The figure illustrates how commonly and how strongly the wind blows from different directions over a normal May. The biggest 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 1488 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to Bridgetown Harbour, located 17 km away (11 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 prevailing wind at Bridgetown Harbour blows from the NNE. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Bridgetown Harbour. Converseley, dominant spokes show favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. During a typical May, the model suggests that winds are light enough for the sea to be glassy (light blue) about 0% of the time (0 days each May) and blows offshore just 9% of the time (0 days in an average May). Over an average May winds exceeding >40kph (25mph) are not expected, but 0 have winds on the range 30-40 (19-25) at Bridgetown Harbour
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.