Reading a surf forecast is essential to being able to score waves when its firing and save on gas when it’s not. It provides the most relevant swell information and gives you an idea of what conditions are like. Although cams give you a real time look of the beach, reading the forecast in depth will give you greater insight into what conditions are like now and how they’ll be in the future. There are many surf forecasts out there, but to keep it simple I like to use Surfline for their surf reports and Stormsurf for their swell models and buoy readings.
To start, here are some main pieces of terminology that you want to know:
Swell - Energy that has been transferred into the water by wind, typically by storms that occur out in the ocean. Stronger storms produce more energy leading to bigger sells.
Swell Height - The height of the swell as measured from trough to peak. It’s calculated as the average height of one third of all the waves being measured. This alone does not determine the wave size that you’ll be surfing, and will depend on a number of other factors.
Swell Period-The amount of time in seconds for a complete wavelength to travel up and down, typically measured between wave crests. Will usually range from 4-22, with longer swell periods meaning that that the swell has more energy, and will produce bigger waves.
Swell Direction - The direction that the swell is coming from. If the swell is hitting your region directly with little to no obstruction, then you will get bigger and better wave quality. Swell direction is extremely important in surfing.
Wind - Describes the speed and direction of the wind, typically measures in knots. The best conditions occur when there’s no wind, but offshore winds, which blow from the shore out to the sea, can cause waves to become steeper. This is because they blow against the wave causing it to break slower. Onshore winds are the opposite, causing the waves to close out.
Tide - The periodic change in water height, going from high to low twice each day. Is caused by the gravitational interaction between the Moon and Earth. Some spots favor a specific tide, due to the bathymetry at a wave break.
You want to combine different pieces of information from the surf forecast. For example, if it shows a wave height of four feet at a swell period of 10 seconds, then the waves breaking will be 6ft. If its four feet at 20 seconds then there will be 9ft breaking waves. If wind is minimal or at an offshore, and the tide is right, then there will be good surf-able waves.
Along with knowing how to read the forecast, you also want have general knowledge of the spot you’re surfing at. What kind of break is it, which swells work best, and what the tide needs to be to produce good waves. Pairing these different understandings together, you’ll have an idea of what the waves will be like. I also like to use swell and weather models, which will tell you what conditions might be like in the coming days and weeks.
If you have any additional questions about reading the surf forecast be sure to reach out! We have a talented team of riders always willing to help their local surfer out.