forcast time plot??

the seconds measure the amount of time it takes for 1 wave to pass from crest to crest

A longer period means the wave has more energy, and also means it has probably come from much further away (aka groundswell)

A shorter period has less energy, and comes from a more local source... aka windswell.

Generally, we want groundswell over windswell, because its more organized and has more power and "oomph" when your riding it. But it also just depends on your local break and how different periods and directions effect it.


there are numerous other posts about this.... also check out http://www.surfline.com/surfology/surfology_forecast2.cfm

 

The seconds (wave period) also relates to the size of the wave face height.

For example, at an average beach break:
4 ft @ 6 seconds might be 2-4ft wave face.
4 ft @ 12 seconds might be 4-5ft wave face.

So, when you see the surf timeline shows around chest high, you can scroll over to find out the swell height and swell period in which that chest high calculation was made from.

 

yeah, shorter period usually equals less time between sets, but i believe there are other factors too

 

yes, the wave period is the time between sets.

But, keep in mind, the period that is reported is the dominant period of a particular swell or of the overall significant wave height. So, if the swell period is 12 seconds, that doesn't mean there isn't other swells in the water with different swell periods. At any time, there are waves approaching a particular location from all over the Ocean. We use statistical approaches to categorize the waves into dominant swells groups, which we report - such as 3.5 ft ESE swell @ 10 seconds. I hope that makes sense.

 

5ft at 2 seconds is not waves, its just repeated windchop breaking on top of itself with no organization whatsoever... they really start recording ridable windswell at about 6-7 seconds, if I remember correctly. 5ft at 35 seconds, that is a good question, I have never seen conditions like that. Usually the best groundswells that are huge are like 10-15ft at 18 seconds or something along those lines...
During the Tsunami, I heard reports of 4ft at @ 3 minute intervals...... I guess that fact that tsunami water can reach upwards of 400MPH, that what the 3 minutes means.... The size was still 4 feet, but when each wave arrived at certain points, it was a traveling 4 ft wall of disaster... I think anyway...

 

if you think about it.... our tides are really just 4-6 foot waves circling the earth with a 6 hour period

 

I hate to say it but around hear in Maryland, many of the days that have been the most fun have been short period windswell with some size. I have seen long period swell with size that was very good but have seen more of those days maxing out the sand bars with lots of closeouts. Give me a sizable south windswell in the summer anytime over a macking hurricane groundswell for pure fun. I do like smaller groundswell with a steep south angle though.

 

ocean wind produced waves are 24 seconds or less.

And, in the Atlantic, even on large Hurricane swells or the rare South Atlantic swells are 17 to 19 seconds max. The pacific allows for greater fetches and greater distances for swells to travel, and can thus have swell periods of up to 20 seconds and greater.

When you talk about non wind produced waves, such as tides, and tsunamis, then you can talk about periods greater than 30 seconds.

 

yup.. that's why when it's borderline surfable (small) incoming mid tide is always best.

 

5ft @ 2 sec would probably be building storm surf

5ft @ 35 seconds wouldn't happen

 

have you read waves and beaches? i'm reading it and i swear you're quoting it word for word ha

 

no, i have not read that book.

 

He hasn't read it because... he wrote it.

 

One more thing about period...this was partially implied already, but the longer the period the faster each wave moves. The shorter the period the slower it moves. By moves, I mean the velocity each wave travels toward shore. So part of the reason a longer period wave has more "power and oomph" (as mentioned earlier) is because it is actually moving faster.

The reason those big groundswell days feel like your paddle is having a hard time keeping up with the wave, is because it really is. If you've ever traveled to a break that gets that kind of swell (for example Pacific spots), you have felt this; the whole ocean FEELS different than our east coast breaks.

Also, the leading edge of a long period groundswell will have a longer period and will be moving faster. They're called forerunners. Once the groundswell event has hit and is in mid-stage, the period will drop a bit, although it can still be very good.