The graph describes how frequently and how strongly the wind blows from different directions through a typical southern hemisphere summer. The largest 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 5048 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Downtowns, located 34 km away (21 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 most common wind at Downtowns blows from the SW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Downtowns. On the other hand, 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 southern hemisphere summer, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 32% of the time (29 days each southern hemisphere summer) and blows offshore 36% of the time (19 days in an average southern hemisphere summer). In a typical southern hemisphere summer winds exceeding >40kph (25mph) are not expected, but 3 have winds on the range 30-40 (19-25) at Downtowns
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.