This picture describes how commonly and how strongly the wind blows from different directions through a typical October. The longest spokes point in the directions the wind most commonly blows from and the shade of blue implies the strength, with the strongest winds shown by dark blue. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Castelejo, located 12 km away (7 miles). There are too few 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 dominant wind at Castelejo blows from the WNW. If the rose plot shows a nearly round shape, it means there is no strong bias in wind direction at Castelejo. On the other hand, dominant spokes represent favoured directions, and the more deep blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average October, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 15% of the time (5 days each October) and blows offshore 32% of the time (10 days in an average October). During a typical October wind stronger than >40kph (25mph) was expected for only a single days at Castelejo
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.