The figure describes how often and how strongly the wind blows from different directions through a typical October. The longest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with dark blue strongest. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Faro de Trafalgar, located 21 km away (13 miles). There are insufficient recording stations world wide to use actual wind data. Without question some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the prevailing wind at Faro de Trafalgar blows from the W. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Faro de Trafalgar. By contrast, dominant spokes represent favoured directions, and the more the darkest shade of blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average October, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 12% of the time (4 days each October) and blows offshore 25% of the time (6 days in an average October). In a typical October wind stronger than >40kph (25mph) was forecast for only a single days at Faro de Trafalgar
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.