind elsewhere.

Air density is very high compared to other locations. Keep in mind the kite canopies are made of fabric - once the gaps in the fabric are saturated the rest of the wind is going to push the fabric wind trap much harder as it has nowhere else to go. The canopies are air proof - air does flow thru the gaps in the fabric.

30 kts in CPT feels really strong compared to 30 kts in most tropical destinations and you can jumo much higher. Take a trip there and find out the reality of it.

Sorry, I dont think this is correct, that air density is higher.
I am with Sarda on this one, physical facts. And jedi1.


Air density is solely determined by barometric pressure, air temperature, and humidity.

We are at sea level and right now pressure is "standard" around 1013, so thats not it.
Humidity is typically around 70 % in Capetown, which means density is 1 % less than dry air (dry air has the highest density), so thats not it.
Air temperature is most often between 20 and 30 degree celcius, eventhough the water is maybe only 14-15 degree.
I often ride in shorts, and usually shorty, not possible if air was as cold as the water, so thats not it.

Then we have the well known phenomenon "cheese wind", small holes in the wind can make strong wind have very little power.
But as many experience the opposite on their local spots in other countries, "Perfect" wind, typically in onshore seabreezes or similar, where the felt power in the wind is a lot stronger than the actual windspeed - it would make CapeTown wind feel less strong - so thats not it.


I still believe it is the 3 factors, wind increasing over the whole day plays a trick with our minds, and then both vertical and horizontal higher wind gradient.

In particular the vertical wind gradient, will make your jumps even higher, besides gusts which can "rocket" you up - a perfect combination for high jumps

Peter

[Van Hunk]

Hmmm, this is involving into some, IMO, wrong assumptions now.

I could be wrong, but my take on this is:

No, it is not about wind density, typically really warm 25-40 degree celcius air in CT.
Current not an issue, and if, it goes downwind often so thats not it.

Water conditions, naaah, doesnt matter in my experience and what I see.

BUT, for one, when you rig a kite in CT, to fit the wind, the wind almost always without exception, picks up.
In fact the most normal scenario (but with a few exceptions, it can kick in earlier) is, no wind early, and around 14 o'clock wind kicks in.
And it just accelerates all day, till even after sunset.

Meaning, this fact alone, I believe is one of the reasons why wind feels SO much harder in CT.

The other thing is, there could be at least two additionals facts in play.
Wind measured right at the coast, all weather stations even if up high, will have less wind than a bit further from the coast.
We all know this, and a lovely thing, as when riding waves close to shore you are perfectly powered, and when going upwind further out, you can go much faster upwind because you are almost overpowered.

Also, there is a good chance the wind gradient can be different, so a more pronounced wind gradient, combined with quite some more wind as soon as you leave the beach - is my shot on why 20 knots in CT feels like a lot more, apart from the obvious if you have ever been there, that the wind accelerates all day, so wind is higher when you are out on the water, no matter which size you rigged for.

My take on why 20 knots feels like a lot more than 20 in CapeTown

And it does, believe me (and everybody else riding there)

Peter

Excellent summary Peter. Combine this with at time pretty gnarly swell and crowds and you get what you get.

[Jan:)]

Honestly I do not know how you would even measure windspeed somewhat accurately at any of the CT spots.

[Sarda]

Any Southern African person who went to a reasonable school and paid attention in geography should be able to (partly/time) recall that the predominant wind over the Cape Peninsula the SE trade from anticyclones in the Southern ocean?

It meets the Westerlies which split at the Cape Peninsula and becomes the "re-curved" (I cant remember) branching North past Namibia and the SE trades?

Imagine the splitting of a large airmass where it meets another large airmass?

The overwhelming importance being, when it meets with the ITCZ and another wind I cannot recall from the N East/erly monsoon , it provides the rainfall for a large part/most of Southern Africa which sustains the living conditions there?

Hence its importance.

Focus on the 2 large air masses meeting and one of them splitting, all at the Cape Peninsula and that might help you?

Or some crap like that?

Focus.

Guessing what the weather is doing is about as much use as guessing what size kite to use?
Trial and error often ends up being just that?