Surf In Jaco - Forecasting

Observations on surf forecasting from our hotel in Jaco Costa Rica -

Today Surfline predicted wave faces of 3 to 4 feet for the central pacific. Yesterday wave faces were predicted at 2 to 4 feet. Today was considerably smaller than yesterday in South Jaco.

Is there any value in the surfline forecast? Yes, in my experience they can be quite helpful, but you can't just take them at face value. First of all, the bathymetry (bottom contour shape) of the beaches and ocean beyond, the shape of the coast, the land shadow of the Nicoya for some swell directions, all affect how open ocean swell manifests on different beaches.

For instance, Bejuco is on a wide open stretch of coastline with nothing to interfere with the waves banging right up onto the sandbars. The swell comes unimpeded through very deep water and then hits a gradual slope leading to the sandbars which create big peaky waves.

South Jaco beach is shaded by Punta Guapinol which blocks swell out of the south (although it can wrap around which cuts it size) and has shallower ocean in front of it and can be in the land shadow of the Nicoya for some swells.

Consequently, surf heights in south Jaco will typically be 1/3 or so of surf heights in Bejuco although both are covered on the central pacific forecast and receive the same swell.

There is a page on surfline that gives beach specific forecasts but it underestimates the differences in my experience. It gives you a baseline idea of which beaches are going to show bigger waves though.

But I digress.. back to the matter at hand. How come surfline said it would be bigger and it was smaller? Well, surfline could be just plain wrong. I have definitely seen hat happen sometimes. And it was a pretty small difference we were looking at, so that could be the explanation.

But it turns out it was actually a little bigger today than yesterday in Hermosa. Hermosa is only a few minutes south of Jaco and the lovely hotel DoceLunas. Did it get a different swell? Well, yes and no.

If you look at the forecast, you can see there is a detailed forecast tab. This breaks down the individual swells that contribute to the wave height. For today, you can see that the dominant swell was only a little west of due south. Coming almost straight out of the south, it did not make it past the point at the south end of Jaco. I didnt make it up there this morning, but its a pretty sure bet that the waves were considerably bigger in north Jaco.

In general, faces in the north end of Jaco beach will be 10% to 30% taller than in the south, unless the swell is coming from true southwest or more westerly.


For detailed information about wave forecasting for Hermosa Beach and the different breaks on that beautiful three mile stretch of paradise

check out the surf page on our website www.docelunas.com you can find it under activities.