You’re probably wondering how to read Windguru, aren’t you?
It’s normal! Windguru is THE reference for weather forecasts for kiteboarding enthusiasts like us. With this tool, you can anticipate wind strength and get an overview of the upcoming navigation conditions at your favorite spot.
Understanding weather models and interpreting Windguru data may seem a bit complex, but don’t worry, we’ll explain it all in detail.
The ultimate goal? Being in the right place at the right time to make the most of your kiteboarding session.
So, ready to find out how Windguru works? Let’s do this!
The first step is to find your kiteboarding spot on Windguru.
The quickest way is to do a direct search from Google by typing Windguru + the name of your spot.
For example, when we want to know the wind conditions for the spots in Tarifa in the coming days, we often search in Google: “Windguru Los Lances” or “Windguru Valdevaqueros”.
It’s also possible to search for different spots directly from Windguru itself. You can do this at the top left of the homepage on the Windguru website, next to the site’s logo.
The models are numerous: WG – GFS13 – WRF27 – ICON 7 or Zephyr-HD 3… what are they?
The models and grids available on Windguru correspond to the different tables found by scrolling on the website or the app. You may notice significant differences in forecasts for the same date.
So, how can we understand clearly what these different models are for?
The first points to distinguish on Windguru are the weather forecast models used. They are distributed in horizontal tables and each have a defined forecasting objective based on data, precision, and time scale.
A weather model is a computer prediction that attempts to define how the weather will behave in the hours and days to come based on numerical modeling of atmospheric conditions. It’s clearly a weather scenario prediction made by calculators.
There are different calculator models according to their specializations, but also because there are different calculation algorithms.
Furthermore, the input data that these algorithms exploit can be different and variable, and can come from satellite observations, weather stations installed all over the globe, as well as sensors embedded directly on airliners or merchant ships.
Here are some of them:
GSF 13 km (Global Forecast System) USA
WRF 3 km et 9 km (Weather Research and Forecasting)
ZEPHR-HD 4 km et 9 km (Modèle Zephyr) Spain – Portugal
ICON 7 km (Icosahedral Nonhydrostatic) Europe
HIRLAM 7,5 km (High Resolution Limited Area Model) Europe
About the reliability of weather models:
A model is nothing more than a computer simulation. It simulates the behaviors of the atmosphere, and each model incorporates a vast number of parameters and variables into its calculations. These are supercomputers that attempt to forecast the weather. Their reliability is not absolute; sometimes, some of them get it wrong, as they say.
The ideal approach is to compare them with each other to obtain a reliability index closest to reality.
In Tarifa, when we consider spots like “Los Lances” or “Valdevaqueros,” we have on Windguru no less than 9 forecast models. There are 5 for general weather forecasting (which particularly interests us for wind) and 4 for wave and tide forecasts.
The first table, WG (Windguru Model Mix), is not a model but a weighted average of all the models included on Windguru.
Very useful for getting a clear view of upcoming trends in the coming days, but not very detailed in resolution.
Is it for immediate consumption or for the days to come?
Each forecast model is marked by a resolution indicator expressed in kilometers. In essence, the mathematical model uses a grid to dissect the ground. The larger the surface, the more time the calculator can predict, but it will be less accurate than a model based on a smaller surface (higher resolution) that offers only a short prediction time.
The WRF 9 km, which has a surface resolution of a square of 9 km on each side, will have a longer available forecast duration (more than 3 days), but it will be less accurate than a model with a higher resolution, such as the WRF 3 km, which will only provide a maximum forecast duration of 48 hours.
In summary, the wider the resolution of the observed model, the more it can be interpreted as a trend.
This is perfect when planning your kiteboarding trip to keep an eye on forecasts a few days in advance.
Conversely, the higher the resolution model you look at, the more reliable the data will be, but for a shorter duration.
If you are on-site, I recommend mainly considering Windguru models with a resolution of less than 7km to forecast upcoming sessions, for the current day or the next day.
A model is never infallible; it’s merely the result of a complex calculation that determines a forecast.
The ideal approach is always to compare different models with similar resolutions. For example: WRF 3km vs Zephyr-HD-4km.
This allows you to determine reliability in forecasts, a sort of confidence index.
Each table contains a set of data and is read vertically for the days and hours, and horizontally for the forecast data.
Here is the list of the main data on Windguru that are crucial for kitesurfing.
This is the average wind speed expected over a 10-minute sample and at a height of 10 meters above ground level.
By default, wind is expressed in knots (1 knot = 1.852 km/h), and it is possible to display other speed units by clicking on the “wind speed” line.
The color provides an intuitive indication of speed. The warmer the colors (red, purple, etc.), the stronger the wind will be.
These indicate a difference between the constant average wind and an estimate of variations caused by terrain or particular wind effects such as thermals and other venturi effects.
In general, in Tarifa, a stronger difference is observed when the wind comes from the East (Levante) because it has to pass through the small mountains of the natural park, whereas the Poniente is often very stable.
Symbolized by wind rose arrows.
This is a wind FROM the NORTH.
Another example: wind coming from the Southwest:
It allows you to define the wind direction at the spot, Side / Side-On / Side-Off / On-Shore / Off-Shore.
Expressed in degrees Celsius, evaluated at 2m above ground level. Ideal for choosing the appropriate wetsuit.
Windguru does not indicate water temperature, so you will need to search for this data on other websites.
Expressed in %, it gives an indication of the amount of clouds present at different altitudes.
Basically, the grayer it is, the more overcast the sky will be.
Represents a quantity of rain in mm/m² over a 3-hour time scale.
Important data in kitesurfing practice because sailing in the rain is not very pleasant, but more importantly, you need to consider possible storms. A change in wind direction or intensity combined with rain is not a good sign.
With this data, you are now able to read the wind forecasts on Windguru and determine where and when you should be to catch a fantastic kitesurfing session.
Some models incorporate additional data such as wave direction and periods as well as tides, which can be very useful if you are a wave hunter.
Note: Don’t hesitate to consult the page of the best kitesurfing spots in Tarifa based on the wind direction.
At Tarifa, there is a weather buoy that indicates real-time wind, no longer just a forecast but a real-time display of the wind.
It is located at the football field at the outskirts of the city. To access it, go to the top left corner of the Windguru Los Lances table.
By clicking on the data from the football field buoy, you will access a graphical display of the wind and gusts in real-time.
This tool is very handy to know what is happening at the spot at any given moment. A second weather station is installed at Spin-Out for Valdevaqueros.
This real-time weather station is not exclusive to Tarifa but exists for many other spots, thanks to a service of purchasing/renting weather stations to install at the spots.
Of course, even though Windguru is probably one of the best weather forecasting sites for both kitesurfers and windsurfers, there are other weather forecasting sites that are also very interesting.
Also very well known among fishermen, paragliders, kitesurfers and surfers, Windfinder.com is a weather forecasting site that offers only two model view systems. Probably with the aim of making it easier to use.
The forecast block of Windfinder or forecast only shows the base of the GFS model with a resolution of 13Km, so it is impossible to access the other weather models we are used to on Windguru.
This is the advantage of Windfinder, the superforecast seems to be a condensation of fine mesh models (7 km) but, we don’t know exactly on which models Windfinder bases its forecasts.
Windy.com offers an interesting interactive map which includes forecasts from several weather models such as :
ECMWF – GFS – ICON – NEMS
One of its main advantages is that it also offers rain radar integration and satellite data integration for cloud formations and hurricane tracking.
Windy is a complete, interactive and easy to use site, its main drawback is that on the mobile application only the GFS27 model is available in a free version, a pro formula is proposed for a subscription fee of 59€/year.
So, Windguru, Windfinder, and Windy seem to form the top 3 of the best weather forecasting websites and applications.
There are of course other weather forecasting sites which have other advantages and disadvantages, they have not been mentioned much in particular: Ventusky; Weather-Forecast; AlloSurf and many others that are still to be discovered and explored.
See you on the water