The graph illustrates how commonly and how strongly the wind blows from different directions through a typical year. The largest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with the strongest winds shown by deep blue. It is based on 20068 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to St Simons Island GA, located 39 km away (24 miles). There are too few recording stations world wide to use actual wind data. Invevitably some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the prevailing wind at St Simons Island GA blows from the E. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at St Simons Island GA. Converseley, dominant spokes illustrate favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average year, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 9% of the time (33 days each year) and blows offshore 25% of the time (69 days in an average year). During a typical year winds stronger than >40kph (25mph) are expected on 11 days at St Simons Island GA
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.