Where did you surf today ?

[steve shearer]

Kj from Surf-forecast for Lennox today were 153-108-75.

So Cranked, you're suggesting that has about as much energy as low period windswell from the Gulf of Thailand?

What do those numbers mean to you?

[foamy]

All Cranked has said is that he knows what it means for his preferred break on the Bukit and he finds it, from long experience, a reliable guide there.

[steve shearer]

I'm trying to get a sense of what it is measuring though, to see how it can be extrapolated to other breaks.

I check (and surf) several breaks daily, as well as rockfish.

If I can understand what it is measuring in terms of observations- I can start to calibrate it for various breaks.

Maybe it just doesn't work for the East Coast, if not, why?

Waves are similar emergent phenomenon wherever they break.

If kJ only applies to the Bukit why do they include it for all their global forecasts?

[steve shearer]

So Cranked, what do these figures indicate for you?

153-108-75

[Cranked]

Umm... phone number?

[Cranked]

I'm trying to get a sense of what it is measuring though, to see how it can be extrapolated to other breaks.

I check (and surf) several breaks daily, as well as rockfish.

If I can understand what it is measuring in terms of observations- I can start to calibrate it for various breaks.

Maybe it just doesn't work for the East Coast, if not, why?

Waves are similar emergent phenomenon wherever they break.

If kJ only applies to the Bukit why do they include it for all their global forecasts?

It's a generic measure of energy, waves are moving water.

A joule is the amount of energy needed to exert a force of one newton through one meter. For example, if you lift a one-kilogram weight one meter, then the energy you must expend is: E = Fd = (ma)d = mgd = (1 kg)(9.8m/s2)(1 m) = 9.8 kg m/s2 = 9.8 joules.

[Cranked]

I remember the big swell that hit Ulus about 5 years ago. It was magnificent, at 30,000kJ.

What a magnificent number, an incredible amount expended by each wave. Today was 4,000kJ.

Wave height is a very bad measure of a wave, it's a linear measure of what is in fact an order of magnitude phenomena, kJs report what is the main characteristic of a wave, its energy.

[Cranked]

You only have to check your local Steve, Surf Forcast was calling Lennox Head around 110kJ today and predicting around 170kJ tomorrow.

Oh, I just realised you did just that, your numbers, 153-108-75, were your local kJs!

So yeah, that means waves of a foot or two, suitable for a mal

[Pants]

I remember the big swell that hit Ulus about 5 years ago. It was magnificent, at 30,000kJ.

What a magnificent number, an incredible amount expended by each wave. Today was 4,000kJ.

Wave height is a very bad measure of a wave, it's a linear measure of what is in fact an order of magnitude phenomena, kJs report what is the main characteristic of a wave, its energy.

Did you put weight on? That’s the macaroni and cheese of swells.

[buddy]

And today, the skull candy groms and Dads discovered Ballina.
Been empty all week.
Got a few before the rush.

[steve shearer]

It's a herd mentality- easy enough to duck and weave.

[Beanpole]

I'm trying to get a sense of what it is measuring though, to see how it can be extrapolated to other breaks.

I check (and surf) several breaks daily, as well as rockfish.

If I can understand what it is measuring in terms of observations- I can start to calibrate it for various breaks.

Maybe it just doesn't work for the East Coast, if not, why?

Waves are similar emergent phenomenon wherever they break.

If kJ only applies to the Bukit why do they include it for all their global forecasts?

It's a generic measure of energy, waves are moving water.

A joule is the amount of energy needed to exert a force of one newton through one meter. For example, if you lift a one-kilogram weight one meter, then the energy you must expend is: E = Fd = (ma)d = mgd = (1 kg)(9.8m/s2)(1 m) = 9.8 kg m/s2 = 9.8 joules.

Well that clears that up

[steve shearer]

Oh, I just realised you did just that, your numbers, 153-108-75, were your local kJs!

So yeah, that means waves of a foot or two, suitable for a mal

OK, finally we are getting somewhere.

Surf yesterday for Lennox with those numbers.

Inconsistent long period sets to 3ft (OH) through the morning.

Strong pulse of S/SE groundswell (well OH) (15-16 second periods) in the a'noon.

OK, so maybe Surf-forecast algorithm just can't resolve East coast swells?

I've been trying for a while now to match it to local conditions and it bears absolutely no relation to reality.

[buddy]

Oh, I just realised you did just that, your numbers, 153-108-75, were your local kJs!

So yeah, that means waves of a foot or two, suitable for a mal

OK, finally we are getting somewhere.

Surf yesterday for Lennox with those numbers.

Inconsistent long period sets to 3ft (OH) through the morning.

Strong pulse of S/SE groundswell (well OH) (15-16 second periods) in the a'noon.

OK, so maybe Surf-forecast algorithm just can't resolve East coast swells?

I've been trying for a while now to match it to local conditions and it bears absolutely no relation to reality.

Does the wide swell angle and often overlaying swells stuff it up which say, southern and Western Australia and Indo don’t have as much?

[steve shearer]

Yeah, I think so.

Much more complicated and complex swell window.

[Cranked]

Most probably Surf Forecast uses the most relevant wave buoy data to generate the kJ forecasts (or maybe its part of the buoy data anyway).

That wouldn't work for longer forecast periods though, so they must also be using other generic data sources (that Steve would know off the top of his head). It's definitely done by algorithicly manipulating generic data sources though, as there is no way human input could work for the hundreds of locations around the world that Surf Forecast covers.

So the accuracy is dependant on the location of the nearest buoy?

[alakaboo]

Not the nearest.
Think about where your swells are coming from cranked.

[Beanpole]

Heaps of waves today and heaps of burns.