This picture 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 indicates the strength, with the strongest winds shown by dark blue. It is based on 5066 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Duranbah, located 19 km away (12 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 prevailing wind at Duranbah blows from the SE. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Duranbah. By contrast, dominant spokes show favoured directions, and the more dark 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 (pale blue) about 8% of the time (7 days each southern hemisphere winter) and blows offshore 31% of the time (9 days in an average southern hemisphere winter). During a typical southern hemisphere winter winds stronger than >40kph (25mph) are expected on 2 days at Duranbah
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.