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  1. #1
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    swell period/swell direction

    at how many seconds does a windswell become medium period then long period then groundswell?how accurate are these measurements/forecasts?
    at what angle degree does an east swell become a south swell become etcetera,etcetera,etcetera and how accurate are these forecasts?

  2. #2
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    There used to be a little table explaining the breakdown as definied by Swellinfo, but its not there anymore. The long awaited Tutorials/FAQ will happen sometime soon, I promise!

    short period wind swell < 7.5
    wind swell < 8.5
    medium period swell < 11.5
    ground swell < 16
    long period swell < 17.5
    extra long period swell < 19

    As for directions, there is nothing tricky going on there. There is 360 degrees in a circle, and there are 16 possible swell directions expressed on Swellinfo (N,NNE,NE,ENE,E, etc). So, some quick match tells you the direction N will have 22.5 degrees, so N goes from 347.75 to 12.25. We round to integers, but you can the point.
    Last edited by Swellinfo; Dec 3, 2013 at 04:21 PM. Reason: typo - medium period swell is 11.5, not 10.

  3. #3
    Once you hit anything beyond 13 seconds there are very few places on the east coast that can handle that type of interval. Any regular beach breaks are pretty much walled up closeouts. Forget anything beyond 14, those will be 500 yard closeouts hitting the beach all at once. I don't think I've ever even seen anything around 17-19 seconds here. We do best with medium to lower period groundswells I have found. 9-10 seconds seems to be the best for NJ.

  4. #4
    Quote Originally Posted by stinkbug View Post
    Once you hit anything beyond 13 seconds there are very few places on the east coast that can handle that type of interval. Any regular beach breaks are pretty much walled up closeouts. Forget anything beyond 14, those will be 500 yard closeouts hitting the beach all at once. I don't think I've ever even seen anything around 17-19 seconds here. We do best with medium to lower period groundswells I have found. 9-10 seconds seems to be the best for NJ.
    exactly!!..........

  5. #5
    Join Date
    Jan 2013
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    In the embrace of HIS noodly appendage!
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    Quote Originally Posted by beachbreak View Post
    at how many seconds does a windswell become medium period then long period then groundswell?how accurate are these measurements/forecasts?
    at what angle degree does an east swell become a south swell become etcetera,etcetera,etcetera and how accurate are these forecasts?
    To me whether you call a swell windswell or groundswell, short, medium or long period is all just semantics. It is what it is no matter what term you attach to it. I think the best definition of windswell vs groundswell was posted here in another thread. Basically, if the spot you are surfing is within the fetch that is generating the swell then that is windswell. If you are not in the fetch then it's groundswell. Either way, it's still just a label we attach to it.

    As far as period and what you call it goes, I feel that is relative to where you surf. Most of the waves surfed on the east coast would likely be considered short to medium period if judged by west coast or Hawaii standards. I surf in way south Florida so anything around 8 to 10 seconds might be considered long period. And it's usually windswell too. Still, it's just words.

    Swell direction is easier to define. If it's 90 degrees it's east. 180 is south. 135 is southeast. 112 1/2 is ESE and so on and so on.

    The accuracy of any given forecast is a whole 'nother ball of wax. It will depend upon what a particular forecaster uses for data, (both current and historical), how it interprets that data and applies it to a given location. Where I usually surf is typically difficult to forecast accurately. The wave buoys are a long distance away, the Bahamas shadow mucks things up and winds are often unpredictable. I look at most of the surf predictin' sites along with general weather forecasts to try to develope a consensus as to what might happen. Over time I've learned some of what holds up and what doesn't. Sometimes they get it right and sometimes they miss by a mile. Usually it's somewhere in between.

    This past week had some good examples of the above. On a couple of days everybody missed on the winds. Instead of strong on-shores, we had light off/cross-shores. As a result we had some very clean (by S. Fla standards) and fun waves. Glad I didn't rely only on what was forecast!

    Bottom line, my process for getting some surf: Check the forecasts then the cams, go to my spot(s) and finally get out in the water. Sometimes it's better (or worse) than it looks even from shore. I say, if in doubt, always go out. I have never regretted paddling out for some waves.

  6. #6
    Join Date
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    Quote Originally Posted by Valhalla View Post
    Basically, if the spot you are surfing is within the fetch that is generating the swell then that is windswell. If you are not in the fetch then it's groundswell. Either way, it's still just a label we attach to it.

    I have never regretted paddling out for some waves.
    I like that designation, putting all the numbers aside. Great philosophy on padding out as well.

    I think with all this data we can access it's easy to get caught up in overcomplicating things...

  7. #7
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    Quote Originally Posted by seldom seen View Post
    I like that designation, putting all the numbers aside. Great philosophy on padding out as well.

    I think with all this data we can access it's easy to get caught up in overcomplicating things...
    Yeah, I almost overcomplicated it in trying to simplify it...

  8. #8
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    Quote Originally Posted by seldom seen View Post
    I think with all this data we can access it's easy to get caught up in overcomplicating things...
    that's very true, but knowing the difference between groundswell & windswell is certainly NOT semantics, IMO.

  9. #9
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    Quote Originally Posted by njsurfer42 View Post
    that's very true, but knowing the difference between groundswell & windswell is certainly NOT semantics, IMO.
    Absolutely, agreed...I just feel like lots of dudes get lost in the details w/ this stuff and start to overanalyze. I have a buddy that looks at the animation map(which if I'm not mistaken is based on the same data as the rest of the forecast) and tries to figure the best spot to hit based on the direction in the visual. For me, it's all about what the buoy's doing coupled with wind as I'm leaving the house.

  10. #10
    Join Date
    May 2013
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    Iv read that if the winds creating the waves is more then 100 miles offshore it's a ground swell, less then that and it's a wind swell. Wind or ground swell dosn't matter to me aslong as there are waves. I agree with valhalla though. I'll check the forecasts, then the bouys and the weather for wind. It helps me get an idea of what to expect but nothing is set in stone. More often then not the wind that the weather forecasts and the wind the surf forecasts are two completely different things. Sometimes one is right, sometimes none are right. I drive down to the beach almost every morning. I surf so much more from doing so compared to when I would only go when it's forecasted to be good.

    For example, today was forecasted to be chest high and clean. Tide was high and my go to spots were flat. Checked one last spot, didn't look to good but looked better then others. I paddled out any way, had a blast and surfed for 3 hours. Was only waist high at best but still allot of fun. If I didn't paddle out I would of missed out big time. When in doubt, paddle out. I like that. I'd rather get wet and know for sure it's not happening then to just drive home and possibly miss out.