“Waves are not measured in feet or inches, they are measured in increments of fear.” Buzzy Trent
One of the most common things I hear down the beach is that the surf forecasting website Magicseaweed is always wrong, leading to the derogatory name Tragicseaweed or Tragic’s. How much truth in this is there though? Is it as bad as everyone says, or are people not interpreting the data efficiently?
In my humble opinion it is clearly the latter. I personally use a combination of Magicseaweed and older traditional forecasting methods too, namely checking the pressure charts; however, I find Magicseaweed an incredibly good tool and believe it has a high accuracy rate when I take a number of other factors into consideration. This is where some surfers get it wrong and wonder why that 6-7ft swell Magic’s predicted a week earlier is now only 2ft dribble on the eyeball check, or even more amusingly, sometimes they don’t check the surf at all because Magicseaweed says it will only be 2ft, however, in reality they missed out on 4-5ft pumping barrels.
So with such discrepancies, how is it I can say it has a high accuracy rate? Well to me I think its pretty accurate, but you have to not see what you read but read what you see. The following, without giving away all of my secrets, are a few basic tips from a Jersey point of view on getting the most of the Magicseaweed forecast.
Don’t reach for the stars!
Whilst Magicseaweed’s 1 to 5 gold star rating may look pretty, they are irrelevant in isolation. This is simply the biggest and funniest complaint I hear about Magicseaweed; ‘It gave 5 stars but the surf is rubbish’.
Commonly, especially with social media, there is mass hype when the 5 stars light, but this doesn’t always mean it will be good. They usually appear with large wave heights and super long period swell (more on that later) forecast; however, frequently large wave heights and super long periods don’t always equate to good waves on the beach; most beach breaks can’t handle long periods and beaches will close-out. Of course swell direction, sandbanks, wind conditions etc. can all go against this statement and it could be epic. On other occasions the tides might not be ideal for the type of swell, or locally generated weather conditions might throw in a spoiler.
At the other end of the star scale, there may be no stars lit up and a small wave height forecast; however, there could be a sneaky small long period secondary or even tertiary (third) swell that lights up the beach.
In summary, count the stars and you will be disappointed.
Pied de perche (a Jersey foot)
The description of a head-high wave in Jersey can range anywhere from 2ft to 6ft, although generally 3ft is most commonly used to describe head-high, which can appear odd to none surfers and beginners. If you read the help pages in Magicseaweed they describe in detail how they record and display wave heights; it is unlikely the same as you and I call it. One important thing to note is that the wave heights will mean something different for each swell taking into account other factors that I will repeat often, weather, tide, wind, direction, period etc.
My advice would be not to get get hung up on forecast wave heights in isolation, gauge what you see whilst considering all the other available factors.
Mind the gap
Period, the time it takes between two waves breaking, is the first thing I look at when I check the forecast; in a nutshell the larger the period the more powerful the swell. Generally speaking, anything below 6 seconds will be flat, 6-9 seconds will give no or little surf unless the wave heights are high (6-8ft plus), medium period swell, 10-13 seconds will mean surf and can be an ideal period for beach breaks, long period swell, 14-20 seconds plus are great for the reefs.
Examples; 6-7ft wave heights at 8 seconds might only give you a waist to chest high wave, whereas 1ft wave heights at 18 seconds could give head high plus barrels.
Tide and time waits for no man
So you understand the wave heights and period, but still the forecast is wrong. You probably forgot to factor in the tides.
Jersey has some of the largest tidal ranges in the world and this has a huge effect on the surf conditions, a matter all too often overlooked when people check the surf forecast. A neap tide will decrease forecast size and a spring tide will increase it. Through gained experience and knowledge, after first considering period, I adapt forecast wave heights to suit different tidal conditions.
Multiple swells and directions
Another area often overlooked is that with various different weather systems on any given chart, there can be multiple swells running at the same time. A long period secondary or even tertiary swell can bring in surprisingly good conditions. When forecasting a couple of surfing events in recent years, we were criticised for making calls on poor forecasts, those criticising had failed to consider the secondary swells, which on both occasions was around 1ft at 12-14 seconds. On both occasions we were blessed with great fun competitive waves leaving a few eating humble pie.
Another area that can be overlooked is swell direction. Due to Jersey’s position tucked up the English Channel, most surf we get will come from the west; however, Jersey can get swells from all other directions too; some even big enough to create swell in different areas of the island. One thing to watch though is when a secondary or tertiary swell is running directly against the primary swell. This can make a considerable dent in incoming wave heights leading to more uneducated forecast hoax claims.
Surf forecast snobbery
‘But I only use Wind Guru, its far more accurate.’ Each forecast service is only as good as how you interpret and understand the data, and that means all of the above applies.
When things do go wrong
We all know that the weather can change, as do the daily, and on occasions even hourly, forecasts. With this in mind, why should surf forecasts be any different?
The surf forecast websites collect data from numerous sources and run various different models, Magicseaweed for example run 20 different swell models. There will be times when the models all align and other times when they widely differ, so naturally the more they differ, the probability of the forecast being accurate, particularly a few days out, drops.
Keeping on top of the forecast and learning patterns is a great way of anticipating what might happen. I generally have more faith in long range forecasts during stable periods of weather rather than changeable weather. In unstable weather patterns, I will often take the medium and long range forecasts with a pinch of salt and will try to guess and anticipate what changes may occur.
Sometimes though even with all the knowledge and data available, things don’t quite happen as expected. These occurrences don’t occur too often for me though, so I just accept them as one of those things when they do happen.
Magicseaweed is a great tool to have in the arsenal for surf forecasting; however, never read it just on face value. The more you use it and start noting the patterns and links between the forecasts and what you see down the beach, the more you will dial into it and more accurate you will find it.
I have no connection or affiliation with Magicseaweed, I just happened to select Magicseaweed for this article as this is the one I hear the most grumbles against.