The rose diagram describes how frequently and how strongly the wind blows from different directions over a normal October. The longest 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 deep blue. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Broadhaven South, located 13 km away (8 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 prevailing wind at Broadhaven South blows from the WSW. If the rose graph shows a fairly circular pattern, it means there is no strong bias in wind direction at Broadhaven South. 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. During a typical October, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 8% of the time (2 days each October) and blows offshore 19% of the time (2 days in an average October). Over an average October winds stronger than >40kph (25mph) are expected on 4 days at Broadhaven South
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.