This image describes how commonly and how strongly the wind blows from different directions through a typical November. The longest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with deep blue showing the strongest winds. It is based on 1680 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Ile d'Oleron - Grand Village, located 25 km away (16 miles). There are not enough 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 Ile d'Oleron - Grand Village blows from the W. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Ile d'Oleron - Grand Village. On the other hand, dominant spokes illustrate favoured directions, and the more dark blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average November, 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 November) and blows offshore 22% of the time (6 days in an average November). During a typical November winds stronger than >40kph (25mph) are expected on 4 days at Ile d'Oleron - Grand Village
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.