This picture illustrates how often and how strongly the wind blows from different directions through a typical July. The longest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with the darkest shade of 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 Posties, located 24 km away (15 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 Posties blows from the SW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Posties. By contrast, dominant spokes illustrate favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average July, the model suggests that winds are light enough for the sea to be glassy (light blue) about 7% of the time (2 days each July) and blows offshore 39% of the time (12 days in an average July). In a typical July winds stronger than >40kph (25mph) are expected on 3 days at Posties
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.