The rose diagram shows how frequently and how strongly the wind blows from different directions through a typical northern hemisphere winter. The longest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with the darkest shade of blue strongest. It is based on 5048 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Futami, located 7 km away (4 miles). There are not enough recording stations world wide to use actual wind data. Without question some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the dominant wind at Futami blows from the NE. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Futami. By contrast, dominant spokes illustrate 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 (pale blue) about 1.3% of the time (1 days each northern hemisphere winter) and blows offshore just 5% of the time (0 days in an average northern hemisphere winter). In a typical northern hemisphere winter winds stronger than >40kph (25mph) are expected on 5 days at Futami
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.