The Basics of Reading Surf Forecasts
When you are getting used to surf forecasts it is important not to get caught up with all the masses of information available, start with understanding a few key pieces that will provide you with enough accurate information to find good waves. It is important to remember however that you are looking at a forecast and as such conditions on the day may change from what is predicted/expected.
The swell is the most likely piece of information to be correct, as it is measured by many buoys out at sea and closer to shore which track it’s size, period and direction.
The swell is the lines of raised water that when reaching the beach/reef form into breaking waves. The swell period is the time, in seconds, between the highest point of one line of swell to the next. As the period increases, the wave size and power will also increase.
For example, if the swell is heading straight towards your break at 3ft with a 10 second period chances are the waves will be around 3ft, with a period of 15 seconds the breaking wave size could increase to around 4/5ft or even bigger.
If the direction of the swell means it has to wrap around a corner, for instance a headland, the wave size will be reduced, the sharper the corner the more size and power will be lost.
Wind speed and direction can affect the wave shape and quality quite dramatically, an offshore wind (wind blowing from land out to sea) will hold up the waves and prevent them from breaking early, creating a bigger, steeper wave than normal for swell size of that size.
An onshore wind (blowing from sea towards the land) will make the waves break earlier than usual and is more likely to be less steep (a spilling wave) the wave will also likely be slightly smaller, as the wind will prevent the wave from building to its full swell height.
Cross shore winds are more likely to create choppier conditions and as such can be a bit harder to accurately predict how they will affect the waves. That being said, a cross shore wind coming from the right direction and at a good speed can create some extremely good waves.
When reading the surf forecasts it is important to know about your break/beach. Knowing which way your break faces, how and where the waves break, where on the beach you can find shelter from certain wind directions and how the conditions change at different stages of the tide are all key bits of information that will determine the conditions on a given day.
By learning how to interpret these few pieces of vital information, you will be able to accurately predict the conditions and when the waves will be best for you. Of course the best way to learn how to read a forecast is to get in the water as much as possible and test if you got your predictions right.
You can find more information on how wind affects the waves on our YouTube Channel, we ran a virtual theory session last year for our Big Green Surf Gals, Ladies Surf Club which you can view here - https://www.youtube.com/watch?v=DwymLNC9KJs