A real ECL for the long weekend

[barstardos]

If you thought last weekend was a bit blowy, wait til this coming sunday.
GFS is forecasting a trough will approach from the W over Sat and them 'bomb' when it hits the South coast. Looks like a seriously intense system and some good rain. A proper ECL by Ben's earlier definition
The ECMWF does not agree but my guess is its gonna happen.
If you are camping down the coast for the weekend take a 4 season tent and dont pitch it under a tree. Even better, take a 7'4" and stay in a motel.

[thermalben]

Sunday is a little optimistic, IMO. EC is normally a little "fast", and the current model run (12Z Mon) doesn't expect the trough to deepen until Mon next week (suggesting some action Tues thru' Thurs). GFS is even slower than this, and they're both still quite some time away, so I'd be very hesitant to have any confidence in size and/or quality at the moment.

[One Mile Point]

I dont actually want it to be huge, i wnat to be able to surf somewhere this time

[mad]

There has always been something very synonymous between swell events and the June long weekend.

I think Lizzy has a direct line to Huey, a theory which may have a few technical deficiencies, but does help to explain the phenomenum. Bit like Rabbit and the Kirra Pro.

[Nick Carroll]

F**k I hope you're right bastardos, while I have me doubts, I like sloppy 6' waves as much as the next man but 10-12' plus would be a real June treat

Plus my brother's gonna get the swell of the Year in Indo on Sunday and I HAVE to have some kind of lame arse comeback

[thermalben]

EC is going for a peak intensity of 1013hPa (which is actually the climatological MSLP across the globe) on Sunday night before it tracks to the NE. Doesn't look like much of a system IMO.. I'm much more impressed with the prospects of a strong southerly groundswell filling in behind it. Tues could be very good in NSW with light winds and the second half of the south swell.

[thermalben]

There has always been something very synonymous between swell events and the June long weekend

Sounds like the whole "pumping Indo swell on a full moon" thing (both of which are figments of holidaying surfer's imaginations, I reckon).

[Nick Carroll]

Sounds like the whole "pumping Indo swell on a full moon" thing (both of which are figments of holidaying surfer's imaginations, I reckon).

well ben, I think there is a strong argument for tidal magnifying effects on swells in the Indonesian archipelago.

There's a lot of water moving through those islands, particularly through the Bali/Lombok straits, and as we both know, tidal currents can refract swells and cause 'em to do unusual things.

Thus greater tidal movements on the full moon may well help an average ssw groundswell to pull a few special stunts on various reefs. Likewise of course on the new moon, but people don't notice new moons the way they notice fulls (specially when they're sconed on mushrooms).

So perhaps there are grains of truth in this classic surfing "old wive's tale".

That said the three best surfs I've ever had in Indo have been on half moons! Which I put down to little more than coincidence.

[barstardos]

Ben has already mentioned, its not looking like the tight ECL first suggested. More like last weeknd again with a broad Tasman low. This system will cross the Tasman very quickly so the primary swell wont last long but we are looking at a great SSW coming up from the Southern ocean later on. I think you can put the 7'4' away but definetly make sure you got a great tent
Defineitely will continue the Longweekend tradition of appalling weather plus solid (but not huge) surf. I have decades of great memories of Southcoast reefs doing their thing with freezing rain and a gusty SW
Maybe that Queen Lizzie conection is behind the english style weather.

Nick & Ben whats your take on the even older wives tale about "every 7th wave" I think it was poularised in Henri Charriere's escape from Devils Island in "Pappilion"

[thermalben]

well ben, I think there is a strong argument for tidal magnifying effects on swells in the Indonesian archipelago.

Absolutely, I don't doubt that for a second, and am well aware that tides can enhance swells quite nicely. I grew up surfing the Mid Coast in South Australia, and those that have spent time there know that the tide is often the single most important factor when deciding when to surf. The amount of water rushing out of Gulf St Vincent on a dropping tide can completely wipe out a 3' groundswell (the upper limit of the Mid Coast's size range), whilst the Yorke Peninsula and the West Coast see little to no effect at all. Conversely, an incoming tide will often increase wave heights by a magnitude of two or three.

However, when I hear of people booking Indo holidays to coincide with a full moon, purely around the notion that "there will be great waves during a full moon" I really can't see any basis for this. For example, as we're all aware, Indo swells are primarily generated in the Southern Indian Ocean, of which the swell window extends all of the way into the Southern Atlantic Ocean. The travel time (from swell source to destination) can be anywhere from 3 to 12 days, depending on the strength of the weather systems generating the swell (and their geographic position).

Therefore, seeing that the surf we're experiencing on an Indonesian full moon was probably generated at least three days ago, and possibly up to 12 days ago, shouldn't we be finding a correlation between the lunar cycle and the progression of low pressure systems in the two weeks preceeding the full moon? Once you get down to the nitty gritty, it all becomes a little hazy. And with regards to these "great full moon waves", are we looking at what occured during the peak of the lunar cycle, or the "couple of days either side of a high tide"? Suddenly, the error margin starts to widen, throwing a lot of doubt on the credibility of the claim.

I think this theory about there being fantastic waves on a full moon has more to do with the fact that crew are always on holiday in Indo (and not trying to squeeze in a quick session before the arvo NE'er at Narra), so ANY surf is gonna seem bloody amazing. It is a very rare event that anyone *ever* comes home from Indo with surfing tales of woe and gloom. Regardless of the tidal phase.

Same too with the whole Easter/Long Weekend theory. Every single one of my Easter/Long Weekend/Xmas holidays was spent at Yorkes, on the West Coast, down at Portland, over at Bells, etc etc. Of course the waves were going to be much "better" than the local - you have no committments or parents/girlfriends/wives to nag you, you're camping with your mates, and you're surfing fresh and exciting new waves that keep the surfing stoke alive in your belly.

So, based on that - sure, Long Weekend swells are great. But I don't think it'd stack up in New Scientist too well

[thermalben]

Nick & Ben whats your take on the even older wives tale about "every 7th wave" I think it was poularised in Henri Charriere's escape from Devils Island in "Pappilion"

HAHA!! The Gold Coast has barely seen a set with more then three waves in the last two months, let alone seven.

This theory has some basis (statistically), but it's not true in practical applications (ie, don't wait for the seventh wave of the set! Your mates will get a lot more waves than you will). Dr J Floor has written a good summary, with a nice image.

The significant wave height H3 is twice the most probable height and occurs about 15% or once in seven waves, hence the saying "Every seventh wave is highest".

[SAsurfers]

The amount of water rushing out of Gulf St Vincent on a dropping tide can completely wipe out a 3' groundswell (the upper limit of the Mid Coast's size range).

We had 4 foot sets here not long ago

[Dolphin63]

I've heard lots of witchdoctery on full moon swells and new moon swells.
WA's "Camp of the moon" is another place beset by such rumours and it's far from the refractive effects of tidal currents and has a spring tidal range of about 1.5 metres.

There may be something in it though.
One week either side of the full moon and it's a FULL MOON SWELL.
One week either side of the new moon and it's a NEW MOON SWELL.

[Gunther]

What about the saying '1 in every 1000 waves is double the height of the average'...true or not?

I've never believed that

[thermalben]

What about the saying '1 in every 1000 waves is double the height of the average'...true or not?

I've never believed that

I reckon it'd be pretty close. However, what kind of waves are we looking at here? Swell or surf? A trace from one of the waverider buoys shows that this isn't too far off for "swell" waves (ie out at sea, not on the beach). Take a look at Sydney - Hsig (significant wave height) is 1.3m, whilst Hmax (maximum wave height) is 2.2m (actual numerical values obtained from Weatherzone).

We can already see that "maximum" wave heights are nearly double that of "significant" wave heights. However, the definition of "significant" wave heights is "the average of the highest 1/3 of all recorded waves" (over a 26min time frame). If you were to take the average of ALL waves, this figure would drop a little more, depending on the percentage of windswell and groundswell in the water (probably only a small amount today due to the light synoptic wind).

So, lets suggest that the "average" wave height is 15% smaller than the significant wave height - this results in an average wave height of 1.105m.

If we then take 1.105m to be an inferred "average" wave height, doubling it gives us 2.21m - just a shade larger than the maximum recorded wave height of 2.2m.

[scroopulis]

Blimey....


Thermalben, what is the meaning of life?

(love your work)

[mad]

TB wrote

So, based on that - sure, Long Weekend swells are great. But I don't think it'd stack up in New Scientist too well

Under estimate the power of Lizzie at your own peril. She has a direct line to Huey. It's true, I read it in New Idea, much more cred than New Scientist.

Talking about old wives/surfers tales a mate and I planned a surf trip to New Cal based around the surf turning on during the winter solstice based on stories passed on. Admittedly had good waves pretty much all trip, but the solstice cranked.