The rose diagram shows how frequently and how strongly the wind blows from different directions through a typical April. The biggest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with the strongest winds shown by deep blue. It is based on 1638 NWW3 forecasts of wind since since 2007, at 3hr intervals, for the closest NWW3 model node to Leca, located 33 km away (21 miles). There are not enough 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 prevailing wind at Leca blows from the WNW. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Leca. Converseley, dominant spokes represent favoured directions, and the more the darkest shade of blue, the stronger the wind. Spokes point in the direction the wind blows from. Over an average April, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 18% of the time (5 days each April) and blows offshore 33% of the time (10 days in an average April). During a typical April wind stronger than >40kph (25mph) was predicted for only a single days at Leca
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.