This chart illustrates how frequently and how strongly the wind blows from different directions through a typical December. The longest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with deep blue strongest. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Petit Port, located 40 km away (25 miles). There are too few 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 dominant wind at Petit Port blows from the WSW. If the rose graph shows a fairly circular pattern, it means there is no strong bias in wind direction at Petit Port. By contrast, dominant spokes represent favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average December, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 1.8% of the time (1 days each December) and blows offshore just 10% of the time (3 days in an average December). In a typical December winds stronger than >40kph (25mph) are expected on 10 days at Petit Port
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.