The figure shows how commonly and how strongly the wind blows from different directions through a typical September. The longest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with the darkest shade of blue showing the strongest winds. It is based on 1680 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Alexandra Headland, located 43 km away (27 miles). There are insufficient recording stations world wide to use actual wind data. No doubt some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the dominant wind at Alexandra Headland blows from the ESE. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Alexandra Headland. Converseley, dominant spokes show favoured directions, and the more the darkest shade of blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average September, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 7% of the time (2 days each September) and blows offshore 17% of the time (5 days in an average September). During a typical September winds stronger than >40kph (25mph) are expected on 2 days at Alexandra Headland
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.