Micah, What is this talk about a strong system in the deep south atlantic possibly sending us loooooooooong period ground swell for august 16- ?? . LOLA models calling 17 sec + stuff. Your thoughts?
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Thread: South Atlantic Storm...
Aug 9, 2007, 04:52 PM #1Junior Member
- Join Date
- Sep 2006
South Atlantic Storm...
this happened earlier in the summer from the equatorial Atlantic activity, but its usually not anything major that makes it up our way.
Take a look at the Swellinfo North Atlantic wave maps, you'll notice a little blob tracking towards the windward islands... Lets hope we get some development here...
this may have been the woooorst summer everrrrrrrr. . .three weeks left for redemption but i'm really banking on september and october, those lp groundswells are fickle anyway need real medium period head high juice that has actual sets insted of the crap we've been getting
Yeah 17-18 sec. swells are no good in DE/MD most of the time, especially when they are a little bigger. Sometimes a small long period swell is really fun though. Normally, a big 10-11 sec. ESE or SSE swell is best.
Aug 10, 2007, 02:09 PM #5Senior Member
- Join Date
- May 2006
- Baltimore, MD
I'm going to take a stab at this one...(micah, if this is wrong please correct me) but i believe it has to do with the depth of the ocean off of the east coast. Long period waves tend to reach deeper into the ocean and therefore the continental shelf will have a more profound impact on the wave height that on our typical short period swells. Friction causes the wave to lose energy and thus lose it's height
If you look at our friends in Cali, they have little to no continental shelf off the coast (blacks for example has a giant canyon) so when they get a long period swell the bottom will not cause the waves to shrink significantly.
Generally speaking, depending how wide and how long the fetch is that generates these waves you can expect the energy to dissipate as it moves away from the storm.
Also worth mentioning is that the sand on the east coast tends to be setup better for short period swells and can't handle the amount of energy a long period swell brings to the coast. Of course you also need to account for how the wave refracts off of inlets, piers, etc...but i think you get the idea.
There is a good basic book out there called Surf Science by Tony Butt. It covers how to forecast waves in easily understandable terms. I read it every time i take a crap...haha.
Last edited by beaner; Aug 10, 2007 at 03:02 PM.
Aug 10, 2007, 03:01 PM #7
sure thing... Here's a simplified answer:
This is what I call CS syndrome or continental shelf syndrome.
On the east coast, the continental shelf extends far off the coastline, as compared to the west coast or the island chains (which don't have a shelf).
The longer the period of the swell, the deeper the swells reach underneath the ocean surface. So, when you have long period swells, the shallower water due to the wide east coast continental shelf acts to dissipate the swell energy offshore.
Of course, the water depths vary all along the coast, so some areas can handle the longer period swells more than others. Also, when you have long period swells, wave refraction plays a much bigger role, and the wave heights can vary tremendously between different breaks. You'll notice out in SoCal, there is lots of variability between breaks.
For the Mid Atlantic area, I'd say swell periods between 9-12 seconds are optimal. Because of the CS syndrome, and also longer period swells tend to just create close outs on our average beach breaks. Further north, in New England, there are more headlands that can refract the longer period swells into nice point break stuff.
closes out at my beach, too walled, long wait between sets, inconsistent, really sensitive to tide, etc it'd be good if we had pointbreaks
Aug 10, 2007, 08:09 PM #9Senior Member
- Join Date
- Jan 2007
Aug 9, 2007, 08:09 PM #10
The past few years, its been like GOD turned on a switch on September 1st...
august can go either way, but the past few august seasons haven't been too good.