The graph shows how commonly and how strongly the wind blows from different directions over a normal August. The largest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with deep blue strongest. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Farol da Barra, located 5 km away (3 miles). There are insufficient 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 Farol da Barra blows from the SSE. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Farol da Barra. On the other hand, 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 August, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 0.5% of the time (0 days each August) and blows offshore just 0.6% of the time (0 days in an average August). Over an average August winds exceeding >40kph (25mph) are not expected, but 1 have winds on the range 30-40 (19-25) at Farol da Barra
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.