The figure describes how often and how strongly the wind blows from different directions over a normal May. 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 1734 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to Alisitos, located 13 km away (8 miles). There are insufficient recording stations world wide to use actual wind data. Invevitably some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the dominant wind at Alisitos blows from the SW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Alisitos. On the other hand, 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. During a typical May, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 20% of the time (6 days each May) and blows offshore 26% of the time (8 days in an average May). Over an average May winds exceeding >40kph (25mph) are not expected, but 0 have winds on the range 30-40 (19-25) at Alisitos
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.