The rose diagram illustrates how frequently and how strongly the wind blows from different directions through a typical southern hemisphere winter. 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 5066 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to A-Bay, located 28 km away (17 miles). There are too few 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 A-Bay blows from the SW. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at A-Bay. On the other hand, 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 southern hemisphere winter, the model suggests that winds are light enough for the sea to be glassy (light blue) about 10% of the time (9 days each southern hemisphere winter) and blows offshore 51% of the time (44 days in an average southern hemisphere winter). In a typical southern hemisphere winter winds stronger than >40kph (25mph) are expected on 9 days at A-Bay
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.