Predicting swell

[Rossdoc81]

Im still trying to get all predicting swell thing sorted, Im gettin there but have two questions someone prob knows the answer to

I surfed the right at easkey today(sat) and the peak was shifting all ovet the place. How come some swells it breaks at generally the same spot every wave, and others its all over the shop

If you get a low off the south of greenland how many hours does it take for the swell to travel across the atlantic to Ireland

Thanks

[indoferalbaliboygav]

You need to study the Swell direction and periods more,ER needs a certain direction,with the period that will effect the all over the place stuff,short period means less distance between the waves.
In regards to the amount of time it takes for waves to travel,it all depends on the period or wavelength,higher period swells travel faster than lower period,have read through some of this stuff-

http://www.stormsurf.com/page2/tutorial ... sics.shtml

[CJS]

It's all do with direction of swell and how longer perions will wrap in differently to shorter periods, also there could be more that one swell

Get your hand on a book called surf sience by Tony Blutt also read the below link
http://www.lajollasurf.org/luds.html

These are also good
http://www.wetterzentrale.de/topkarten/fsavneur.html - great for wind click on 10M wind
http://polar.ncep.noaa.gov/waves/
http://polar.ncep.noaa.gov/waves/main_text.html - text tables of swell scroll down to Britsh Isles

[Rossdoc81]

Yeah I read the Tony Butt and thought it was only ok. Maybe im taking a simplified view of it but is this right

East Greenland to the NW is 1200miles
You get a low 200 miles off the E. Greenland Coast
Distance to Ireland is about 1000 miles
Average out the swell period to 12 seconds
Swell with 12 sec period travels 21mph

Distance / swell speed
1000miles / 21mph = 48 hours

So if a low develops off E. Greenland at 3pm fri, turn up on sunday and the swell should pump???

Two days seems too long to me??

Sorry bout the maths lesson but this thing is drivin me mental cos it has to be simple (enough)!

[surfing]

Tony did a few surf prediction tutorials for worldsurfradio.com

[Oisin]

Why bother learning when you can just use a forecast website to do it, and rock up and score when it's pumping?

[surfing]

forecast websites dont always get it right, and allow for local conditions and what you learn - swell, wind, period and tide conditions for spots vary, when you hit a spot thats perfect, its good to be able to file away the setup met conditions that led to that

[CJS]

Why bother learning when you can just use a forecast website to do it, and rock up and score when it's pumping?

Why bother putting any effort in at all - just wear surf gear to be cool

[Rossdoc81]

Don't wanna just rely on surf forecasting, seems to me you can learn way more from the charts and see what size lows in what area of the atlantic give perfect conditions at certain spots.

Also certain predicted swells d'ont show. I use MSW and alot of the swells with small heights and real long periods (like 7ft @ 16secs) never turn up

[Oisin]

Obviously you need to know what conditions work at which spots, but the forecast sites are run by professionals who use algorithms a bit more complex than such and such a period swell takes X hours to hit the coast to come up with their forecasts.
Please tell me if I'm wrong, but surely the charts are drawn using data from offshore buoys, onshore stations, weather baloons, satelites and such and must have a fair bit of joining the dots to cover a whole ocean, which would make them no more reliable than an online forecast derived from the same data.
Taking notes (mental or written) of what the forecasts (or charts) said on the really good days is a pretty solid way to learn what works best where.
If you keep getting skunked I'd ask here, plenty of helpful people to point out why such and such a spot didn't work the other day.
I used the forecast sites yesterday and surfed a head high point on my own for two hours, they work fine for me