Swell Models

Computer swell forecasts drive the lions share of internet forecast sites and particularly MSW which was the first to bring free long range model data to surfers everywhere. Understanding how they work will hugely improve your ability to forecast the surf for your local beach.

The Model Spectrum

This is the most complex and also the most important part of understanding how swell models work. Get your head around this bit and you’ll start to avoid the forecasting pitfalls that 99% of surfers get stuck by. The swell model represents the state of the ocean in a particular grid square. It doesn’t track individual waves, or even individual swells instead it simply records how much energy there is in all the waves present. To make this useful it breaks down how the energy is distributed based on period and direction, but just as the model divides the world into a grid to make managing the maths simple the […]

Model Accuracy

Running a surf forecasting website for almost a decade we’ve learnt a very great deal about accuracy and people’s perception of it. We’ve seen surfers arguing time and time again over which of two forecast websites is more accurate when we know they both show fundamentally the same model data. We’ve changed our logo or page designs only to be told that we’ve ruined the accuracy of the forecast! The key issue for most surfers is, as we’ve already touched on, the gap between what a model forecast is telling you and what you think it’s telling you. Or more simply the gap between the incoming swell and the waves on the […]