The rose diagram describes how often and how strongly the wind blows from different directions over a normal February. The biggest 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 1584 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to Digger, located 29 km away (18 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 prevailing wind at Digger blows from the SW. If the rose graph shows a fairly circular pattern, it means there is no strong bias in wind direction at Digger. By contrast, 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. During a typical February, the model suggests that winds are light enough for the sea to be glassy (light blue) about 35% of the time (10 days each February) and blows offshore 79% of the time (8 days in an average February). Over an average February winds exceeding >40kph (25mph) are not expected, but 0 have winds on the range 30-40 (19-25) at Digger
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.