These colours are determined by the combined variables of swell height, period, direction plus wind direction and speed to give an overall quality of conditions. The 1-5 star rating indicates the height and power of the swell.
free surf forecasting
Stars show you the height and power of the swells.
Sometimes you just got to surf whether its onshore or offshore, the star ratings aim to show you the power and height of the swells by computing swell direction, power and period the ‘e’ symbol shows you an energy rating out of 1000.
The subjective nature of surf heights
Surf heights around the world can be a subjective matter so we take the raw swell data and convert it to what we hope is an accurate breaking size on the shore.
Free 16 Day Global Swell Charts
We are building a hi resolution searchable Global swell chart that is in beta release now on the app and here
Frequently Asked Questions
Where do you get your data from?
Firstly we are not using an API – (Which means using at a cost someone else’s data) – we have built our own lean system from the ground up using raw data and our own programs. And will even offer our data to developers to build cool stuff for free
There is much speculation over the accuracy of the raw data from the different raw models we use and although the Euro Model runs at a higher resolution against the GFS (22km vs 13km) it will only run out to 10 days and we know that being able to see if The Atlantic might offer some action from a flat spell in the next week or two is very valuable to you. So we will (as other forecast sites do) use the GFS model out to 16 days (because thats how far it forecasts out too) to give you that insight we will blend in higher resolution European models closer to the current day to refine those all important winds.
After studying metrological data for many years there is a consensus that whilst all models differ in resolution and accuracy, in terms of the data that is needed to forecast the quality of the swell and wind needed to plan your time is consistent amongst the different models 1-7 days out.
No matter how much additional modelling other forecasting sites claim to run their data through they are all being fed in part by a $500 million government weather model (upgraded in 2022) or and a blend of other models such as the ECMWF (Euro Model) & ICON-EU .
Tidal data was supplied by the British Oceanographic Data Centre as part of the function of the National Tidal & Sea Level Facility, hosted by the Proudman Oceanographic Laboratory and funded by the Department for Environment, Food & Rural Affairs and the Natural Environment Research Council.
How do you process your data?
All the data whist extremely complex in its raw GRIB format (General Regularly distributed Information in Binary form) is free, we will run this data through some some complex software that we have written that will fetch the data automatically every time the model is updated usually every 3-6 hours, this will be processed on our server and presented to you in what we hope is easy to understand and concise format.
We wont manually adjust algorithms based on requests for each spot we will present the data as it is and you can choose to use that data alongside your local knowledge. Some of the data used will be fed by ultra high resolution models that will take into consideration coastal refraction and shadowing.
Will you be adding more locations?
Yes we will – but we are still fine tuning the model against spots we know well so we get the model performing well, if you want to help us build a forecast for your spot drop us an email and we’ll be happy to look at it.
How will you be commercially viable?
The answer is we don’t know yet…were just a small bunch of enthusiastic Cornish surfers & coders. We don’t have a 35m annual dollar budget, we don’t have any start up capital or any angel investors….maybe we will start a small subscription fee, maybe we’ll just use some ads…but for now its free and its staying that way.
Who are you?
Swellcloud is an outcome project from years of studying metrological data and coding as a hobby by Alec Short a long-time surfer from Porthleven, Cornwall. Hes also got a couple of mates on board to help out – local businessman Kelvin Batt, Steve England from Orca Surf and Toby Parkins from Head Forwards. Please get in touch if you’d like to discuss the venture further
Give us a try its totally free
We are just a small group of enthusiastic surfers with zero budget...please bear with us whilst we upgrade and improve.
