Several factors influence the quality of wind or wind power forecasts. For example, it is expected that forecasts errors grow with forecasting horizon, and that forecasts get less accurate in zones of complex topography.

WPred constantly records the meteorological observations reported every hour at more than 3500 airports in the world known as “METAR reports”. Twice a day, wind predictions are performed by WPred forecasting system for these locations at a height of 10m. At the end of each month, graphical comparisons between observed and forecasted values of wind velocities are produced to provide a visual way to verify forecasts accuracy.

Verify our wind forecast accuracy by selecting an airport close to your location of interest, as well as a particular month. To do this, click on the map in the specific zone of interest, until you see green balloon symbols indicating the presence of an airport. Selecting the balloon with the mouse click will open a box displaying the station ID in which you can further select a particular month. Once a month has been selected, a graphic will appear in the lower section of the browser. In this graphic, the red square symbols represent the 10m-high wind speed observations while the blue and green lines correspond to the 00Z and 12Z forecasts. The forecast horizon used here is 6 days ; after six days, it is therefore normal that for a given moment in time, 12 forecasts are superimposed. To highlight the growth of forecast error with forecasting horizon, the width of the lines representing the forecasts changes accordingly with the forecast horizon: it is set bigger for the first two days, then smaller and smaller for the further two-day periods.