The figure shows how commonly and how strongly the wind blows from different directions over a normal northern hemisphere summer. The longest spokes point in the directions the wind most commonly blows from and the shade of blue implies the strength, with dark blue strongest. It is based on 5080 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Rivermouth_Wailuku, located 10 km away (6 miles). There are too few 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 most common wind at Rivermouth_Wailuku 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 Rivermouth_Wailuku. Converseley, 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 northern hemisphere summer, the model suggests that winds are light enough for the sea to be glassy (light blue) about 1.2% of the time (1 days each northern hemisphere summer) and blows offshore just 1.3% of the time (1 days in an average northern hemisphere summer). Over an average northern hemisphere summer winds exceeding >40kph (25mph) are not expected, but 6 have winds on the range 30-40 (19-25) at Rivermouth_Wailuku
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.