This picture illustrates how often and how strongly the wind blows from different directions over a normal southern hemisphere spring. The largest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with the strongest winds shown by dark blue. It is based on 5144 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Goolwa, located 26 km away (16 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 Goolwa blows from the SSW. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Goolwa. By contrast, 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 southern hemisphere spring, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 11% of the time (10 days each southern hemisphere spring) and blows offshore 32% of the time (29 days in an average southern hemisphere spring). Over an average southern hemisphere spring winds stronger than >40kph (25mph) are expected on 2 days at Goolwa
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.