Data quality
High resolution models
For the next 36 hours, the short range forecast, high resolution data are used. The high resolution data base is currently in the first stage of development. More and more areas are permanetly added.
We use 10km, 15km and 16km resoluted data in the weather forecast. These cover different areas and come from different National weatherservices. Be aware that some of this forecasts, are specifically designed for the sea and are not valid on the land.
High res Numerical Weather Prediction data are generaly generated by the respective National Weather Service. There is no high resolution global model.
To ensure the best data quality, we have to use data from different National Weather Services.
Forecast data from national weather services are trusted sources and guarantee a good forecast data quality because of the amount and quality of observation data, which are the point of origin for the calculations. National weatherservices usually have the most complex observation database, which are assimilated into the model calculation, containing synoptic data, data from radiosonde, satellites, radar etc. This is particularly the case in countries like Europe, where weather data are with costs.
There are private companies, who runs their own model forecasts and offer a good data resolution. But the data resolution is not the only benchmark for the quality of model forecasts. This depends also on the amount and quality of observation data and National weatherservices are usually best equipped with all available observation data.
We use high resolution data in the short range forecast for the next 36 hours. Because these are generated by different National Weatherservices, they have different resolutions. The resolution is not the same in every part of the world. In Geo-wind forecast data from different sources and model chains are combined in one display.
Global models
We use the global model GFS from Noaa with a resolution of 0.5° for low zoomlevels and for the long range forecast.The worldwide wave forecast from Noaa has also a resolution of 0.5° This global models are calculated for the whole world and enables a zoom out until the global world view.
How many kilometers are 0.5° ?
The global forecast GFS with a resolution of 0.5° differs in the length expressed in km according to different latitudes. On the equator at latitude 0°, 0.5° complies with ~55km and in northeuropean at latitude 60° , 0.5° correlates ~28km.
Global model and Hires model in one display
In the short range forecast different models are used on different zoomlevels.
Between zoomlevel 1-7 the global model GFS is displayed. From zoomlevel 8 normaly higher resoluted data are visualised.
Because we use high resolution data for deeper zoomlevels, which comes from other sources and were generated from other model chains, it can happen, that there are differences in the forecast, zooming from one zoomlevel to another.
For example, if you change from zoomlevel 7 to zoomlevel 8 in shortrange, you leave the global model and enter the highres forecast, which is more detailed, because of the better resolution. But it can also be, that it differs more than that, because this are models from different Weather services.
In this case, you can compare the global forecast from Noaa (GFS) for this place and the high res forecast from another weather service. This are no mistakes, but reflects the uncertainty of numerical forecasts.
Wave forecasts
Geo-wind uses the global wave forecast from Noaa with a resolution of 0.5°.
Higher resolutions are also available from different sources.
Most, what is explicated above for weather data is also the case for wave forecast data.
We offer two parameters for the wave forecast:
- 1. Significant Sea wave height, speed and direction
- 2. Swell wave height and direction
Here the WMO definition of wind waves and swell:
"Wind wave or wind sea: Waves raised by the wind blowing in the immediate neighbourhood of an observation site at the time of observation.
Swell: Any system of water waves which has left its generating area (or observed when the wind field that generated the waves no longer exists)."
Significant Sea waves are combined from different superimposed waves,wind waves and swell, which may come from different directions. Therefore different directions are shown.
The significant wave height is the mean wave height of the one third highest waves.
We use the WMO Sea State Code of Douglas
Sea Waves
Degree | Height (m) | Description |
0 | no wave | Calm (Glassy) |
1 | 0 - 0.10 | Calm (Rippled) |
2 | 0.10 - 0.50 | Smooth |
3 | 0.50 - 1.25 | Slight |
4 | 1.25 - 2.50 | Moderate |
5 | 2.50 - 4.00 | Rough |
6 | 4.00 - 6.00 | Very Rough |
7 | 6.00 - 9.00 | High |
8 | 9.00 - 14.00 | Very High |
9 | 14.00+ | Phenomenal |
More Information on the WMO Sea State Code, you can find in the WMO Document: WMO-8-Part-II-Ch-4 Chapter 4 (Marine Observations), Part II, of WMO No. 8, Guide to Meteorological Instruments and Methods on Observation
First version of Geo-wind
In the first Geo-wind version we start with high resolution for meditérranean, canares, atlantic(Madeira) and europe. The wave forecast in the most of this areas is 20km. High resolution data are added continuously for more and more places of the earth.
To see the available resolutions, price categories and prices go to the products page .