The graph describes how commonly and how strongly the wind blows from different directions over a normal northern hemisphere spring. The biggest spokes point in the directions the wind most commonly blows from and the shade of blue implies the strength, with dark blue showing the strongest winds. It is based on 4858 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to Repulse Bay, located 33 km away (21 miles). There are too few 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 prevailing wind at Repulse Bay blows from the SE. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Repulse Bay. Converseley, 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. During a typical northern hemisphere spring, the model suggests that winds are light enough for the sea to be glassy (light blue) about 8% of the time (7 days each northern hemisphere spring) and blows offshore 13% of the time (0 days in an average northern hemisphere spring). Over an average northern hemisphere spring winds stronger than >40kph (25mph) are expected on 2 days at Repulse Bay
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.