The rose diagram shows how frequently and how strongly the wind blows from different directions through a typical August. The longest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with deep blue showing the strongest winds. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Point Lonsdale, located 25 km away (16 miles). There are not enough 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 Point Lonsdale blows from the SW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Point Lonsdale. By contrast, dominant spokes illustrate 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 August, the model suggests that winds are light enough for the sea to be glassy (light blue) about 7% of the time (2 days each August) and blows offshore 36% of the time (11 days in an average August). During a typical August winds stronger than >40kph (25mph) are expected on 4 days at Point Lonsdale
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.