The graph shows how frequently and how strongly the wind blows from different directions through a typical August. The longest spokes point in the directions the wind most commonly blows from and the shade of blue implies the strength, with the strongest winds shown by deep blue. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Castles, located 32 km away (20 miles). There are not enough 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 Castles blows from the SE. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Castles. By contrast, dominant spokes illustrate favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average August, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 14% of the time (4 days each August) and blows offshore 35% of the time (10 days in an average August). In a typical August winds exceeding >40kph (25mph) are not expected, but 2 have winds on the range 30-40 (19-25) at Castles
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.