Statistiques de Vent de Ammonias, moyennes sur Automne depuis 2006
This picture shows how often and how strongly the wind blows from different directions over a normal northern hemisphere autumn. The largest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with deep blue strongest. It is based on 7252 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Ammonias, located 37 km away (23 miles). There are insufficient 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 Ammonias blows from the S. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Ammonias. On the other hand, 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 autumn, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 0.4% of the time (0 days each northern hemisphere autumn) and blows offshore just 0.5% of the time (0 days in an average northern hemisphere autumn). Over an average northern hemisphere autumn winds exceeding >40kph (25mph) are not expected, but 1 have winds on the range 30-40 (19-25) at Ammonias
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.