The graph shows how often 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 suggests the strength, with deep 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 Rosarito, located 41 km away (25 miles). There are not enough 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 Rosarito blows from the WSW. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Rosarito. Converseley, dominant spokes represent favoured directions, and the more dark 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 (light blue) about 10% of the time (3 days each December) and blows offshore 14% of the time (4 days in an average December). Over an average December winds exceeding >40kph (25mph) are not expected, but 0 have winds on the range 30-40 (19-25) at Rosarito
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.