Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.
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| Source: MagicSeaWeed.com. |
Expect a 3 - 4 foot surf tomorrow with the possibility of a bigger surf next weekend. While the surf is not very big, it will be supplemented by a pretty big high tide.
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| Source: nhc.noaa.gov. |
As you can see, there are a couple areas out there to watch. While they aren't expected to become hutticanes, they could affect our surf.
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On 9/17 I did an introductory post on predicting beach erosion. I talked in general terms, even though there are many variables to consider. When you talk about beach erosion, you have to remember that every beach will not be the same and erosion can be scattered. Some places will be eroded while others are not.
Add to that the fact that not all erosion is not the same. Some will not be deep enough or in a location that will be productive. Erosion in replenishment sand, as we recently saw, is not the kind of erosion that people hunting old shipwreck coins are looking for. So erosion varies in its amount, consistency, and how well it is placed.
Yesterday I gave some generalities, and perhaps should have been more precise, but I did what I could in a short post, so today I'll try to clear up some possible questions.
Above you'll see an illustration showing a curved beach and three different directions that the waves might come from. I'll ignore for the present that you can have a secondary as well as a primary swell. And I'll also simply mention that the wind direction and direction of the swells are related to some extent, but not perfectly.
For present purposed I'll discuss two factors - the shoreline and the direction of the swells.
Maybe you noticed times in the last couple of years when Treasure Coast beaches eroded before the big surf arrived. I've seen multiple occasions in the last couple of years when a front came through, as they often do from the northwest, and the beaches eroded the day before the higher surf began.
So why would a northwest wind cause erosion? As I said, for now I'll ignore the imperfect relationship between the wind and wave directions. Look at the illustration above.
The Treasure Coast beaches do not run, for the most part, exactly north to south. It mostly slants from a bit from northwest to the southeast. Therefore, when the water hits from the northwest (NNW), it would slice into the beach at an angle that would cause erosion where the beach is angled as shown at that point of the illustration. The same wind/water direction would not cause erosion below the bulge or curve of the shoreline though. Similarly, the N direction could cause erosion where that arrow points to the illustrated shoreline, but the wind/waves coming from the NE direction would hit the beach, as shown, at a 90-degree angle, and would not cause erosion at that point. It is very much about the direction of the flow of water and the angle at which it hits the beach, even there are many other factors, some of which I'll talk more about in the future..
Good hunting,
TreasureGuide@comcast.net
M