swell direction?

• Mar 15, 2008, 07:39 PM
pawley
swell direction?
i understand how the whole swell direction by degree works i just don't have a chart or reference to fully understand what direction a particular swell is coming from. can someone help me with where to find this info?
• Mar 15, 2008, 09:49 PM
dirtyhairy130
Some great info on magic seaweed on swell dynamics: http://magicseaweed.com/content/surf-forecasting.php

Check out the article on swell propigation, I think it deals with your questions.

As far as finding out the direction a swell is coming from just look at the "swell plots" under the "time plots" tab. Swellinfo does not give degrees for the swells but uses direction instead(N,S,E,W,etc.), but they are referring to the same thing.

Surfline also has some good detail about swell direction. If you go to the forecast dashboard and click on offshore swells you get the direction in degrees for all swells in the water along with the range of degrees the swell will come in from( the +/- measurement).

Its important to note that swells acually come in from a range or directions. The degree measurement we see on the forecast page is simply the mean swell angle. Swells coming from a close by storm (wind swell) will have a high range of degrees, swells generated from far away will typically have less variation in their direction. It appears that this number is roughly correlated with period. This is an important reason why short period swells are disorganized and inconsistant. Ex: your surfing an east facing break on a short period SSW swell(like the ones we have been seeing around here lately). The direction may be at about +/- 25 degees, so the set waves we see breaking on the beach can actually the ones that are coming from S or even SSE.

hope that helps.
• Mar 15, 2008, 10:04 PM
Swellinfo
Quote:

Originally Posted by dirtyhairy130
Its important to note that swells acually come in from a range or directions. The degree measurement we see on the forecast page is simply the mean swell angle. Swells coming from a close by storm (wind swell) will have a high range of degrees, swells generated from far away will typically have less variation in their direction. It appears that this number is roughly correlated with period. This is an important reason why short period swells are disorganized and inconsistant. Ex: your surfing an east facing break on a short period SSW swell(like the ones we have been seeing around here lately). The direction may be at about +/- 25 degees, so the set waves we see breaking on the beach can actually the ones that are coming from S or even SSE.

hope that helps.

Well said, Also by looking at the wave maps, using the white arrows, you can see graphically the mean swell direction.
• Mar 16, 2008, 01:29 PM
pawley
thanks for the help guys. the info on seaweed is great. i don't know why i've never noticed it before as i check theat site faily often. so what are your thoughts on this upcoming swell? i can't remember a forecasted swell wtih this much organization in some time.

and btw.. why no nor'easters anymore. i recall as a kid having them all the time. i can't even remember the last one!
• Mar 18, 2008, 05:47 PM
eisurfshop
If you’re lucky, you may have a directional wave gauge in your area that can help you differentiate all the different seas or swells that are in the water in real time (periods and relative “spread”) . We’re very fortunate enough to have one just 1,000 feet south of Bogue Inlet Pier here in Emerald Isle, NC. The link for this is http://nccoos.org/platforms/piers/bo...t-fishing-pier. The “cheat sheet” located at the upper right will help decipher all the squiggly lines. We check this site religiously several times a day and use the information in our morning surf reports. Hope there is one (wave gauge) further south closer to you. Cheers. – EI Surf Shop
• Mar 18, 2008, 08:46 PM
pawley
that is totally what i was looking for. man i love a good cheat sheet! thanks for sharing the info.