This picture describes how commonly and how strongly the wind blows from different directions over a normal northern hemisphere autumn. The biggest 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 5144 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Vila Praia de Ancora, located 23 km away (14 miles). There are not enough 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 dominant wind at Vila Praia de Ancora blows from the WNW. If the rose graph shows a fairly circular pattern, it means there is no strong bias in wind direction at Vila Praia de Ancora. By contrast, dominant spokes show favoured directions, and the more dark blue, the stronger the wind. Spokes point in the direction the wind blows from. During a typical northern hemisphere autumn, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 21% of the time (19 days each northern hemisphere autumn) and blows offshore 50% of the time (45 days in an average northern hemisphere autumn). Over an average northern hemisphere autumn winds stronger than >40kph (25mph) are expected on 5 days at Vila Praia de Ancora
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.