The figure illustrates how commonly and how strongly the wind blows from different directions over a normal February. 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 1584 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to St Gilles Croix de Vie, located 22 km away (14 miles). There are insufficient recording stations world wide to use actual wind data. No doubt some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the most common wind at St Gilles Croix de Vie blows from the WSW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at St Gilles Croix de Vie. Converseley, dominant spokes represent favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. During a typical February, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 6% of the time (2 days each February) and blows offshore 42% of the time (12 days in an average February). Over an average February winds stronger than >40kph (25mph) are expected on 4 days at St Gilles Croix de Vie
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.