The figure illustrates how frequently and how strongly the wind blows from different directions over a normal December. The largest 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 showing the strongest winds. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Praia da Rocha, located 12 km away (7 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 most common wind at Praia da Rocha blows from the WSW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Praia da Rocha. By contrast, dominant spokes show 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 December, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 1.6% of the time (0 days each December) and blows offshore just 6% of the time (1 days in an average December). Over an average December winds stronger than >40kph (25mph) are expected on 2 days at Praia da Rocha
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.