This picture shows how commonly and how strongly the wind blows from different directions through a typical northern hemisphere winter. The largest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with dark blue strongest. It is based on 5048 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Repulse Bay, located 33 km away (21 miles). There are insufficient 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 Repulse Bay blows from the ESE. If the rose graph shows a fairly circular pattern, it means there is no strong bias in wind direction at Repulse Bay. By contrast, dominant spokes show favoured directions, and the more dark blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average northern hemisphere winter, the model suggests that winds are light enough for the sea to be glassy (light blue) about 3% of the time (3 days each northern hemisphere winter) and blows offshore just 17% of the time (0 days in an average northern hemisphere winter). During a typical northern hemisphere winter wind stronger than >40kph (25mph) was forecast for only a single 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.